// REVIEW //
This is a halfway decent preamp for $100 but do yourself a favor and IMMEDIATELY replace the tube in it.  It comes with some Chinese piece of junk tube that will make your lead vocal sound like my cat hissing and farting into a tin can.  Try a Sovtek 12ax7 or a JJ -- I like the Sovtek but feel free to ask the opinion of your local tone junkies.

// HOW TO SWAP THE TUBE //
1. Remove all the screws and pop the silver plates off of one or both sides
2. Pull the black metal casing off
3. Gently rock the glass tube back and forth to remove from the white thing it's plugged into.  Be sure to apply a bit of counter pressure...
4. Pop in the new tube
5. Put the casing back together.
6. Write to Presonus and politely suggest that they pony up the $12 for a better tube so that people such as myself don't give their product 3 stars instead of 4.

If you're noticing that the tube is breaking up really easily, well, you get what you pay for!  These things just don't have the voltage you'll find on higher end preamps.  I usually find that putting the Drive knob (which controls the tube) at about 9 o'clock and the Gain knob at 1 o'clock gives me good volume and a touch of tube warmth without distortion or hiss.  I'm using this thing with an AT4040 and I'm pretty happy with the results considering that I've heard the same mic through much more expensive preamps before...
// REVIEW //
This is a halfway decent preamp for $100 but do yourself a favor and IMMEDIATELY replace the tube in it. It comes with some Chinese piece of junk tube that will make your lead vocal sound like my cat hissing and farting into a tin can. Try a Sovtek 12ax7 or a JJ -- I like the Sovtek but feel free to ask the opinion of your local tone junkies. // HOW TO SWAP THE TUBE //
1. Remove all the screws and pop the silver plates off of one or both sides
2. Pull the black metal casing off
3. Gently rock the glass tube back and forth to remove from the white thing it's plugged into. Be sure to apply a bit of counter pressure... 4. Pop in the new tube
5. Put the casing back together. 6. Write to Presonus and politely suggest that they pony up the $12 for a better tube so that people such as myself don't give their product 3 stars instead of 4. If you're noticing that the tube is breaking up really easily, well, you get what you pay for! These things just don't have the voltage you'll find on higher end preamps. I usually find that putting the Drive knob (which controls the tube) at about 9 o'clock and the Gain knob at 1 o'clock gives me good volume and a touch of tube warmth without distortion or hiss. I'm using this thing with an AT4040 and I'm pretty happy with the results considering that I've heard the same mic through much more expensive preamps before...