Amazon Polly – Text to Speech in 47 Voices and 24 Languages - <AUTHOR> https://aws.amazon.com/blogs/aws/polly-text-to-speech-in-47-voices-and-24-languages/ <comment><USER2> > "I can't embed sound clips in this post"

You can read this as: We're pleased to announce our really cool TTS feature that took a lot of engineering know-how and effort ... but you'll have to click through, because we can't seem to get around the limitations of our CMS to embed audio content in a blog post.

</comment><comment><USER3> I was trying to figure out an affordable way to send "Read Later" articles in voice to mobile device, either as podcast or other format, to keep myself relevant while driving to/from office.

I realized this tool might not be cheap, since it may take the voice actor/actress 2 hours per day to produce my content (2-hour driving commuting per day for me). To get familiar local accent, it costs ~$36 in Australia, and maybe slightly cheaper for US accent. The value it brings me can hardly justify the cost.

Now, with Polly, things changed - it produces reasonable voice, and 2-hour content would only cost ~$0.3. I decided to launch my service as soon as Instapaper approves my API request.

At the same time, put your email here: [http://readlater.launchrock.co/](http://readlater.launchrock.co/)

<comment><USER4> I've built this here: [https://narro.co](https://narro.co) (I haven't built into the Polly voices yet, but it uses Ivona currently, Polly's precursor.)

<comment><USER4> We just released options for all the available Polly voices this morning!

</comment></comment></comment><comment><USER5> One thing I wish more services like this offered is non-speech sounds. CereVoice, for example, lets you insert laughs, coughs, sighs, etc and it can really enhance the output in some cases. Google's WaveNet also manages to simulate the catching of one's breath during particularly long utterances, although I realize it uses a completely different technique (neural net vs. concatenative synthesis).

My biggest problem with CereVoice, though, has been its terrible web API. It doesn't support streaming output, so it renders the audio to an Amazon S3 bucket and then returns a URL, which is pretty inconvenient (and slow). You have to do the same for transcripts, too. So, if you want everything, you have to make 3 separate HTTP requests and parse 2 XML documents for one round of synthesis.

IBM Watson's TTS API gets it right, imo. Its streaming mode returns audio frames and transcripts over a WebSocket connection.

</comment><comment><USER6> After that WaveNet speech synthesis demo, none of these sound even remotely good.

[https://deepmind.com/blog/wavenet-generative-model-raw- audio...](https://deepmind.com/blog/wavenet-generative-model-raw-audio/)

<comment><USER7> Different optimizations. WaveNet (depending on hardware and configuration) takes hours to tens of hours per second of audio, but sounds really good. Polly can create audio faster than you can listen to it.

</comment></comment><comment><USER8> Wish we had seen this a few days ago before dropping funds on a human to record for us. I played with several different voices and ran it on a text corpus that we gave to the human, and in some cases I would say this even sounds better.

Computer generated voices feel most robotic when their intonation of a word is abnormal or their pauses between words make the sentence feel choppy. The intonation and natural pauses between words is very good for all of the main voices.

The Japanese voice Mizuki was the most comical addition, since I can't think of a real situation where she would ever actually be used. Mizuki speaks Engarish (the Japanese version of English) beautifully, but any Japanese person who can understand Engarish will also understand English. Also, Mizuki doesn't add the correct vowel ending to all words, e.g. she correctly says "cheezu" for "cheese", but says "steku" instead of "steki" for "steak".

<comment><USER9> >any Japanese person who can understand Engarish will also understand English.

My impression is that it's actually quite common for Japanese people to understand Japanese accented English more easily than a native English speaker.

>she correctly says "cheezu" for "cheese", but says "steku" instead of "steki" for "steak".

"Suteeku" sounds like what a Japanese person who knows English well but has a strong accent might say. "Suteeki" is more of a corrupted loanword.

<comment><USER8> > My impression is that it's actually quite common for Japanese people to > understand Japanese accented English more easily than a native English > speaker.

This is actually very true, made me think back to many situations in Japan where adding a strong Japanese accent to my English words made it comprehensible to the listener (just as adding a Japanese accent to the generated speech makes it nearly incomprehensible to a non-Japanese speaker).

</comment></comment></comment><comment><USER10> Audio examples are available here: [https://aws.amazon.com/polly/](https://aws.amazon.com/polly/)

<comment><USER11> They don't sound great to me. I was hoping to build a service around this, but hearing the quality there.. meh. Cheaper to use `say`.

It'd be tolerable to hear a voice-interface with this, but it'd be maddening to try to listen to a book this way.

<comment><USER12> Check the license on 'say' before you use it commercially. There are restrictions.

<comment><USER13> Do you have a reference to the restrictions of what is prodced by "say"? Just because a tool may be GPL does not mean that its product need be (c.f. gcc)

<comment><USER12> From Page 2 of [http://images.apple.com/legal/sla/docs/macOS1012.pdf](http://images.apple.com/legal/sla/docs/macOS1012.pdf) :

> F. Voices. Subject to the terms and conditions of this License, you may use > the system voices included in the Apple Software ("System Voices") (i) while > running the Apple Software and (ii) to create your own original content and > projects for your personal, non-commercial use. No other use of the System > Voices is permitted by this License, including but not limited to the use, > reproduction, display, performance, recording, publishing or redistribution > of any of the System Voices in a profit, non-profit, public sharing or > commercial context.

Which truly sucks, because they don't even give you the option to pay for such use.

</comment></comment></comment></comment></comment><comment><USER14> I tried a few random sentences and some articles paragraphs with both Vitória and Ricardo (Brazilian Portuguese voices) and Ricardo did pretty well. I was impressed, really. Vitória on the other hand was not much better (as in "fluent", with rhythm and right intonation) than other available female voices out there for pt_BR.

EDIT: oh, I had no idea they have used Ivona

</comment><comment><USER15> Did they use ivona for this? Probably. Ivona Amy is awesome1

<comment><USER16> Almost sure about that they used ivona. Even name suggest the location of their office Polly -> Poland.

<comment><USER17> That'd be quite witty of them. Polly would normally map to being a parrot, repeating whatever was told to it.

</comment></comment></comment><comment><USER18> This sounds better than OSX text-to-speech for audiobook purposes, but the 1500 character limit per API call is annoying. Instead of sending the ebook text in full, I have to split by paragraph and (occasionally) sentence and then stitch everything back together with manually inserted pauses, making the audio a bit uneven.

</comment><comment><USER19> I wonder why they pulled the Ivona text2speech android app. I'm still happily using it. It's quite comfortable to listen to articles in pocket while on the train (and to keep listening while changing trains).

edit: ah it was just the german version that is not available any more, english one seems to be still the store: [https://play.google.com/store/apps/details?id=com.ivona.tts](https://play.google.com/store/apps/details?id=com.ivona.tts)

<comment><USER20> In the US I get "Sorry! This content is not available in your country yet." Interesting.

</comment></comment><comment><USER21> Does anyone know if NPR recently used this (or something similar) recently, on a story? I recall listening to a story in my car (hardly paying attention) and the person narrating the story, sounded unusual. I thought it is probably computer generated but I couldn't tell for sure. I guess the general public better get ready to tell the difference?

</comment><comment><USER22> Just me, or do the foreign voices sound much more realistic than the English speaking ones do? It could be the fact that I am not a native speaker of Icelandic, French etc. so perhaps to a native speaker, it may still seem robotic and sterile, but to me, the inflections and cadence sounds much more natural in the non English synthetic speech.

<comment><USER23> The French sounds a bit flat to me but I could easily mistake it for a somewhat bored human reading in mostly a monotone. But I certainly don't know French well enough to be sensitive to unnatural pauses or odd inflections.

It really is quite good--even if I really wouldn't want to read an entire book read this way or would mistake it for a human. It definitely gets me thinking about ways to use this service.

</comment></comment><comment><USER24> Surprised that Icelandic is being offered. As a native Icelandic speaker; to me it sounds about as good as can be expected with such a service. Isochrony (had to search the dictionary for that one) is a bit off but expected based on the context of phrases / words used to create the samples.

</comment><comment><USER25> I wonder if they support speech marks like Ivona, for allowing synchronization of text with audio, useful for text highlighting.

</comment><comment><USER5> The link to the Polly service console is broken. Polly doesn't even show up in the list of services on my AWS account.

<comment><USER26> Same. I'm sure this will roll out to us all in the coming hours.

</comment></comment><comment><USER27> Hope someone can post an audio clip for those of us lacking an account, curious to see how this sounds!

<comment><USER28> Scroll down a bit here and you'll ten different example voices: [https://aws.amazon.com/polly/](https://aws.amazon.com/polly/)

English male sounds surprisingly bad. English female is better.

<comment><USER5> That's pretty common among TTS services and engines. Most people want a female voice for their personal assistant/ebook reader/whatever, so the male voices don't seem to get as much tuning. As someone who happens to prefer a male voice on my apps, it's a little frustrating.

<comment><USER23> I don't know how much is tuning and how much is personal preference but I plugged in some different texts and I'd probably default to Amy (English, British).

</comment></comment></comment></comment><comment><USER29> I need the inverse of this is anyone selling that?

<comment><USER30> I don't know about Amazon, but Google does have Cloud Speech API; seems to be what you're looking for:

[https://cloud.google.com/speech/](https://cloud.google.com/speech/)

</comment></comment><comment><USER31> Does aws offer a speech recognition service too?

<comment><USER32> [https://aws.amazon.com/lex/](https://aws.amazon.com/lex/)

</comment></comment><comment><USER33> seems like a great opportunity for a tool to aide in learning pronunciation of foreign languages

</comment><comment><USER34> There's already a well known .NET library called Polly that's under the purview of the .NET Foundation. See [http://www.thepollyproject.org/](http://www.thepollyproject.org/)

This could get a bit confusing for some folks.</comment>


The Inventor of the Navy's 'UFO Patents' - <AUTHOR> https://www.thedrive.com/the-war-zone/31798/the-secretive-inventor-of-the-navys-bizarre-ufo-patents-finally-talks <comment><USER2> The problem I have in this, is that history is littered with things which without hindsight were crazy-batshit-ideas, and in a world of IPR and patents, definitely do get flagged as wierd. But.. then turn out to be useful.

Liquid metal refrigerators using electromagnetics to send the fluid around instead of just pumping ammonia? Thats .. crazy. But also, What Szilard and Einstein patented: safer by far, no moving parts in the working refrigerant fluid.

Directed beam weapons: notoriously the 'kill a goat' test for the BRL and Navy tired of loony inventors, but actually the ground work of Radar and like activity according to Robert Buderi (yes, this is a gloss, but there are linkages. The forces people _assumed_ RF beams were weapons, not detection systems)

Infra-Red for detection of the enemy. No more stupid than what they had, which is sound, giant sounding dishes to hear bombers. Turns out its harder to do IR than RF, but didn't stop Lord Cherwell obsessing about it, to the detriment of other science initiatives, but _NOW_ IR is a stable of all kinds of things.

These UFO patents may contain ideas which make sense in limited fields, or huge fields, or no fields.

(obviously, if they are based on perpetual motion flawed physics it tends to no fields)

<comment><USER3> In all of those cases the inventions sounded crazy And no one had really tried it before. A lot of smart people have been working on plasma physics with the goal of controlled fusion for 70 years. HTS research has been ongoing for nearly as long. Suddenly one guy who speaks like a crackpot has discovered things no one else has thought of? Occam's Razor.

<comment><USER4> The fusion tractor's control system needs far more EM signal processing and optics than we understood util recently.

<comment><USER3> You don't really need a serious amount of computation even for tokamak feedback systems. The computers of the 90s are adequate. Most other confinement machines (magnetic or otherwise) don't even need feedback. It's just bog standard industrial automation/control.

We've been on the ball for optics for a long time now. Where computation really comes in handy is in simulation and optimization. Plasma physics is still a very unfinished field and computation is a very valuable tool in speeding up the theory <-> experiment loop.

</comment></comment></comment></comment><comment><USER5> I'd really love some world changing breakthrough technology now. I really would. But I don't really understand this stuff (not that I'm qualified). I guess you can actually patent a perpetual motion machine, so the fact that it is a patent, doesn't seem to require that it be real.

I can't help but think back to the 80's SDI "Star Wars" programs. We said that we could do a lot of things that we couldn't, and that made the Russians crazy.

Now I'm not prone to conspiracy theories, but could it be possible this is a misinformation campaign?

It's interesting the "new IEEE paper" referenced in the paper only has the one author and no coauthors. I wonder who (if anyone) peer reviewed this paper? Also in the views, interestingly it's only had 40 views (not sure if this is paper views, or not, it says PDF and HTML views). Sadly I don't have access to read it!

[https://ieeexplore.ieee.org/abstract/document/8871349](https://ieeexplore.ieee.org/abstract/document/8871349)

<comment><USER6> "I guess you can actually patent a perpetual motion machine"

No, you can't because it violates fundamental principles of scientific laws.

<comment><USER5> Not only can you, but many people have:

[https://en.wikipedia.org/wiki/Perpetual_motion#Patents](https://en.wikipedia.org/wiki/Perpetual_motion#Patents)

<comment><USER7> From that what that link says, it sounds like you _could_ but _now cannot_ patent perpetual motion devices, since those applications are now rejected in America and UK. Perhaps you can patent them elsewhere though.

<comment><USER8> IIRC they are not rejected but you have to demonstrate the invention with a physical implementation. Of course this proves nothing but it does reduce the amount of paperwork.

There is legitimate research going on into reversing the casimir effect but the narrative they present is one of tribology rather than power generation.

</comment></comment></comment></comment></comment><comment><USER9> I would love to be wrong because this tech is very interesting, but I feel like I have developed a pretty good bullshit detector in my time online and quotes such as "VES being the Fifth State of Matter (Fifth Essence - Quintessence)" stick out to me as being discrediting.

<comment><USER6> Honestly, I have lost track of state of matters. How many are there? 3? s,l,g? Plasma? Bode Einstein Condensate? I vaguely remember at least three more.

<comment><USER10> Apparently in physics, there is less talk about states than about phases [1]. There are four fundamental states basically all matter can be in: solid, liquid, gas, plasma, but then you can get philosophical about what constitutes a state. Is a superfluid a liquid? I think there is a stronger case for Bose- Einstein condensate to be a separate state but one could argue otherwise. Crystalline vs amorphous solids could easily be argued as being different states etc...

Really, phases are more clearly defined, but more numerous, and change from one material to another.

And then you are left with the task of defining colloids, gels, aerosols...

[1] [https://en.wikipedia.org/wiki/Phase_(matter)](https://en.wikipedia.org/wiki/Phase_\(matter\))

</comment></comment></comment><comment><USER11> I like the part where he talks about Quintessence as if it's a valid scientific concept... not in terms of a hypothetical form of dark energy, but in the original sense that it's the "quinta essentia" or "fifth element", IE Aether.

His emails read like a word salad mix of high energy science and medieval alchemy... very similar to a lot of the "free energy" crackpots on youtube.

</comment><comment><USER12> I feel like I'm still reading something from the geocities archive.

</comment><comment><USER13> I continue to believe this is today's equivalent of "red mercury": crazy pseudoscience given the imprimatur of the U.S. military to distract and confuse adversaries.

<comment><USER14> It seems unlikely any serious adversary would be taken in by this.

I think it's more likely a case of gross managerial incompetence where superiors were taken in by a crackpot making claims far outside of his and their ability to evaluate.

</comment></comment><comment><USER15> This quote from another article on the source website is interesting:

"Craft Using An Inertial Mass Reduction Device." While all are pretty outlandish-sounding, the latter is the one that the Chief Technical Officer of the Naval Aviation Enterprise personally vouched for in a letter to the USPTO, claiming the Chinese are already developing similar capabilities.

...

"That being said, the unorthodox circumstances surrounding the approval of this patent have us wondering why the Chief Technology Officer of the U.S. Naval Aviation Enterprise, Dr. James Sheehy, personally vouched for the legitimacy of this beyond-revolutionary aerospace technology in the Navy's appeal to the USPTO. Sheehy assured the patent examiner in charge of this application that the aircraft propulsion method described in the patent is indeed possible or will be soon based on experiments and tests NAWCAD has already conducted. "

<comment><USER16> > the aircraft propulsion method described in the patent is indeed possible

from that patent - they describe there spinning the 2m diameter disk at 30000rpm (ie. 3km/s edge speed):

"... we obtain an energy flux value of 10e33 W/m2. This exceptionally high power intensity induces a pair production avalanche, thereby ensuring complete polarization of the local vacuum state."

i believe it - 10e33 W/m2 can do a lot (it is total power output of a million of Suns concentrated into 1m2), and such EM field would interact strongly not only with the Earth magnetic field, it will do it with just sheer vacuum as well (that is the point of their patent is that vacuum isn't really a full vacuum according to QM).

So everything seems ok from the pure math EM/QM formula POV. There are i think only minor pesky practical details - like the material able to withstand 30000rpm 3km/s rotation while under the 10e33 W/m2 EM flux (the flux which would tear apart atoms and may be even protons/neutrons) and a compact energy source doing all that while fitting into the 2m diameter disk.

</comment></comment><comment><USER17> As a slight counterpoint (I haven't looked into the claims of the patents too much): There is the well known Kerr-Newman solution of a rotating, charged black hole. It is well known that a relativistic rotating charged disk approximates in the limit of (v = c) the Kerr-Newman solution with (B = 0): [https://arxiv.org/pdf/gr-qc/0410109.pdf](https://arxiv.org/pdf/gr- qc/0410109.pdf). However the total field energy of such a rotating disk would be infinite, this is one of these examples in physics, where you run into pathologies. As is remarked in the paper those might be removed by a quantum treatment. For v < c the field energy is finite, which is in any case the only realisable regime.

</comment><comment><USER18> Trying to think if the DoD has any good reasons to encourage conspiracy theorists? Besides the obvious US has mystic weapons angle.

<comment><USER12> because some of them are conspiracy theorists? It would seem improbable that Michael Flynn is alone in that.

In any case, I think this is most likely due to incompetence. Whether a few of this guy's bosses are conspiracy theorists or not, they obviously aren't qualified to evaluate his work and see that he's a crackpot. It wouldn't be the first time, with things like MkUltra and that telepathy crap.

</comment></comment><comment><USER19> Wait a second. I thought you couldn't patent an idea that couldn't be demonstrated. For example, you can't patent the concept of faster than light travel in the hopes that one day, if someone does figure HOW to do it, you hold the patent. It's just absurd and that's what this all sounds like.

</comment><comment><USER20> You don't patent these things without expecting questions... Either they're really close to produce something that the public could replicate - hence the patenting, or they're miles away from anything realistic but patenting like crazy to remain 'relevant'.

</comment><comment><USER21> I know, you guys do not understand, it is "Turbo Encabulator" [https://www.youtube.com/watch?v=rLDgQg6bq7o](https://www.youtube.com/watch?v=rLDgQg6bq7o)

LOL

</comment><comment><USER22> AIUI, viable room temperature superconductors are an existential threat to the coal & gas industries.

Worse / better yet, they'd massively disrupt the existing geopolitical power and wealth distribution.

<comment><USER23> Wasn't there some airplane crashes that had engineers on the flight that worked for Freescale or some other company in the superconductor market? Funny how those stories just faded away with few questions about how the airliner crashed. I am not trying to make a conspiracy theory, but they should have taken separate flights.

edit: Typo and clarification

<comment><USER24> Snopes doesn't indicate this is likely to be true. [https://www.snopes.com/fact-check/mh370-patent- disappearance...](https://www.snopes.com/fact-check/mh370-patent- disappearance/)

<comment><USER25> Where's the Snopes like site Snoping Snopes?

</comment></comment></comment></comment><comment><USER21> Maybe just NSA and NAVY covert, keeping Chinese scientist busy wasting their time with nonsense science ?!

<comment><USER3> Some in the US seem to be keeping their mentally ill off the streets by paying them to make nonsense secret parents.</comment></comment>


Ask HN: What Are the Best Podcasts about Computer Science and Programming? - <AUTHOR> <comment><USER2> _The Indian Startup Show_. I don't know if I's allowed to link it. I'm from Bangladesh, but I listen many Indian shows and watch Mexican soap operas through VPN.

<comment><USER3> [http://www.indianstartupshow.com/](http://www.indianstartupshow.com/)

</comment></comment><comment><USER4> SimpleProgrammer website just had a poll on this - has a list of most languages and programmer related stuff. Worth a look

<comment><USER3> [https://simpleprogrammer.com/2017/01/17/winners-2016-softwar...](https://simpleprogrammer.com/2017/01/17/winners-2016-software- developer-podcast-awards/)

</comment></comment><comment><USER5> "Software Engineering Daily" is my favorite.

<comment><USER3> [https://softwareengineeringdaily.com/](https://softwareengineeringdaily.com/)</comment></comment>


Introducing Cairo GL ES v3 - <AUTHOR> https://blogs.s-osg.org/introducing-cairo-gl-es-v3/ <comment><USER2> It doesn't look like this is actually usable...

> The first step, which has landed in Cairo's trunk, simply detects if GL ES > 3.0 is available; if so, it creates a surface that's able to talk with the > GPU with this version of the protocol. Additional coding to leverage the new > functionality will be introduced later as follow-on work.

I would really love a cross-platform, hardware accelerated 2D API though. Right now the web's Canvas API is actually the best solution to this, which is really annoying because you shouldn't need to depend on the entire browser stack just for an easy way to draw a triangle to the screen. If accelerated Cairo could be plug-and-play with SDL (like in [https://www.cairographics.org/SDL/](https://www.cairographics.org/SDL/)) it'd be amazing.</comment>


If starting a pos company, what credit card processor would you go with - <AUTHOR>

Would appreciate any device on which credit card processor would go best with a POS. Particularly for low cost credit transactions, doesnt make sense to pay a $0.30 transaction fee for a dollar sale <comment><USER2> Without knowing what market you are targeting with the POS, that is an almost impossible question to answer. What types of customers will be using your system, what is the average charge, what countries will you be targeting are also a good starting point. Also, will you be selling to companies that have pre-established POS systems and credit card processing capabilities?

Your best bet may be to develop a processor-agnostic POS system, meaning that your system will work with most major processors. Otherwise you will be selling two solutions instead of one. The first solution will be the POS system itself, but the most difficult sale will be getting an established company to switch credit card processors to utilize your system. Unless you can offer them some financial incentive to switch you will be the underdog from the starting gate.

Also, since every business is different, having a one-size-fits-all credit card processor is impossible. Different volume levels, monthly charge volume, types of customers, types of business, and other risk factors will all directly influence the rates a processor will give your customer.</comment>


/r/Bitcoins inside job - <AUTHOR> https://np.reddit.com/r/btc/comments/7eil12/evidence_that_the_mods_of_rbitcoin_may_have_been/ <comment><AUTHOR> "After the massive amount of research we put into this, we believe that at least one moderator of /r/Bitcoin must have been either aware of the bot's plans (and allowed it to place blame on others), or have executed the attack themselves. This is most likely the moderator who immediately approved the [CU-1] comment. Other moderators may or may not have been involved. Meaning, yes, we believe that a moderator of /r/Bitcoin either directed or was complicit in the hacking of many of their own Bitcoin Reddit user accounts."</comment>


This Time Is Different Part I: What Bitcoin Isn't - <AUTHOR> https://medium.com/@markjeftovic/this-time-is-different-part-i-what-bitcoin-isnt-eb9f645239b1 <comment><USER2> So what is happening with Bitcoin isn't like tulipmania because tulipmania was not what it has been portrayed as. I don't know where that leaves the relationship between Bitcoin and tulips, but it does not address the claim that what is happening to the price of Bitcoin is a speculative bubble.</comment>


Amazon Offering Cremation Online, Who'd Have Thought? - <AUTHOR> http://www.techieinsider.com/news/13353 <comment><USER2> Interesting idea, but morbid</comment>


Zelda Ocarina Controlled Home Automation - <AUTHOR> https://www.youtube.com/watch?v=glZnkpIDWSE&feature=youtu.be <comment><USER2> How do I recognize tunes/sounds on raspberry pi like his device did?

<comment><AUTHOR> I just found this, but it looks like he documents projects to his patreon crowd: [https://www.patreon.com/sufficientlyadvanced](https://www.patreon.com/sufficientlyadvanced)</comment></comment>


Surrogate offered $10,000 to abort baby - <AUTHOR> http://edition.cnn.com/2013/03/04/health/surrogacy-kelley-legal-battle/index.html

<comment><AUTHOR> Raises a couple of ineresting Questions about the value of life, any life. And what authority we have(if any) to pass judgement on unborn babies as to whether their lives are 'un-livable'.</comment>


SilkRoad Closes $16 Million in Growth Financing Led by Foundation Capital - <AUTHOR> http://www.silkroad.com/Company/News-and-Media/Press_Releases/2013/08/SilkRoad-Closes-16-Million-in-Growth-Financing.html

<comment><USER2> First reaction was "wow, that is a ballsy move." Then realized it was for some _other_ silkroad and not the Craigslist for Meth & blow on Tor.

<comment> o0-0o Beat me to it...

</comment></comment><comment><AUTHOR> This is so gonna mess up our entity recognition at trending.io.

</comment><comment><USER3> Lol, up vote for the prank!</comment>


Rapidoid – No-Bullshit Web Framework for Java - <AUTHOR> http://www.rapidoid.org/ <comment><USER2> Not that speed matters a lot, but it seems they managed to create a new server that is nearly as fast as the fastest C++ server on the techempower benchmarks ([https://www.techempower.com/benchmarks/#section=data-r11&hw=...](https://www.techempower.com/benchmarks/#section=data-r11&hw=peak&test=plaintext)):

      *The low-level HTTP API provides access to the extremely fast Rapidoid HTTP
      server implemented from scratch on top of Java NIO.*

Thats quite an achievement, considering that Netty is very well optimized. Maybe the off-heap output buffer gives it that edge?

<comment><USER3> Hi, I am the author of Rapidoid, thanks!

The performance optimization is based on: \- using off-heap input and output buffers, \- minimizing the number of objects that are created when parsing the input and generating the output, \- using object pools to reuse the objects that must be created, \- using thread-local helper data structures on the I/O threads to avoid synchronization and object instantiation.

<comment><USER4> What happens when you have a long database query running? Is it async (which is a bit impossible with JDBC) but does it block one of the threads in worker pool?

</comment></comment></comment><comment><USER5> Neat!

Rapidoid reminds me a little bit the Spark Framework (not Apache Spark, very unlucky name, though) which I use for fast prototyping and services.

[http://sparkjava.com/](http://sparkjava.com/)

<comment><USER6> Also :

[http://jooby.org/](http://jooby.org/)

[http://www.ninjaframework.org/](http://www.ninjaframework.org/)

But the leader of the recent Java web frameworks really seem to be Vert.x ( [http://vertx.io/](http://vertx.io/) ) which I have started to use recently and like a lot so far.

<comment><USER7> Which is not that surprising since Vert.x is more than just a web framework. It also let's you build distributed applications and to scale your web app horizontally.

</comment></comment></comment><comment><USER8> This looks awesome! I used to use Spark for quick Java web apps, but I will (probably) try Rapidoid next time. That said, I have been using mostly Sinatra (Ruby) and Yesod (Haskell) recently but Rapidoid looks like a winner for Java- land.

I am surprised that I hadn't heard of Rapidoid before. +1 to HN

</comment><comment><USER9> Ha, I read "Javascript" at first. I guess my brain has a pretty strong pattern for "New web framework for X" at this point

</comment><comment><USER10> On another note, JAX-RS (a Java API for RESTful API's) is also fairly no- bullshit. It is also mature by now, and is supported by about a dozen implementations, including Jersey, WebLogic and JBoss.

</comment><comment><USER11> Too bad it doesn't have swagger integration (yet).

Love the easy, clean API - it's great for a reasonably sized project.

<comment><USER3> Thanks, I created an issue for Swagger integration: [https://github.com/rapidoid/rapidoid/issues/39](https://github.com/rapidoid/rapidoid/issues/39)

</comment></comment><comment><USER12> Would be interesting to try it in Scala

</comment><comment><USER13> Looks nice, reminds me of Jersey with the annotations but seems to offer more functionality. Good work!

<comment><USER3> Thanks! :)

</comment></comment><comment><USER4> The performance and elegance of this is breathtaking but I couldn't find if it has hot reloading built in.

If you have to recompile every time you change something, you're going to have a baaad time.

<comment><USER3> Hot reloading is not currently available, but it is almost finished. I added [https://github.com/rapidoid/rapidoid/issues/38](https://github.com/rapidoid/rapidoid/issues/38)

</comment></comment><comment><USER14> Interesting framework! looking for a side project just to try it.

Github link [https://github.com/rapidoid/rapidoid](https://github.com/rapidoid/rapidoid)

<comment><USER3> Thanks, Fabio! :)

</comment></comment><comment><USER15> Excellent work. Author truly deserves a lot of credit.

<comment><USER3> Thanks a lot!

</comment></comment><comment><USER16> Looks cool. But how do you execute one of those one-liners?

<comment><USER3> Thanks! You can try adding the one-liners in your "main" method. (You will need Java 8 and rapidoid-http-fast added as dependency).

<comment><USER16> Great - Got it to work. This should be documented on your site.

You also forgot to mention what I need to import in order to have the "On" object.

Maybe you can include something like this template on your getting started page.

      import org.rapidoid.http.fast.*;
      // wget https://repo.maven.apache.org/maven2/org/rapidoid/rapidoid-http-fast/5.0.7/rapidoid-http-fast-5.0.7.jar
      public class App
      {
        public static void main (String[] args)
        {
          On.get ("/size").json ("msg", msg -> msg.length ());
        }
      }

Also needed would be a sample pom.xml file. I had a problem with java compiler version being older and unable to complie lambdas.

My sample pom.xml (feel free to use it if you like) is:

      <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <groupId>com.microservices.app</groupId>
        <artifactId>rest-app</artifactId>
        <packaging>jar</packaging>
        <version>1.0-SNAPSHOT</version>
        <name>rest-app</name>
        <url>http://maven.apache.org</url>
        <properties>
          <java.version>1.8</java.version>
          <maven.compiler.source>1.8</maven.compiler.source>
          <maven.compiler.target>1.8</maven.compiler.target>
        </properties>
        <build>
          <plugins>
            <plugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-assembly-plugin</artifactId>
              <version>2.6</version>
              <configuration>
                <descriptorRefs>
                  <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
              </configuration>
              <executions>
                <execution>
                  <id>assemble-all</id>
                  <phase>package</phase>
                  <goals>
                    <goal>single</goal>
                  </goals>
                </execution>
              </executions>
            </plugin>
          </plugins>
        </build>
        <dependencies>
          <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
          </dependency>
          <dependency>
            <groupId>org.rapidoid</groupId>
            <artifactId>rapidoid-web</artifactId>
            <version>5.0.5</version>
          </dependency>
        </dependencies>
      </project>

Then I can run the test service using:

      java -cp target/rest-app-1.0-SNAPSHOT-jar-with-dependencies.jar App

<comment><USER3> Many thanks for this detailed feedback and example.

I totally agree a tutorial like this is needed, and I am going to add such documentation soon...

</comment></comment></comment></comment><comment><USER17> An excellent piece. The only problem is that it is now 2015, and everybody's moving to Websocket-based backends. Without WS support, new web frameworks are quite doomed.

<comment><USER18> Should you use WS even if you don't need to push data to the client in real- time?

<comment><USER19> I don't see any negative aspects of exposing the same REST API through WebSockets internally. Public API (if exists) doesn't need to change, private API loses the redundant transfer of headers and cookies.</comment></comment></comment>


Barclays' Finger Vein Scanner - <AUTHOR> http://www.businessinsider.com/barclays-finger-vein-scanner-2014-9

<comment><USER2> What a great idea, give violent and dangerous people a pecuniary interest in gaining control of a piece of your body.</comment>


Decoding the HTML 5 video codec debate - <AUTHOR> http://arstechnica.com/open-source/news/2009/07/decoding-the-html-5-video-codec-debate.ars <comment><USER2> "Some critics even contend that it's not possible to advance Theora without inevitably hitting a patent wall."

This article and the HTML 5 codec issue in general really illustrates the stifling effect that software patents are having on technical progress.

Are there any compelling reasons left to keep software patents around? It seems like they're doing way more harm than good.

</comment><comment><USER3> There is no debate. Hixie removed the relevant portions from the spec. There is now no required codec. Unless the landscape changes significantly, there will be no required video codec.

It's unfortunate, but it isn't the catastrophe that the article implies. The vendors that are going to support Theora out of the box are going to do so _anyway_ , and the vendors that are going to support h264 out of the box are going to do so _anyway_. Standardizing on either wouldn't have done nothing but dissociate the spec from reality.

<comment><USER4> _Standardizing on either wouldn't have done nothing but dissociate the spec from reality._

So now web designers have to deal with incompatibilities introduced in the last century, as well as ones introduced in yet-to-be published specs.

What is the point of standards if everyone is going to ignore them? The HTML5 committee could have saved a lot of time by not writing the spec and instead concentrating on a free reference implementation. (When browser vendors have to implement a spec on their own, they are going to cut corners to make things easy. If they can just cut-n-paste from a reference implementation, they will probably just use that.)

<comment><USER3> _What is the point of standards if everyone is going to ignore them?_

That's the point. That's _why_ that part was removed. If Theora had been mandated, Apple would have ignored it. If h264 had been mandated, Mozilla would have ignored it.

<comment><USER4> The end result is the same. You can't use <video> if you want it to work on all platforms.

<comment><USER3> Ah, but you can like so:

      <video>
          <source src="example-video.mp4" type="video/mp4" />
          <source src="example-video.ogv" type="video/ogg" />
      </video>

<comment> andrewl-hn I'm not really sure how it's going to work in Chrome, though. The article says they are going to support both codecs. As a result it's up to browser which video source to choose. It's interesting whether it will pick the first source or the 'preferred' one (presumably, mp4). Is it possible to set the source preference in HTML? Like:

      <video>
          <source src="example-video.mp4" type="video/mp4" />
          <source src="example-video.ogv" type="video/ogg" default/>
      </video>

or something similar?

<comment><USER5> The first supported <source /> is used (from the spec).

</comment></comment></comment></comment></comment></comment></comment><comment><USER6> An Apple representative has reached out to Xiph and their lawyers (SFLC) to make another attempt to address the (overblown, imho) submarine patent issue to the satisfaction of Apple's lawyers and so add support for Theora and Vorbis. So the story isn't over for Theora as the HTML5 video standard yet.

<http://lists.xiph.org/pipermail/theora/2009-July/002415.html>

It's worth pointing out that no-one has suggested H.264 as a recommended codec, not even Apple or Google who are both shipping H.264 support. Since it is patent encumbered it simply doesn't pass the first test for getting into a W3C standard. You'd be as well to suggest Flash or Silverlight be added to the spec, it would get shot down just as quick.

Apple apparently tried to get one of the less advanced H.264 profiles made royalty free, so it could go into the standard, but was getting pushback from some of the other patent holders in the MPEG-LA. That would have been interesting as it would have been a "first hit is free" kind of deal, where Safari/Quicktime would be able to support the higher levels of H.264 but Mozilla/Chromium/Linux wouldn't and Opera presumably would refuse to do so on principle.

</comment><comment><USER7> As a web developer I prefer the last option listed: allow video to use any and all codecs installed on the users computer.

BUT, expose this information to the server, so I know which video to serve. Add an Accept-Video-Codec and an Accept-Audio-Codec header, and that is all you need to do.

For extra points send some information on screen resolution in the headers, instead of making me use javascript for it.

The reason this is good is that _browers_ don't need to support anything. They just use the media libraries on the computer. If I want more codecs, I install them, I don't need to convice the browser to support them.

</comment><comment><USER4> The licensing fees for H.264 that go into effect next year should kill it off pretty quickly.

Of course, we should really just get rid of software patents.

<comment><USER8> Film/video post-production guy here. Agree about software patents but I'm not so sure about the licensing in this case. The thing is, h.264 really is very very good at what it does.

I don't think it's so bad to reward that with a license fee, and the patent administrators are benign dictators. There are lots of exceptions to allow startups to use it, there are sub-inflation caps on the fee increases, and the maximum license fee per hardware device is 20 cents. Online is a bit more complex but still very cheap. full terms here: <http://www.mpegla.com/avc/AVC_TermsSummary.pdf>

On principle, I lean towards a totally free software solution. But pragmatically, this is a very fair approach to administering a patent for a technology which delivers a lot of value, and and I think h.264 will persist for that reason.

<comment><USER9> Is it really so cheap? If so, it seems that it should be possible to create a mechanism which could cover these fees for open-source projects. Perhaps someone like Mozilla or Canonical or other open-source advocates could create a fund for such things? In an ideal world, we wouldn't have to pay licensing fees for this. But this seems a small price to pay for a standard video codec. Is there anything like this for .mp3 support?

<comment><USER10> The problem with patent licensing and open-source software is that patent license agreements are usually geared towards shipping physical items (such as DVD players, etc.) Commercial, proprietary software tries very much to behave like physical items (one single producer, building and shipping items to to customers) so patent terms like "20c per unit" work quite well.

Open-source, on the other hand, has a most unphysical habit of proliferating without the original creator's involvement. If Canonical promises to pay 20c per CD they ship, and 10% of those CDs are imaged and torrented and downloaded and burnt and re-imaged and re-shared all over the web, nobody knows how many "units" are out there, and there's no reasonable way Canonical (or Mozilla, or any other prospective licensee) can comply with any patent license more complicated than "do whatever you want".

</comment></comment></comment></comment><comment><USER11> Using "whatever codecs the user has installed" is the very non-solution that has _already been in place_ for over a decade by means of the <object>/<embed> tags. The result of that was eleventy hojillion attempts to make the ultimate codec, every single one a failure.

Even when <object> based video worked, the plugin architecture made it slow, unstable, unpredictable and generally a horrible user experience. The _only_ reason we have video at all today is because Flash provides it internally.

Any web video standard that fails to standardize the codec has made zero direct progress. However, it looks like the HTML5 attempt may have resulted in an acceptable defacto standard: a browser must support one or both of H.264 and/or Theora. Since the <video> tag makes it easy to provide both formats, I think this is a compromise that web developers will be able to live with.

</comment><comment><USER12> In my eyes there are two actual conclusions from all this:

1\. flash will remain the dominant video platform for the near future.

2\. This stalemate between theora and h.264 is a _huge_ win for chrome, the only browser that will support both.

</comment><comment><USER13> So doesn't Theora just win? Most Mac users seem to use Firefox, so Safari has a marketshare just a touch above Chrome. Still essentially a rounding error.

<comment><USER14> Even if everybody used Firefox, YouTube still wouldn't adopt Theora due to perceived bandwidth/quality issues.

<comment><USER15> could you elaborate here? what are the perceived band/quality issues you mean?

<comment><USER8> <http://en.wikipedia.org/wiki/Comparison_of_video_codecs> as a jumping-off point; <http://etill.net/projects/dirac_theora_evaluation/> for a flawed but quick analysis.

In brief, Theora is more open-ended (supporting up to terapixel resolutions!) but at the price of being far less optimized or well-supported for acquisition and delivery needs _today_. h.264, while processor-intensive and subject to long-term limitations delivers outstanding performance right now and is widely supported.

Also, Theora brands itself as ideal for web delivery with limited bandwidth leading to graceful rather than abrupt degradation, which is great, but of declining utility as bandwidth and reliability increase. It isn't pushed as a great choice for high-quality delivery, leading to a lack of awareness among content-providers who would rather use use h264 for everything from blu-ray to Youtube.

Now, that doesn't mean Theora has no future - as it matures it will become more desirable as a supported option, and the long-term architecture will help with that. Right now, however, it doesn't offer any significant technical benefit, like massively smaller compression or massively better image representation, compared to competitors. Making film and video is expensive and the patent licensing costs are such a tiny fraction of that cost that content providers and distributors really don't care. To them, Theora is a solution in search of a problem (indeed, many have never even heard of it). There is no economic incentive to deliver in this format, so they won't.

tl;dr programmers care about Theora, video people don't.</comment></comment></comment></comment>


A PostgreSQL response to Uber [pdf] - <AUTHOR> http://thebuild.com/presentations/uber-perconalive-2017.pdf <comment><USER2> Title should be changed to "A PostgreSQL consultancy's response to Uber [pdf]". Many people in this thread, including myself, assumed this was an official response by PostgreSQL.

<comment><USER3> thanks. comments like yours are why I always check the HN thread before deciding if something's worth reading.

</comment></comment><comment><USER4> The use of graphics in this PDF/slideshow was incredibly effective, more so than most articles I read.

The PDF lays out Uber's statements, and either lay it over a real-world analogy (a road on a sinkhole for database corruption) or lay it over a picture that primes their response (like a picture of apples and oranges when they plan to respond that Uber is comparing different features of mysql to postgresql).

The use of the elephant picture to give "elefacts" (sort of a parody on politifacts, where they evaluate the truth of uber's statements) is also great.

The images add humor and reinforce the content - great use of graphics!

<comment><USER5> Not to mention the elephant painted to look like a taxi :-)

</comment></comment><comment><USER6> This is missing one huge point of the [uber engineer post]([https://eng.uber.com/mysql-migration/](https://eng.uber.com/mysql- migration/)).

They did not switch from a postgres instance to put all their data in a mysql instance. They switched from a single postgres instance to shard their data across many mysql instances. This an entire reworking of the architecture that is completely ignored in this powerpoint.

<comment><USER7> Honestly I think Uber switching was more of a business decision as their employees had trouble figuring out how to properly use Postgres. Instagram definitely has different data needs, but is probably much bigger than Uber wrt data. They use Postgres successfully via Django no less!

[https://engineering.instagram.com/sharding-ids-at- instagram-...](https://engineering.instagram.com/sharding-ids-at- instagram-1cf5a71e5a5c)

<comment><USER8> As someone who participated in this transition, I don't think that was a part of it. The new database layer took quite a bit of instruction to use properly as well, and there were plenty of people misusing it.

</comment></comment></comment><comment><USER9> This comes across as a bit defensive and snarky. I'm not sure what it's hoping to achieve. The not so subtle message, reading between the lines, is that Uber engineers had bad experiences with postgres because they are morons. Well, maybe. But my main take away from that is that postgres is hard to use correctly, which if true is actually a good reason not to use it.

If only programmers could be polite to each other occasionally.

<comment><USER10> Having just read through the slide deck, I'm having a hard time coming to the same conclusion you do. Overall, I thought it was quite balanced, pointing out strengths and weaknesses of both MySQL and PostgreSQL. The author even started out with a slide with Inigo Montoya, "You insulted my elephant. Prepare to die", so he was clearly cognizant of the fact that this could be taken as purely a blind defense of PostgreSQL, and that is not the intent.

Would you mind taking the time to point out what phrases or slides gave you the impression that this was written from the position that "Uber engineers had bad experiences with postgres because they are morons"? I know that different people can get different impressions of the same material, so it would be helpful for me to understand better what gave you that impression.

There are a couple of comments like:

> _I assume the company the size of Uber can figure it out. C'mon_

> _But... c'mon. Uber?_

Both of these I think reflect the idea that it's likely Uber would have been able to continue to use Postgres if they were interested in fixing the issues they had with the system, rather than had additional, other motivations for doing so, the belief being that the Postgres-specific issues they list are likely soluble if they had wanted to put in the effort. They're a large enough organization that they should have had the resources to do so.

That doesn't mean that their decision to move off of Postgres for those other reasons wasn't the right thing to do: just that there's not enough information there for us to really understand the decision process. From a Postgres community standpoint, it's important to make sure that they have quality answers to the issues publicly raised by very visible companies such as Uber. Many people will read about Uber's experience with Postgres, and it makes sense for the Postgres community to be clear what can be done about them.

Your point about "postgres is hard to use correctly" I think is one of those things that it's hard to use a lot of the systems out there—not just Postgres—at the scale that Uber or some of the other large installations do. That's when you really become aware of where the stresses put on the systems start to show and what you need to be aware of to tune and set them up correctly for your use case.

Overall, I think 'gdulli's response ([https://news.ycombinator.com/item?id=14223170](https://news.ycombinator.com/item?id=14223170)) is largely on point.

Like I said above, if you'd point out which parts struck you as particularly unfair, I know I'd benefit from it to hear more from your perspective.

<comment><USER9> I found the use of shrug emojis in response to substantive points from the Uber paper pretty infuriating.

I didn't say that postgres is difficult to use. I said that the slides give that impression.

<comment><USER10> Interesting. I'm not a fan of emoji (or memes for that matter) in general, but I realize they're part of the tech culture now and try not to let them bother me too much.

The first shrug emoji was after the 9.2 data corruption bug. I took that one to mean "Yup. What are we going to do? There was a bug, and we fixed it as quickly as we correctly could. Incredibly regrettable, but that kind of stuff is going to happen." There are bugs in software. Knowing the Postgres developer community, they take correctness very seriously.

The second one is after the Uber quote which describes their tolerance for developer's holding open transactions and blocking I/O operations, which they do so from a position of inexperience because they're not database experts. I understood this one to mean "If you're going to use handle transactions in this manner, that's not something Postgres itself is going to be able to help you with."

The third was in response to the Uber quote regarding Uber application bugs which resulted in open idle connections. I took this shrug to mean that if this is an issue, it likely can (and should) be fixed in the Uber applications. It's not really a Postgres issue.

The fourth (and last) was in response to the lack of quantitative information regarding their Postgres issues (which makes honest, in-depth third-party investigation difficult), Uber's decision to go schema-less, and that MySQL is more tolerant of the bugs in Uber software. I took this one again to mean that there's little that Postgres itself is responsible for, or can do anything about here.

A question I always like to ask myself when someone has issues with something a third party is responsible for is what is a realistic and reasonable response from the third party. That often makes me realize that there's little they can be expected to do or are really responsible for, at least for some of the issues. For the most part, I think these shrugs reflect that.

If the shrug emojis were removed, would it be okay? Anything else?

<comment><USER9> The issue is that it's rude to quote someone and then respond with an emoji. If what they're saying is relevant then it merits a proper response. If it isn't relevant, or you don't have anything to say in response, then you shouldn't quote it in the first place.

You're welcome to come up with your own theories of what the emojis mean, but I don't see any point in doing so.

<comment><USER10> This is a slide deck from a presentation at Percona Live 2017.

[https://www.percona.com/live/17/sessions/postgresql- response...](https://www.percona.com/live/17/sessions/postgresql-response- uber)

We're missing everything that was said by the presenter. I would strongly suspect that the presenter said something about the slide.

<comment><USER9> Yeah that's a fair point. I'd suggest that's a reason to think carefully before posting a slide deck, though. If essential points are left off the slides entirely, then it may not be such a good idea to post the slides by themselves.

<comment><USER10> I think many people haven't had the issues you personally do with the presentation. That said, other comments in this thread make clear that you are not the only one to have read them as snarky. It's very useful to be charitable and give people the benefit of the doubt when reading their communication. I think there's a lot of useful information in the slide deck presented in a succinct way, and publishing them as-is is a useful and efficient way to do so.

I think with very little effort it's easy to interpret the shrugs as I did above, and there's little if any additional information that needs to be address along with the final shrug. I wouldn't have presented it this way, but I don't see any malevolence or negative intent on the part of the author.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER11> The response to "MySQL handles our devs' bugs better" is ¯\\_(ツ)_/¯ over and over, but, in my opinion, it's perfectly valid criticism. When writing a tool for real-world businesses to use, the path of least resistance needs to lead to bug-free code, and the tool must handle common buggy usage gracefully.

<comment><USER12> The path of least resistance should lead to quick and obvious failure rather than a false sense of security that the system is working. Careless development creates a price that has to be paid one way or another. You can't get something for nothing.

<comment><USER13> If you want your product to succeed it has to be easy to get to work. That means having insecure defaults etc. When a product is in production, people will go through hell to make it work a little better; when they're trying out a product they'll drop it at the slightest inconvenience.

<comment><USER14> Some people work that way. Other people do a more in-depth evaluation. The first group tends to end up with MySQL, the second with PostgreSQL. I'm painting with a broad brush here, there are situations where it might make more sense to use MySQL.

It would be hard to argue that PostgreSQL is not successful. MySQL has a larger market share, but the PostgreSQL project is alive and thriving.

</comment></comment></comment></comment><comment><USER15> I think this is humorous, and, in a way, brutal. Keep in mind it's not an official document from Postgres but rather just a guy who is big on Postgres writing a funny, and yes, snarky response to Uber. He makes some decent points, if not about the technologies themselves, about people switching to something more or less equivalent for reasons that could easily be interpreted as more gut reactions than solid business and tech necessities.

To me, Uber acted as though someone bought a Honda and it had some mechanical issues (and no seat heat), so he went apeshit, drove it off a cliff, then bought a Toyota thinking he will never have that problem again.

</comment><comment><USER16> My personal experience dealing with Postgres people vs. MySQL people has always been oddly lopsided, with Postgres users seeming to be crazy defensive about their product and getting very offended about any perceived slight when compared with MySQL, and MySQL users generally shrugging their shoulders and saying "post what?"

One camp seems to be made up of perfectionists who spend a lot of time worrying about how things "should" be, and the other seems to consist of pragmatists who just want it to work.

I will leave it to the reader to decide which is which and which has more appeal to business decision makers.

</comment><comment><USER17> In case somebody missed there is another article from Uber about justifying MySQL -> Postgres move a while back.

[https://www.yumpu.com/en/document/view/53683323/migrating- ub...](https://www.yumpu.com/en/document/view/53683323/migrating-uber-from- mysql-to-postgresql)

</comment><comment><USER18> Really nice to see another side of Uber's issues. Mainly because since Uber is a huge company most people will read their article as the absolute truth.

</comment><comment><USER19> Is there a video of this presentation? Was this from pgconf 2017?

<comment><USER20> I saw it presented at Percona Live three days ago. As far as I am aware, there was no video.

</comment></comment><comment><USER21> I think this slideshow is doing the project a disservice. Mysql is definitely a "lesser" database, that seems to be widely known and accepted. It seems to be also very frustrating for the PostGres team that that is not the sole factor, but it isn't. For a shared database it's not even that high up there. This slideshow is bemoaning that Uber seems to find the design decisions of PostGres a problem. Really, they're fine decisions "just get a department to deal with them", is the message. And yes, that is very much the PostGres attitude.

The great thing about MySQL is that it generally just keeps working with incredibly small amounts of maintenance whereas PostGRESQL just constantly needs attention. This has always been my personal complaint. From vacuuming (yes I used PostGRESQL before autovacuum, and you can still fuck up autovacuum) to upgrades, everything is just fiddly fiddly fiddly.

The end result is that mysql, you start it, you run it, you do your normal OS upgrades and everything just kinda hums along. For years and years. PostGRESQL is like all enterprise solutions : you start it and run it and a month or so and it suddenly refuses to accept connections, or suddenly it starts using too much disk (e.g. misconfiguring autovacuum), or ... It has a bazillion things you need to configure and make cooperate and there's large procedures for everything you need do to. Every week some warning light goes all flashy and won't stop flashing until it made you press a few buttons where it was perfectly predictable which buttons needed to be pressed. It forces you to consider 2000 configuration options, rather than picking sensible defaults, instead asking.

But yes, you get something back for that. A bigger, better, more correct and far more featureful database. In many ways it starts having the issues of other large databases (e.g. the 3-page-and-totally-inscrutable SQL stored procedure functions).

This is very much a case of "pick your poison". But frankly, if you want your app to just run, like we all do, MySQL will serve you better. If your OCD can't deal with small imperfections, datatypes that fit only 99%, having values that your text mode SELECT in the database can't print ... if those bother you, stay away from MySQL. And of course the classic, if you have a "real database workload" (very heavy load with constant reads AND constant writes), yes you probably need PostGRESQL.

You could say Mysql is halfway between LevelDB and PostGres.

By the way, if you need a mobile database with zero maintenance, SQLite will serve you even better. It can't be shared with other applications and is not meant for database-behind-network approaches, but you'd be surprised how well it can work.

<comment><USER22> > I think this slideshow is doing the project a disservice.

I think you know, but I just want to emphasize: This is not the project's response, it's an individual's response.

</comment></comment><comment><USER23> This is fun, but here's the actual, less snarky, response from Postgres developers, as previously discussed: [https://news.ycombinator.com/item?id=12201353](https://news.ycombinator.com/item?id=12201353)

</comment><comment><USER24> The index issue and the memory used per connection I can understand but when they didn't even try to use one of the many logical replication systems that have been used a scale bigger than Uber, hello Marco at Skype, the argument against Postgres gets a bit confusing. Uber seemed to really understand some things with amazing depth and not understand others that are documented by others outside of Uber. I think some politics played a big part.

</comment><comment><USER25> I know PostgreSQL meant to defend themselves, but it just made the matter worse.

1) I didnt even know Uber switched database, now I know. I also know the reasons.

2) Comes across as unprofessional, you don't see Microsoft defending MSSQL this way. They let the users see it for themselves.

<comment><USER26> > I know PostgreSQL meant to defend themselves

[...]

> you don't see Microsoft defending MSSQL this way.

PostgreSQL Experts Inc. is a consultancy that specializes in PostgreSQL; they don't appear to be particularly linked to Postgres development organizationally (and none of their staff profiles highlight involvement in Postgres development). If this was the PostgreSQL Global Development Group, you'd be a bit more on point.

<comment><USER27> If its not PostgreSQL but instead a consultancy then the title should be changed to reflect that. The misunderstanding is likely to affect the comments (as above).

<comment><USER28> The title does already reflect that. The name of the consultancy is on the title page of the document.

</comment></comment></comment></comment><comment><USER27> I'm a little confused by the pdf. Is it implying that the program is opening and closing a connection for each query? Is that normal these days?

<comment><USER29> Some applications will indeed do that to guard against the server-side memory cost of thousands of postgres pool connections. It makes sense when queries are relatively rare.

This was the solution that we used at MX Logic in the early years, before we moved to pgbouncer and went back to long-lived stateless connection pools.

</comment></comment><comment><USER30> Facebook (TAO), Dropbox (Edgestore) also moved to a schema-less database design. I wonder how these large orgs manage versioning of their models...

<comment><USER31> You put a version key & number in the model blob metadata itself.

</comment></comment><comment><USER32> Love the shrug emoji

<comment><USER33> I think it is an emoticon, but I am not sure! Or are emoticons always sideways? Hmm...!

<comment><USER34> I always thought "emoticon" is the most generic word that includes everything from ":)" to the shrug to unicode emoji.

</comment></comment></comment><comment><USER35> The reason (and timing) for the somewhat snarky response is probably because Uber right now have a bit of a black mark against them PR wise.

</comment><comment><USER36> Meanwhile Amazon and AWS have essentially banned putting a relational database behind any publicly facing website or service.

<comment><USER37> While I don't doubt that they'll tell you that that was a scaling decision, it actually has more to do with an architectural decision that proved to be difficult to overcome once it's flaw became apparent.

They operated warehouses using a monolithic oracle database, one for each FC. They had hundreds of different services using the same database. Whenever one service wanted to do something new, they had to spend a massive amount of time running their proposed database change past every team on the database. I've seen a single column addition take 9 months and hundreds of engineer hours to get approved.

So once the warehouses got really big, sharding was the obvious answer but they couldn't make sharding work because they couldn't coordinate their way out of their mess they created. They couldn't scale because they engineered themselves into a corner that made it impossible to use normal best practices for scaling SQL databases.

NoSQL has an interesting lack of a feature that solves their problem. Because theyre not relational, they don't really work very well sharing data across services and teams, so they don't get into major coordination tangles on shared databases. Maybe that works for them, but it's more of an indictment of their engineering culture than it is a slight on SQL databases. And it's pretty punitive in a TSA kind of way: We fucked up once so none of you can have nice things anymore.

</comment></comment><comment><USER38> Can anybody explain about the buffer pools part?

<comment><USER39> Caching can happen in a number of places, with a variety of degrees of success. In psql, a lot of caching is deferred to the OS filesystem layer. In MySQL, apparently, they have a additional cache in the MySQL address space.

There's two sides to this. Generally speaking, an general purpose OS will use cache management algorithms that suck compared to what an application could do, because the application has more structured knowledge. In the case of a DB, it knows about indexes, and row sizes, and is less likely to evict half an index or row.

On the other hand, the OS is sort of the last authority. Varnish, in particular, argues that programmers should rely on the OS caching algorithms, because you have them whether or not you want them. A poor interaction between userspace and kernelspace caches can end up increasing I/O activity if kernel pages something to disk before the userspace does (varnish had a doc somewhere explaining this better, which I can no longer find). The penalty here though is context switching. A userspace cache is available in memory, whereas a filesystem / buffer cache will incur a context switch to retrieve the data from kernelspace to userspace.

Finally, both have a number of caches, so this is more about how much and what type of userspace caching.</comment></comment>


My Product Is Unexpectedly Being Used to Help People with Dementia - <AUTHOR> https://nanagram.co/blog/nanagram-for-dementia/ <comment><USER2> I signed up for this the last time it came up on HN. Although I've had trouble on my end with mailing addresses and uncooperative nursing homes, Alex at Nanagram has been absolutely fantastic and proactively helpful.

It's been a niche use-case for me - getting photos to the two grandparents that can't get on board with smart phones - but as far as it goes, it's a phenomenal product for that niche. It's definitely allowed me to keep grandparents involved with my newborn in a way that would otherwise not be nearly as convenient. The closest alternative would be to make a point of sending a snapfish order every few weeks; with NG, I just text a photo to them at the same time I'm texting my other relatives.

My only wish is that they could somehow foolproof their packaging to get past the front desk at nursing homes, but I don't know if that's possible. NH seem to just not be built for accepting mail for their residents.

It's a good service, run by good people.

<comment><AUTHOR> Thanks so much for the kind words. I'm working on some new packaging. Nursing homes tend to be pretty sensitive about HIPAA and mail. I had a dream to get NanaGram into nursing homes as a group activity, hammered on sales a while and put it on the back burner. I'll probably revisit it soon. The general idea is people would open their photos together, making for a way for residents and team members to get to know each other better. All of the photos would come in one box to avoid delivery issues.

All that said, I'm working on some new packaging and will reach out to you by email to get you hooked up in a beta so we can improve your delivery.

<comment><USER3> Add chocolate to the boxes ;-)

And a note: "take care of the grandmas/grandpas and also make sure these photos gets delivered to their rooms and there probably be another box next month."

I'm joking but I feel I'm not too far away from a useful idea.

<comment><USER4> It's a lovely idea, but with forethought into allergy concerns in medical facilities and shared homes (especially in international market), as well as maybe import/health code related stuff, I wouldn't sidetrack the original vision for it.

</comment></comment></comment></comment><comment><USER5> I really like this product. As others have said, Alex is excellent at customer service. He's taken my actual phone calls, and really helped out. He's even implemented some features that helped my sister contribute from Scotland (with no overseas SMS). I continue to recommend it constantly.

<comment><AUTHOR> Thank you! I love talking to customers on the phone. I subscribe to the idea of building a product or feature for one person. You kickstarted what eventually became an international email product. Now we've got customers delivering all over the place. Pretty soon I hope to start shipping worldwide. Thanks for sharing us with your friends.

<comment><USER6> Might it be cheaper/easier/more ecofriendly to print in the destination country?

(Which probably might not be possible for any country, but for example in Europe it might work pretty well. Many printers offer the services you'd need I think. Or just one printer per continent might also be ok.)

Although there might be other problems of course.

<comment><AUTHOR> We're doing that right now with most international destinations. We just don't have a Canadian printer. It's likely I'll start printing them here in the Boston area for Canadian users. The US and Canada offer super fair postage rates for first-class mail.

</comment></comment></comment></comment><comment><USER7> Thank you for a product that focuses on a real need for the elderly. It might seem like an inconsequential thing to some, but I'm sure this kind of thing can considerably improve the quality of life for older people.

My mom has always embraced technology, but as she gets older, I can see her struggling with increasing anxiety using her computer and iPad, etc. I can imagine some day this being the perfect thing for her.

It's so easy to forget our older loved ones, and it's easy for the elderly to slip through the cracks of our society. I'd love to see more companies out there solving problems like this that improve the quality of life for the elderly.

Bravo for a product that brings joy and makes the world a little nicer place.

<comment><AUTHOR> Thanks so much! Susan Pinker gave a fantastic Ted talk about this topic: [https://www.ted.com/talks/susan_pinker_the_secret_to_living_...](https://www.ted.com/talks/susan_pinker_the_secret_to_living_longer_may_be_your_social_life)

The #1 factor to leading a long and happy life is the frequency of your social interactions, both with close friends and family and acquaintances. I'm certainly getting reports of people talking to their grandparents more since they started sending photos and it warms my heart.

There's quite a bit happening in this space which has recently been coined by some as "elder tech." Alexis Ohanian and Garry Tan's fund Initialized are investing in the space in startups like [https://www.joinpapa.com](https://www.joinpapa.com).

</comment></comment><comment><USER8> On a tangent, the BBC has a site to assist with "reminisce therapy" using material from BBC archives.

[https://www.bbc.co.uk/rd/blog/2017-02-bbc-rem-arc- dementia-m...](https://www.bbc.co.uk/rd/blog/2017-02-bbc-rem-arc-dementia- memories-archive)

[https://remarc.bbcrewind.co.uk/index.html](https://remarc.bbcrewind.co.uk/index.html)

<comment><AUTHOR> Awesome, haven't seen this yet. Thanks. The UK seems to be leading the way in elder care. Last year, they appointed a "Ministry of Loneliness." [https://www.nytimes.com/2018/01/17/world/europe/uk- britain-l...](https://www.nytimes.com/2018/01/17/world/europe/uk-britain- loneliness.html)

</comment></comment><comment><USER9> Thumbs up everything about this product. I just started a side project that has minimal interface goals for a low(er) tech use case, and this is lovely.

<comment><AUTHOR> Nice! Best of luck with launching.

</comment></comment><comment><USER10> Good to see you ship to Canada too. I'm in Japan where Mixi has a service called [Nohana]([https://news.ycombinator.com/item?id=19966877](https://news.ycombinator.com/item?id=19966877)) that's similar (but an app), but looking forward to checking yours out, maybe with the help of my brothers back home. Nice work!

<comment><AUTHOR> Sweet! I haven't heard of Nohana yet, thanks for sharing. Japan seems like it would be a great place to expand to soon.

BTW, I'm hoping to drop the price for Canada in the next couple months!

</comment></comment><comment><USER11> @aacook this is awesome! I just showed it to my sister and we're going to sign up for my Grandma's birthday next month. One request: Snapchat is our native photo sharing app (and I assume that's true for many other millennials) any chance there's a way to send from snapchat in the works?

<comment><AUTHOR> Thank you! I've explored other platforms. One of the reasons I've been hesitant to rely too heavily on social tools is NanaGram is often used for photos that never make their way to social. That said, Whatsapp has an API but it's invite-only and I've had no luck getting in. It's too bad because it would be a perfect medium. Hopefully in time.

Snapchat would be a great fit. I looked it about a year ago and it wasn't feasible. I'll take a look again!

In the meantime, we do support email by giving you a unique NanaGram email address.

<comment><USER4> Making the UX on explaining/teaching the user how to add a custom email as a contact, or doing it for them, will be huge.

<comment><AUTHOR> Thanks! I had a step in the initial onboarding to let folks add their NanaGram recipient as a contact via a contact.vcf file. I user tested with 5-6 people and couldn't quite nail it. Had other priorities at the time and decided to back burner it. The concept of downloading a vcf file, opening it, etc is foreign to many people. Another challenge to nail was the copy around adding a contact record for the recipient, as many people were confused (I already have a contact for my Nana!) This kind of address book integration seems easier to do in a native app. Soon, I hope!

</comment></comment></comment></comment><comment><USER12> I also work on a product that's been unexpectedly beneficial for dementia, amount other things (Marco Polo). As a researcher, it's been a revelation about how often products are useful in ways we don't design for, and the inverse, how products designed for a purpose can end up having negative or even counterproductive effects. (Social Media might fall into both categories). This is a good argument for design and user research in general.

<comment><AUTHOR> Awesome! My wife and her family are crazy about your app. Her mom discovered an unknown half-sister through an Ancestry.com match. They used Marco Polo to get to know each other. My wife's mom also sends monthly printed photos via NanaGram.

</comment></comment><comment><USER13> Just sent this to my mom. I think your product looks really useful, joyful, well-priced, well-built and well-run. I think if you keep it up, you'll be really successful! I'm rooting for you!

<comment><AUTHOR> Nice! Thanks so much for the supportive words. There have been a few times were I've considered "giving up" (putting this on the back-burner to take on contract work and pay the bills) but I've been fortunate with things like this HN thread. I'm also lucky to have a crazy supportive wife and family.

</comment></comment><comment><USER14> Costco sends photos for free when you order from a computer. I regularly send a handful of photos to my older relatives and pay just 17¢ each. Print quality is much better than places like Walgreens, IMO.

<comment><AUTHOR> Nice, thanks for sharing! Do you have to be a member? It's free shipping with no order minimum?

NanaGram works best for people with siblings or cousins who want to send a curated pack of photos to their loved ones. The account owner can invite people to send in photos and everyone can tailor reminders (1 week, 3 days, 3 hours, etc from the monthly ship date).

The other nice thing is the interface, since most of the time there isn't one. We give you a unique phone number and all you have to do is text your photos to the number.

I'm hoping to release a couple low-priced solo-sender plans soon.

<comment><USER14> No minimum! I literally send 3 photos for the cost of a stamp. You do have to be a member, I think.

<comment><AUTHOR> That's pretty cool. Thanks for this. I tried to sign up but it won't let me through without a member number ([http://bit.ly/2YDIHaD](http://bit.ly/2YDIHaD)). Maybe Costco is able to do this using member fees to offset the costs.

I am offering a way for people to try us completely free right now. It's on the home page. You can also just text 3 photos to 617-622-5124.

I wonder if Costco ships internationally. Thanks again for the heads up.

<comment><USER14> Costco doesn't ship internationally. I used them to make the mugs for a Kickstarter once, and I had to pick up and separately mail all the international orders.

I appreciate your letting people try this for free! I would pay a little extra to get their good quality printing and matte option. Of course, the convenience you offer would also be great!

</comment></comment></comment></comment></comment><comment><USER15> Bah this was on my todo list for a while -- ended up subscribing today finally!

<comment><AUTHOR> So amped to have you on board.

</comment></comment><comment><USER16> It's a great idea and I wish I'd known last Christmas when I had to print and post 5-6 photos to 5 recipients with a total cost of ~£100. My hustle also costs something but it's not priced in.

Only one question if I may. How can I know for sure you delete the photos? Is the business GDPR compliant? If I am based in the EU, do my photos need to go to server in the US? I'd prefer if they didn't have my young daughter's pics...

<comment><AUTHOR> Thanks for these details. We take privacy extremely seriously. Most international folks use the email version of our product. In that case, they'd go from your mailbox to ours (Google Apps / Gmail) and then onto our server (Digital Ocean, NYC). We never use your images for marketing or promotion, unless in specific cases where we have your permission. For example, when people post reviews with their loved ones holding NanaGram prints. We don't get that many requests for deletion, but when we do, I run a full delete on your data.

</comment></comment><comment><USER17> Thank you, what a great idea! :)

<comment><AUTHOR> Thank you! I can't take credit for the idea. That goes to my brother Andy. He'd originally dubbed the prototype "Instagrandpa" but we thought Facebook might get upset and went with NanaGram.

<comment><USER18> Good for you, because that's a fantastic name.

<comment><AUTHOR> Thanks! I wrote a little bit more about the story around the name at [https://nanagram.co/blog/the-grandma-test](https://nanagram.co/blog/the- grandma-test)

</comment></comment></comment></comment><comment><USER19> Is an API on your roadmap?

<comment><AUTHOR> Not yet. What would you use it for? Alternatively, drop me an email via the button on the bottom right of the home page.

<comment><USER19> Mostly curious. I have an old photo sharing site and was wondering what kinds of integrations are possible.

</comment></comment></comment><comment><USER20> As someone who is dealing with a mother with actual dementia, the term "tool to fight dementia" is deeply misleading at best.

It's fine as a product, but it does nothing to "fight" dementia. It's a convenience and that's it.

"Fighting" implies that it has some therapeutic value that can stop or slow down the progression of the disease, and this does nothing. It's just an easy way to flip through pictures. After watching my mom go from a brilliant pharmacist to an incontinent, paranoid, angry stranger in the span of 6 years, I guarantee you there is absolutely nothing that flipping through a photobook will do that will do to fight dementia.

It's great for grandparents and older folks because it's familiar and convenient and easy to change. It's not a tool to fight dementia.

<comment><AUTHOR> I am truly sorry to hear about your mom's dementia progression. I can only imagine. Wishing you and your family strength.

A few of my customers have mentioned it's helping them. I observed first-hand that going through fresh photos seemed to help my grandma too. She had dementia, although hers didn't progress as far as your moms. Maybe the photos didn't help but instead it was the frequent interactions with her loved ones that did. Also, maybe products like NanaGram help in the early stages of the disease but not later on.

I'm not a psychologist and dementia is an extraordinarily complex disease. I'm most definitely not trying to mislead. I drafted a few different variations on the title and ended up going with this one to get the point across.

<comment><USER20> I appreciate what you said, and I don't assume bad intent.

However, I would urge you to be careful with the words that you choose, especially when it comes to a topic like this. I have no doubt that your product will make those with dementia happy and having actual tangible photos is easy for anyone to use. Seeing photos of loved ones or just photos in general even if they don't recognize the people anymore. Anyone will get happy looking at a picture of beautiful child. We have an iPad for my mom just for that purpose and my siblings will go through pics with my mom all the time. She no longer recognizes my wife or my son (she confuses my son with me now all the time, and she talks to the iPad thinking that she is communicating with the person on the screen). But no doubt seeing those pictures makes her happy in that moment.

But dementia is an extremely cruel disease, worse than any other because it robs people of their humanity over many years and leaves families with huge bills and extreme guilt.

Photos won't help. Exercise doesn't help. Neither will omega fatty acids, various other pills or diets, 40 Hz light therapy, etc. It will continue to progress until the person is only alive in the clinical sense, but will be nothing like what their family remembers. Photos make people laugh and smile, but that's not help in any sense more than watching a funny tv show would help.

<comment><AUTHOR> Thanks so much for all of your feedback. I won't take it lightly. Looks like HN edited the title. I edited mine too. I'll be thinking of your feedback when writing future posts.</comment></comment></comment></comment>


DIY Amps: A Roadmap for Beginners (2017) - <AUTHOR> https://audioprimate.blog/2017/06/17/diy-a-roadmap-for-beginners/ <comment><USER2> My favorite audio resource for those designing or evaluating audio amps and DACs is NwAvGuy's blog[0]. The blog posts explain what performance parameters matter, what don't, and evaluates the performance of various products and components.

Equally interesting is the mysterious story about the anonymous author himself [1]

[0] [http://nwavguy.blogspot.com/](http://nwavguy.blogspot.com/)

[1] [https://spectrum.ieee.org/tech-history/silicon- revolution/nw...](https://spectrum.ieee.org/tech-history/silicon- revolution/nwavguy-the-audio-genius-who-vanished.amp.html)

<comment><USER3> I have one Objective-2 amplifier right now on my desktop. Great fidelity, reliable and robust. It's the best DIY project I've ever done. Thanks NwAvGuy!

</comment></comment><comment><USER4> A neat hobby in the nostalgia sense but I'm convinced many audiophiles are misled in the idea of audio quality.

You can build something with a mathematically perfect decode and EQ using a raspberry pi. You want digital all the way to final amp stage.

For the amp stage (especially at low power headphone levels) the best amp option is a nice dedicated amp chip. For a few dollars and little external circuitry you can get a chip that will put out 10 watts into a sub ohm load with less than 1% THD. Class D too so it uses ~1/2 the power.

Good example, the old discontinued Sansa Clip, a $20 mp3 player the size of a tic tac box, has one of the best headphone amps tested. Combine it with rockbox firmware and you have a super practical headphone amp that will rival anything money can buy.

<comment><USER5> I'm curious how something like the headphone amps or what you mentioned compares to the headphone outputs on a high-end audio interface, e.g. the RME Fireface line or similar recording products.

<comment><USER6> I have a Fireface and never had only the slightest issue with the headphone outputs.

As somebody who understands quite a bit about analog circuits and has seen Firefaces from the inside I would definitly trust RME on that one, this thing is beautifully engineered

<comment><USER5> :) love my fireface

</comment></comment></comment></comment><comment><USER7> I've built a half dozen Fender Bassmans and a few Fender Super amps over the years. I thought the article would be about this kind of amp building, but evidently not many hacker news readers play blues harp through a tube amp.

Low tech tube amps are quite easy to build, although they cost a few hundred because the transformers, chassis and tubes can be pricey and the cabs and speakers aren't cheap. The results are great, though, and I'd say go for it if you are thinking about trying.

Get everything you need from Tubes and More dot com or eBay.

<comment><USER8> Are Bassman amps actually better at reproducing and projecting lower frequencies? I have a fender amp for my regular electric, and a bass amp for my bass guitar. I also have a baritone and wanted an amp for in between.

<comment><USER9> Originally the Bassman was a 50 watt amplifier with a pair of 6L6 tubes, this is enough power to allow a solid-body bass guitar to play cleanly only about as loud as a regular acoustic string bass.

For bass guitar, there was no need for reverb or tremolo so those tube effects were not included on Bassmans. 6-string guitarists sometimes found these Bassmans more gainful at maximum volume than the non-bass Fenders having equivalent power and tube complement. A single pair of 6L6 (about 50W) for guitar will be loud enough to keep up with an acoustic drum kit for lots of blues and soft rock, while bass guitar actually needs about 300W.

With a loud drum kit and a heavy-hitting hard rock acoustic drummer, then I naturally recommend a 100W fullstack for guitar and 400W for bass.

The circuitry of the Bassman is not designed for big differences in frequency coverage compared to the non-bass vintage Fenders. The Bassman was primarily a regular no-frills 50W head, and for actual bass use within its power level (like in studios) it achieved lower lows because of use with a closed-back cabinet.

<comment><USER8> Thanks for helping explain the name and history.

</comment></comment></comment></comment><comment><USER10> In South Africa almost all of our electronics are imported. Given the high amounts of unemployment, the technical recession, lack of secondary industries and manifacturing, the brain drain and scarcity of technical skills, etc., I would really like to see something like this develop into a viable business.

Of course after that it would not be DIY anymore, but I like the spirit of learning and productivity which at the same time would be refreshing to see it developed into a viable product.

If you buy a high end powered speaker or amp here, expect to pay 50% more that the price you see on Amazon. So, you basically have a 50% profit margin even if your cost is equal to the _sales_ (!) price in the US.

</comment><comment><USER11> Happy to see a couple of tube amps among the kit listings.

I've enjoyed building many, many tube amplifiers in the past two decades or so. Initially they were kits, later I did rolled my own point-to-point amps and later still laid out my own PCB's for some PCB-based tube amps.

While the high voltages might seem intimidating (safety-wise) I hope that doesn't keep people from pursuing this class of amplifiers. If you're smart about it, you'll be okay. And there is nothing like the sweet music of non- quantum sound amplification.

(When consider that my other hobby involves a table saw I'm beginning to wonder what might be behind some of my life choices…)

<comment> ur--whale The age old question: besides the obvious aesthetic attractiveness, is there really any kind of objective advantages to tube-based audio amps as opposed to solid-state semiconductor based ones?

<comment><USER12> In audio most objectivists believe that currently known measurements (frequency response, power handling abilities, THD, PSSR, other non linear distortions, noise floor, etc.) can 100% conclusively define subjective sound. But then on the flip side there are very reputable people (eg. Paul McGowan from PS audio) agree that we may not have figured out all measurements necessary to nail down subjective audio quality. It is upto the ears of the listeners and their exposure to super high end audio to decide whether that is true.

I fall in the camp that thinks we haven't fully figured out what conclusively decides subjective sound quality. It makes things much more interesting and open to more research to settle debates on solid state vs tube, sigma-delta vs r2r dacs, full range driver vs other speaker configurations, cables/interconnects/power-cords matter or not and things like that).

Some interesting links (I don't endorse what these guys are saying but find them VERY interesting):

About DACs: [http://www.streamplayer.io/v1/sharing?v=8Mn5PrnZV-k](http://www.streamplayer.io/v1/sharing?v=8Mn5PrnZV-k)

About whether audio power cables make a difference (Ask Paul from PS audio): [http://www.streamplayer.io/v1/sharing?v=8QuToO9JUfw](http://www.streamplayer.io/v1/sharing?v=8QuToO9JUfw)

<comment><USER13> This measurability nonsense is a red herring.

Think about it, the question can easily be answered by blind A/B testing using real listeners with varying aptitude for discerning any differences and the qualities.

Over the years people have tried and failed often to show much difference, when tests were done with proper controls and with scientific rigor.

To be fair I haven't read up on the subject recently so if there's anything current that shows otherwise I'd be glad to read a link to a paper from a credible source.

<comment><USER14> False.

Rigorous double blind a/b/c/d tests using real listeners has been performed, and the research has been published in peer reviewed journals since the 80's.

What has happened is that most of the audiophile community saw research as a threat to their revenue streams and actively FUD around it. And the audio engineering community has simply moved on.

Here is a talk that could be very informative. [https://www.youtube.com/watch?v=zrpUDuUtxPM](https://www.youtube.com/watch?v=zrpUDuUtxPM)

His book is worth a read as well.

<comment><USER13> What's one thing I said that was false?

I said studies have been done that failed to show any difference, that's absolutely true.

I said I was open to hearing about recent papers published showing otherwise, yet you've provided zero links to a peer reviewed paper. You offer a Youtube video? If it's a video about research can we just skip to a direct link to the science? Citation please?

I said it's not necessary to know if current testing equipment can detect differences, _to know if people can tell the difference_. True.

Where are the rigorous double blind studies, with full disclosure, conducted with no conflicts of interest in funding or affiliation?

And of course I assume we want to stay on topic and look at research that isolate amplifiers for some tests, not conflate them with moving parts such as speakers.

</comment></comment></comment></comment></comment></comment><comment><USER15> I built this stereo amp kit a few months ago. Uses single ended 300B tubes with class A bias. Very high quality kit and manual, though I expected that from Japan. Fed directly with a CD player.

[https://www.elekit.co.jp/en/product/TU-8600R](https://www.elekit.co.jp/en/product/TU-8600R)

Also built some single driver, folded horn speaker kits. These pair will with the tube amp.

[https://www.madisoundspeakerstore.com/full-range-speaker- kit...](https://www.madisoundspeakerstore.com/full-range-speaker-kits/fostex- bk-12m-folded-horn-kit-pair/)

I pretty much only listen to string quartets with this setup, and it sounds great.

</comment><comment><USER16> Are there good resources for DIY amps for stereo speakers? Are those much harder/more dangerous to build than headphone amps? I have a pair of KEF Q100 bookshelf speakers that are still collecting dust.

<comment><USER17> The DIY Audio Forum is a good place to start. [https://www.diyaudio.com/forums/index.php](https://www.diyaudio.com/forums/index.php)

Some speaker amps will use mains power and transformers, which means working with high voltage which can be dangerous. But there are some designs which use external purchased power supplies which provide a lower voltage.

</comment></comment><comment><USER18> Building headphone amps doesn't make any sense, IMO. You are not even going to outdo a $1 opamp with all this tube stuff. For headphone amp I use a Mackie Onyx mixer that I bought used on ebay for $80. It also includes a bunch of ADCs and, you know, the entire mixer. And it's more similar to the stuff that was used when actually mixing the songs I listen to.

Where tube stuff still _does_ make sense is guitar amplification, where particular flavors of distortion and frequency response nonlinearities are a feature, not a bug.

<comment><USER19> These days modelling (Helix etc) has reached the point where tube amps, cabs and individual FX pedals can be replaced by a single piece of hardware. As a bass player I ditched my SVT and individual pedals in favour of a Helix Stomp; it's the best musical purchase I've ever made.

<comment><USER5> Guitar/bass player here. I own a few tube guitar amps (Fender Blues Jr, Peavey Ultra 410) and also have a vintage 70s Ampeg V4b. For nearly 100% of my daily playing and recording needs I use Helix Native; it's simply easier, more versatile, and sounds better than anything I can do with my real amps.

</comment></comment></comment><comment><USER20> Class T wins. Choose a modulation frequency high enough and you won't need to worry about analog gain controls.</comment>