[sdiy] Good choice of capacitor type for Moog 904A VCLPF 4 stages...

[Jean-Pierre Desrochers]

Thanks Dave,
Do you have any cap type suggestions ?
It seams that film caps would be a good choice
But again there are LOTS of film types around..
Capacitor value vs temp  drifting is not a big issue
But microphonics are not welcomed at all.
JP

-----Message d'origine-----
De : Dave Manley [mailto:dlmanley at sonic.net] 
Envoyé : 7 mai 2014 21:05
À : Jean-Pierre Desrochers; synth-diy at dropmix.xs4all.nl
Objet : Re: [sdiy] Good choice of capacitor type for Moog 904A VCLPF 4 stages...

Put pads for different size caps, that way your PCB is compatible with a range of parts, and you can see what you like best.

Dave

P.S. usually polystyrene is reserved for low leakage uses like in a sample/hold.

On May 7, 2014 5:52:30 PM PDT, Jean-Pierre Desrochers <jpdesroc at oricom.ca> wrote:
>I posted that question some days ago with no replies left..
>Here it is again:
>I'm not an engineer and try to figure out what type of capacitor would 
>be the best to be used for the 4 low pass stages of a Moog 904A low 
>pass filter ?
>I read that some type tends to be 'microphonic' and other have easily 
>DC leakage... And I know that polystyrene are greatly appreciated for 
>their 'stable' caracteristics.. (but $$$).
>I found Panasonic has the ECQ series that could be a choice but.. and 
>what about film polypropylene ?
>I'm in the process of PCB design and need to choose the good cap 
>footprints for the 3 capacitors I'll use which are: 1.2uf  0.33uf  and 
>0.075uf like in the original Moog drawing.
>
>Your good advises are WELCOME !!!
>JP
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