[sdiy] Discrete OTA

[Ian Fritz]

Neil --

The version I have in my cab tracks to better than 0.1% from 100 Hz to 30 
kHz.  I usually don't look at lower frequencies, because errors there yield 
slow beats, but I'm pretty sure it would go at least a couple of  octaves 
lower.

The converter transistors are from a CA3083 array, and the rest of the core 
is basically the Terry Michaels (EN 62) design, with an OPA602 for the 
integrator, a 2N4391 for the FET switch and an LM311 comparator.

A more evolved variant is discussed here:
http://www.electro-music.com/forum/topic-28713.html&postorder=asc

Ian


At 03:05 PM 4/7/2014, Neil Johnson wrote:
>Ian,
>
> > http://home.comcast.net/~ijfritz/sy_cir9.htm
>
>Do you have any figures on log conformity of your dial-a-tempco
>circuit?  Or was that not the focus of that particular experiment?
>
>Neil
>--
>http://www.njohnson.co.uk