Caps in parallel ?

[rreiser]

Has anyone tested the sound difference between two caps in parallel versus one cap to get the same value. For example , a 120uf plus a 100uf in parallel versus a single 220uf. Thanks

[brad347]

I haven't. But I do know that lots of hi fi guys will bypass a larger value cap with a really small value (.001µf or so) because they think it helps something or other.

[jay42]

There's also the approach of paralleling a pass caps of two types. Specifically, polyester film and ceramic.

[Jade]

With the values you stated, I'm assuming you're talking about Cathode Bypass caps, or possibly PS filtercaps.

In either case, You're not going to hear a difference, especially since the value of both caps is rather large, and both would be of the same type (electrolytic in this case)

That being said, where you will find tonal differences to play with would be in coupling stages.

I believe Ken Fischer was a proponent of using Ceramic, and Poly caps in parallel to get the sound of both types of caps in some places.

I've experimented with this a bit, and found subtle differences. The best thing to do, is simply experiment, and let your ears tell you what is right for you.

Jade

[Jade]

There's also the approach of paralleling a pass caps of two types. Specifically, polyester film and ceramic.


Jay said it much more efficiently, while I was busy typing LOL

Jade

[andrekp]

Sometimes if you are using really large electrolytics in your cathode (i.e. 1000uf+) you can improve the treble response in the amp by bypassing that big cap with a regular non-electrolytic in the range of maybe 1uf-.68uf (to taste).

This is because the big electrolytics don't respond properly to really high frequencies, so they tend to dampen them. Putting in the smaller cap can put some back. It's only if you have this problem, then it's a matter of taste.

I've tried it on a few amps, but I always pulled them back out - but then I use EL84 amps with V30s, so they are plenty bright as is!

[Jade]

Sometimes if you are using really large electrolytics in your cathode (i.e. 1000uf+) you can improve the treble response in the amp by bypassing that big cap with a regular non-electrolytic in the range of maybe 1uf-.68uf (to taste).

This is because the big electrolytics don't respond properly to really high frequencies, so they tend to dampen them. Putting in the smaller cap can put some back. It's only if you have this problem, then it's a matter of taste.

I've tried it on a few amps, but I always pulled them back out - but then I use EL84 amps with V30s, so they are plenty bright as is!

Good point.

This same phenomena can also be used in the Power Supply. I've seen amps that responded favorably in regards to hum by simply bypassing one of the big filter caps (40-50uf for example) with a small .047u cap.


Jade

[donnyjaguar]

Most lower value caps have better ESR values so using 10x 10uF instead of 1x 100uF can have its merits. This is most noticeable in high-speed switchers in my experience. Whether there's benefit in audio circuits is a point of conjecture.

[rreiser]

I had a 120uf per pair of EL-84s on the bias circuit and increased it with a 50uf in parallel and really like the change. Thanks for the good info.