[sdiy] lowpass gate etc - the sounds of capacitors

[Bob Weigel]

There are many speculations about various ....seemingly insignificant 
factors in electronic construction.  Ranging from gold plated contacts 
and oxygen free speaker wire (which does at least last longer and 
conduct somewhat more efficiently) to things like this.  I'd also be 
interested in hearing what sorts of tests people have done and base 
their knowledge on.  
   Obviously ceramic capacitors are often used in rf circuits and so 
on..and perform just fine.  Any time you are talking about applying AC 
to a dielectric material there is always a possibility the material will 
posess some kind of response time and or hysteresis effect.  But...if 
something performs fine at 100Mhz you would not expect such things to be 
factors at audio frequencies unless they are noisy or something.  Now in 
an unshielded situation or where microphonics might be a factor ceramics 
are not as good as some other types.  But I'd be interested to hear 
anything documented on it to shed new light. -Bob

anthony wrote:

> I'm in the middle of making a dual lowpass gate like the Buchla 292C. 
> I remember reading someone saying they'd made some each with different 
> types of capacitors for different sounding filters. Before I finish 
> them up and can listen for myself I was wondering just what different 
> capacitors can be expected to sound like in different audio circuits. 
> I think the impact of each different type might be different for the 
> different uses for capacitors in audio circuits - like feedback 
> networks or coupling caps or caps in a filter. In my circuits I'm 
> using all polystyrene in one and a combo of polystyrene and 
> silver/mica in the other. I had thought about using NP0's because I 
> had this funny idea that they probably sound better than most any 
> other ceramic. But then I decided that this was probably silliness and 
> decided to not use any ceramics at all. Do ceramics really sound all 
> that bad? I've never actually taking the time to compare the sounds of 
> variosu capacitors. What would be the best kinds of circuits to use to 
> test how capacitors sound? I've been wanting to make a headphone amp 
> out of some medium-mu twin-triodes - maybe that'd be good.
>
>
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