SQ affect of using 2 caps instead of 1?

[hugz]

Hey all

I've got some 0.47uf clarity caps. I was thinking of using two of them in series to replace the 1uf ratshack input cap on my amplifier. I gather that using two 0.5uf caps in series is electronically the same as using one 1uf cap.... but will there be any negative affect on the sound quality from using two caps instead of one?

 

[beerguy0]

Quote:

Originally Posted by hugz /img/forum/go_quote.gif Hey all I've got some 0.47uf clarity caps. I was thinking of using two of them in series to replace the 1uf ratshack input cap on my amplifier. I gather that using two 0.5uf caps in series is electronically the same as using one 1uf cap.... but will there be any negative affect on the sound quality from using two caps instead of one?

You want them in parallel, not series. Capacitance adds in parallel. (You're increasing the area of the plates). I wouldn't expect any negative effect on sound quality.

 

[LawnGnome]

Quote:

Originally Posted by beerguy0 /img/forum/go_quote.gif You want them in parallel, not series. Capacitance adds in parallel. (You're increasing the area of the plates). I wouldn't expect any negative effect on sound quality.

I think he is talking about putting them as coupling caps.

Where putting them in series is adding the capacitance.

If he is using them as bypass, then you are correct.

 

[tomb]

It makes no difference what the cap is being used for -

If the two caps are in series, then:
Ctot = 1/(1/C1 + 1/C2)
in parallel, then:
Ctot = C1 + C2

Conversely, resistance is just the opposite -

For two resistors in series, then:
Rtot = R1 + R2
in parallel, then:
Rtot = 1/(1/R1 + 1/R2)

This is fundamental Physics/Electricity.

 

[LawnGnome]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif It makes no difference what the cap is being used for - If the two caps are in series, then: Ctot = 1/(1/C1 + 1/C2) in parallel, then: Ctot = C1 + C2 Conversely, resistance is just the opposite - For two resistors in series, then: Rtot = R1 + R2 in parallel, then: Rtot = 1/(1/R1 + 1/R2) This is fundamental Physics/Electricity.

But capacitors can be run in series with the signal, and in series with themselves, or in series with the signal, but parrallel to themselves.

And

between signal and ground, but parrallel to themselves, or between signal and ground, but in series.

 

[Fitz]

Don't let LawnGnome try to confuse you, beerguy0 is correct, you'll want to wire the two caps parallel to each other.

 

[hugz]

oh i'm confused

does everyone concur that using two caps where one would be suitable is OKAY as far as sound quality goes?

 

[MisterX]

Quote:

Originally Posted by hugz /img/forum/go_quote.gif oh i'm confused does everyone concur that using two caps where one would be suitable is OKAY as far as sound quality goes?

Yes..... and in some cases two smaller caps in parallel actually perform better then a single large cap.

 

[TzeYang]

you want the caps to be PARALLEL TOGETHER. But they are both connected in SERIES with the signal.

 

[hugz]

yup i get it, and unless anyone complains anytime soon i'll replace my 1uf input caps with 2x0.47uf clarity caps.

Garbz has advised me that, althought I want to try keep my input caps at around 1uf to prevent bass roll off, it is okay to replace my 1uf OUTPUT caps with a single 0.47uf cap. does everyone agree with this?

Currently there is a 1500uf electrolytic cap with a 1uf ratshack cap in parallel. If I do a swap, it would be 1500uf electrolytic with a 0.47uf clarity cap in parallel

remember that my sole goal is to improve sound quality. i happen to have some 0.47uf clarity caps on hand which is why they are my weapon of choice

 

[tomb]

If the 1500uf electrolytic is truly in parallel with your film cap on the input, there is no danger of losing bass. However, signal through the film cap will sound better. So, the higher in quality you make the film cap and the larger you can make it relative to the electrolytic, the better will be your sound.

My guess is that a single 0.47 Clarity cap will make a huge difference over the 1uf Rat Shack cap, adding another 0.47 Clarity cap - probably not so much difference after that (but probably still worth the effort). IMHO and YMMV, of course.

 

[nikongod]

FWIW, i am not the biggest fan of "bypassing" big electrolytic caps with film because it can cause a weird "smear."

i have recently realised that the "smear" is sometimes "less bad" than the non-linearity of the cap (i mannaged to find an electrolytic with a VERY non linear response in the audio-band) but when i can go without a bypass cap i personally would.

unless this is a high voltage amp i would get better 1500uf output caps and run them un-bypassed. you may get by less expensive STILL than jsut the price of the film cap...

at the end of the day experimentation yeilds the best results, so please do. but DONT be afraid to run the amp without the film cap there.

 

[hugz]

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif FWIW, i am not the biggest fan of "bypassing" big electrolytic caps with film because it can cause a weird "smear." i have recently realised that the "smear" is sometimes "less bad" than the non-linearity of the cap (i mannaged to find an electrolytic with a VERY non linear response in the audio-band) but when i can go without a bypass cap i personally would. unless this is a high voltage amp i would get better 1500uf output caps and run them un-bypassed. you may get by less expensive STILL than jsut the price of the film cap... at the end of the day experimentation yeilds the best results, so please do. but DONT be afraid to run the amp without the film cap there.

this "smear" is what i was initially worried about with running the two input caps in parallel. it seems that the signal is being split in two, run through two possibly not identical devices, and then put back together again.

i remember that i once bypassed either the input or output all together (output i think) and it was terrible

a lot of offset. fortunately i did it on my test speakers

 

[nikongod]

the "smear" is smaller when you use 2 identical caps in parallel. i doubt it will even be audible. some people do like to run 2 identical non-polar caps "head-to tail" in parallel because they say it sounds better that way. i dunno if it sounds better or not, but its worth trying.

if the amp needs an input or output cap it should be there... dont skip that

 

[amphead]

Yeah, don't put DC on your phones. An output cap of high quality!! And I can speak volumes about what bad ouput caps sound like. Been there, done that!