[sdiy] lowpass gate etc - the sounds of capacitors

[Peter Cornell]

John Hardy has some data regarding ceramic caps at his website here:

http://www.johnhardyco.com/products.html

Look at the 990c .pdf, it has some interesting stuff, COG/NPO dielectric vs 
X7/X5 dielectrics.

Regards
Peter


----- Original Message ----- 
From: "Bob Weigel" <sounddoctorin at imt.net>
To: "anthony" <aankrom at bluemarble.net>
Cc: <synth-diy at dropmix.xs4all.nl>
Sent: Tuesday, June 28, 2005 2:24 AM
Subject: Re: [sdiy] lowpass gate etc - the sounds of capacitors


> 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.
>>
>>
>>
>