[[L]es]

i upgraded my opamps to burson, but think the output caps can do better than plain standard nichicon bp. how high a rating can i go on the vdc ?

 

[Iniamyen]

Are they direct coupling caps? Assuming everything is line-level, the max voltage you'd see is <2V. So a 5V rating would be sufficient. Having a higher rating wouldn't do anything for you except cost more. You usually want the *lowest* rating that you can safely get away with for that reason.
 
You could probably check the voltage rating on the existing caps to make sure.

 

[germanium]

Quote:

Are they direct coupling caps? Assuming everything is line-level, the max voltage you'd see is <2V. So a 5V rating would be sufficient. Having a higher rating wouldn't do anything for you except cost more. You usually want the *lowest* rating that you can safely get away with for that reason.
 
You could probably check the voltage rating on the existing caps to make sure.

Higher voltage ratings while not providing any extra security if anything goes wrong due to the voltages involved can sound better due to increased plate area providing better coupling in some cases. This works best though with film type caps (mettalised film & film /foil caps) which tend to be noninductive in winding structure. I had this happen when going from 400 volt caps to 600 volt caps in a vaccume tube amp coupling circuit though in this case the 400 volt caps were definately leaking a small amount of current throwing the bias voltage off slightly which probably didn't help. Even so the 600 volt caps (mil spec I might add not the typical overpriced audiophile junk caps that were in there) sounded quite a lot better than the 400 volt MIT caps. Significantly more lively sound than the lower voltage MIT's. One disadvantage though is that these caps were much larger than the 400 volt caps they replaced, about 4 times as large. These 600 volt caps are actually tested to 1200 volts & are leake free at that voltage, that gives you some idea why they were so large. Also one was mettalised film (400 volt) & the other was film foil type(600 volt) both noninductively wound. Both voltage & type contribute to the huge size.
 
There is no such thing as direct coupling caps. You either have coupling caps or you have direct coupling I.E. no caps in direct line with the input or output of the amp. there can be caps though that are not in the direct path of signal that are used to control RF interferance in a drect coupled amp

 

[Iniamyen]

Quote:

Higher voltage ratings while not providing any extra security if anything goes wrong due to the voltages involved can sound better due to increased plate area providing better coupling in some cases. This works best though with film type caps (mettalised film & film /foil caps) which tend to be noninductive in winding structure. I had this happen when going from 400 volt caps to 600 volt caps in a vaccume tube amp coupling circuit though in this case the 400 volt caps were definately leaking a small amount of current throwing the bias voltage off slightly which probably didn't help. Even so the 600 volt caps (mil spec I might add not the typical overpriced audiophile junk caps that were in there) sounded quite a lot better than the 400 volt MIT caps. Significantly more lively sound than the lower voltage MIT's. One disadvantage though is that these caps were much larger than the 400 volt caps they replaced, about 4 times as large. These 600 volt caps are actually tested to 1200 volts & are leake free at that voltage, that gives you some idea why they were so large. Also one was mettalised film (400 volt) & the other was film foil type(600 volt) both noninductively wound. Both voltage & type contribute to the huge size.
 
There is no such thing as direct coupling caps. You either have coupling caps or you have direct coupling I.E. no caps in direct line with the input or output of the amp. there can be caps though that are not in the direct path of signal that are used to control RF interferance in a drect coupled amp

I thought it was clear that by "direct coupling caps" being the subject of the sentence, I meant capacitors that go directly in the signal path. Like I said in that case the OP really doesn't need any voltage rating beyond the voltage of the signal, but I'd go ahead and put a safety factor of 2 or 3 on it just to be sure (maybe 10V caps.)
 
As for differences in the sound... Assuming the same capacitance I don't think you'd measure any differences unless you're really bumping up against the voltage rating (hence the safety factor.) My recommendation would be to go with what you can measure and not spend more on something that won't make any difference.

 

[germanium]

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As for differences in the sound... Assuming the same capacitance I don't think you'd measure any differences unless you're really bumping up against the voltage rating (hence the safety factor.) My recommendation would be to go with what you can measure and not spend more on something that won't make any difference.

Actually in my case the cheaper non audiophile caps were actually the way better cap. Having an "audiophile" part does not garentee good sound.