Vitamin-Q capacitors - A sound myth or legend?

[Cliff Matthews]

Lately I got some work shutting down and scrapping some big tri-phase inverters. Each of 3 control boards contained 4 x 0.1 uf - 1000v paper-in-oil capacitors with no-leak glass enclosed ends (1989 non-pcb type). I was surprised to find these are wanted by musicians for tonal quality, but alas, mostly in the 0.22 and 0.47uf sizes.

They all check good and in spec, but are there any legit uses for these? (kind of small uf for input caps and I'd rather use ceramic..)

[Sigmoid]

I don't think the .1uF is a huge problem. You CAN wire capacitors in parallel...

I'm sure people building custom guitar amps and the like will gladly buy these if you listed them on eBay.

[f5r5e5d]

musos often have lots more superstitions than EE knowledge - but instrument amps are meant to be artistically expressive - so some parts choices, circuit topologies that do make amps with audibly different distortion characteristics can be the wanted outcome

[TimFox]

Guitar amplifiers are not intended for high-fidelity, low-distortion operation since the non-linearity is part of the sound production.

[Zero999]

They all check good and in spec, but are there any legit uses for these? (kind of small uf for input caps and I'd rather use ceramic..)

Ceramic though can often be bad for audio and cause distortion. Film capacitors are normally recommended for audio purposes because they're low distortion.

However Vitamin-Q capacitors for audio is probably audiophoolery.

[Gyro]

Without trying to provoke an Audiophoolery war ...

The one difference I can see between oil caps and other types is ... well, the oil. I've used oil caps (the Russian mil ones) in speaker crossovers very successfully - they do sound cleaner there. I think the reason is simple mechanical damping of the plates provided by the oil, maybe that and the fact that they are foil and not metalized. We all know that film caps can sing (ceramic too), I've never heard an oil cap even whisper.

Of course that's in crossovers where there's significant ac current and voltage swing across the caps. In low level coupling (or maybe filtering) applications, that's a different matter, maybe (probably )dielectric properties are the dominant factor, maybe at low levels sensitivity to mechanical vibration damping matches the miniscule stresses generated. Who knows. I'm not going to stick my neck out on that one.

[Cliff Matthews]

Ceramic though can often be bad for audio and cause distortion. Film capacitors are normally recommended for audio purposes because they're low distortion.

However Vitamin-Q capacitors for audio is probably audiophoolery.

Oops sorry, I meant ceramic dipped Mylar and not ceramic disc. I guess from old-times ceramic disc got shortened to just ceramic, but I see lot of caps nowadays are dipped in ceramic. Reminds me of my glazed coffee mug... dang, already time to brew another pot. 

[Sigmoid]

However Vitamin-Q capacitors for audio is probably audiophoolery.

It may be. But the question was, is there a legitimate use for these. Yes there is. I'm not familiar with oil caps and what they do differently, but different capacitor constructions do have different behaviors. Whether (and in which cases) that really contributes to audio quality is up for grabs though.

One thing is for sure. Audio guys will be glad to pay for them, and selling them is nowhere near the level of selling magical sound-bettering pebbles or $10k "quantum dampeners".

[Cliff Matthews]

One thing is for sure. Audio guys will be glad to pay for them...

Ok, I'll bag 'em-up and soon I'll see if the local den of metal-heads can drop me $25 for all twelve.

To think, I thought they were glass ended tantalum's, but when I found they were paper-in-oil - I headed straight for the sink to wash-off PCB's. I ate my sandwich peacefully, after checking wiki for PCB outlaw dates. 

[edavid]

Oops sorry, I meant ceramic dipped Mylar and not ceramic disc. I guess from old-times ceramic disc got shortened to just ceramic, but I see lot of caps nowadays are dipped in ceramic. Reminds me of my glazed coffee mug... dang, already time to brew another pot.

That is epoxy, not ceramic.  Think about it - how could you put a mylar capacitor in a kiln to fire a ceramic coating?