Temperature-compensated resonance ( was Re: [sdiy] RE: [AH]

[Cary Roberts]

>This only shows the sad state synth designs are in. Most high quality
>equalizers have tempco Q.

Can you name some EQs that have tempcos?  I'd like to think I have a number
of high quality EQs and not a single one has tempcos in it.  This list
includes Neve, Focusrite, API, Melcor, Electrodyne, Quad Eight, Sphere, ADR,
and Troisi.  In the recording world inductor based EQs are considered
"better".  The best sounding EQs I have are Sphere 910s which are inductor
based.  Very clever circuit design.  I should also say my next favorite EQs
are gyrator based (Focusrite ISA110s and Peter Trois 518s).  The Peter
Troisi units use no transformers nor esoteric parts so they were a pleasant
surprise. 

>The way I think of this is that I can't figure out all ways that
>people will be using my synth/eq/computer program/other invention,
>therefore I shouldn't compromise where *I* think that *I* don't need
>the accuracy. I usually go and ask experts, I'm definitely not the
>best expert in the use of anything I created.

The capcitors in most EQ circuits are +-10% at best.  You'll occasionally
find polystyrene in a few designs but that seems to be the exception.  I
doubt the inductors are better than +-10% either.

-Cary