[sdiy] Re: Kemet Multilayer (was Walt Jung and Richard Marsh's Capacitors article)

[Chris MacDonald]

Hi Harry, (inline)

> Depends on where you use them...
> For the S/H I'd go with the polystyrene... the dielectric
> absorption is just a little better.  Or do you mean for the
> DAC multiplexer ??? I'd go polystyrene there for sure...

Yes I was thinking DAC multiplexer.  The refresh rate for each S/H is
quite high, every 200uS or so, so I was imagining that leakage wouldn't
factor in (or have I got that wrong).

> Are the Kemet a temperature stable variety ???  

The ones I had my eye on are NPO.  5% tolerance.

> They ARE
> rugged.  We use them for decoupling... and even to simulate the
> gates of very large IGBTs... they are really tough and take a hell
> of a lot of AC dissipation.  But for audio I'm not sure.
> 
> For something like a noise source... why not ???
> 
> BTW are the MiniModulars no longer available as kits ???  

Sorry to say but that is true.  I have sold through the kits that I
originally made up and I just don't have enough extra time to put them
together any longer.  To be honest, demand for the kit has tapered off
quite a bit anyway.

> That would
> be too bad... I've enjoyed mine a lot. I do everything but tune it !!!

:)  Thanks.


> H^)  harry
> 
> Chris MacDonald wrote:
> 
> > Anyone else tried the Kemet "Golden Max" Multilayer ceramics?  I now use
> > a few in the MM to replace some (relatively) big and expensive micas.  I
> > was considering the NPO variety for the S/H in the MIDI/CV as well.
> > They are a bit more expensive than polystyrene (at .01uF), but they are
> > MUCH smaller than any other .01 I can find (which is advantageous in
> > this instance).  Am I nuts?  :)
> >
> > -Chris
> >
> > harry wrote:
> > >
> > > Besides the distortion of the ceramic cap (which MAY not be so bad considering
> > > that it is voltage dependant... and many apps are very low signal voltage)
> > > there is
> > > the often terrible value change with temperature...
> > >
> > > OTOH if it is a guitar fuzzbox who cares ???
> > >
> > > H^) harry