fdd5d689_e_Notes_on_Coupling_Capacitors__Impressions_HV
[Brand] V-Cap Oil Impregnated Metallized Polypropylene (OIMP), 4.7uF, 250V $60.00 [Impressions LV] . [Rating] 4½ [Impressions HV] 
There is no way around the fact that these are really expensive caps. I use them for parafeed duty in the output stage of a DAC with Magnequest nickel core output transformers, and these caps cost 60% of what the transformers cost (they cost the same as the steel core version). This bears mention because people often are willing to use caps over transformers for coupling because transformers tend to be really expensive. It is also worth mentioning that while these are less money that something like a Mundorf Silver/Oil 4.7uF cap, they are also only rated at 250V compared to Mundorf's 1200V rating, so in a sense you get less for your money. That said, in another sense you do get something else for your money which is a really special capacitor. These are, simply put, the best cap I have used in this size. Yes, some other caps (perhaps including V-Cap's own teflon capacitor) might be better overall, but in general either they do not come in such large sizes, or they are way too rich for this reviewer's budget (for comparison, V-Cap's 3.3uF 250V Teflon cap is close to $500, and Auricap's 3uF 200V version is $200 with the 600V version at near $1000). Indeed, AudioNote's 4.7uF 300V Copper foil and mylar in oil, the same basic technology, is almost 3x the cost. So, in its price range, I think this is about as good as it gets. So, what are the sonic qualities, you might be asking? It's hard to say, but basically, they are clear and just get out of the way. Really, that's about it. What more could you want?
ecp audio diy: Some Notes on Coupling Capacitors
Impressions HV