one large cap, or a few added up?

Everything else being equal, I would think it would be better to use several smaller caps in parallel. The smaller caps would likely have lower stray inductance, and lower esr (equivalent series resistance), both of which would then be further reduced by the parallel connections with the other capacitors (parallel connection reduces inductance and resistance, while it increases capacitance).

The only difference in phase effects that I can envision would correspond to the difference in stray inductance, which, although probably minimal, would be in the direction of favoring the parallel combination.

Regards,
-- Al

I would do as Al suggests; a method which use to be in vogue was to take one large cap and bypass it with a small one, this supposidly gave much of the sound of the small ones in a simpler configration but it has been a long time since I built anything so this may be out of date.

thanks guys. It seems that it is hard to find a 120uf cap so I will have to use a combination. Is it better to use 5 24uf, or to stagger the values like 50,33,25 and 12 which total 120uf as well?

John

Hi John,

It's hard to say without having detailed information on esr, stray inductance, etc., and it may not make a significant difference either way, but my instinct would be go with whichever approach (within the same make/model series) minimizes the use of capacitors which are physically largest.

In other words, if the 50 and/or 33 are significantly larger than the 24, go with the five 24's. If not, and if the 12 is significantly smaller than the others, then perhaps go with the staggered values. My thinking is that a physically larger capacitor is likely to have significantly greater stray inductance.

Regards,
-- Al

I'd suggest to use several of the same Capacitors from the same batch and match values as closely as you can. Probably the most important will be to choose something fairly musical and yet reassonably priced and long lasting such as Ansar Supersound polypropylene. Ceramic would be terrible. I would be concerned about mix and match in the high signal level path - caps change shape slightly and "ring" with high voltages applied across them - it might be better to have a closely matched set or you may lose clarity.