Cap (Physical) Size..

For some reason I can't get away from the idea that bigger caps will sound better, particularly for low frequencies. This idea, as far as I can remember, is not founded on anything I have read or been told, it's just there..

Any ideas/reliable information to either prove me prejudiced against small caps or otherwise???

Edit>Reading back through my post thought I should make clear that I'm talking physical size here, not capacitance value.

As a generalization, IMO you are correct, but what happens to the top end?

What do your ears tell you?

The dielectrics with best properties (e.g. low dielectric absorption, voltage coefficient and distortion) are usually these with worst volume efficiency--which equals to a generalised "better caps are bigger" for a given capacity value. I'd not say that this is especially true at low frequencies, as this is more of a question of the use of the cap (low- or high-pass filter).

Samuel

I will second Sam's comment wrt film dielectrics. Modern electrolytic caps while generally improved may have some compromised parameters as a consequence of reducing size and cost. For example I experienced one newer series part whose leakage character added audible noise in a phantom power voltage blocking application. This was particular to one brand/series, and perhaps isolated but I remain wary of severe size shrinks in electrolytic caps.

So yes there is weak correlation that size matters, but IMO design, or how used, trumps marginal performance differences most times. I wouldn't expect a slightly better cap to rescue a weak design, while some promoters of premium parts would have you believe so. Trust but verify with new improved parts.

JR

[quote author="JohnRoberts"]Trust but verify with new improved parts.
[/quote]

I second that. Experimenting don't harm.

Lytics (which one does generally not use if sound quality is an issue to begin with) I believe tend to go against this rule.

Vacuum as a dielectric is very volumetrically inefficient, and it's hard to imagine how it could be improved upon for sonics. Down from that, teflon is lousy for compactness and legendary (although seldom heard) for quality.