Open letter

[terry michaels]

Message text written by Paul Perry
>And what is more mystifying, is why nobody made a state variable filter
with a 
multiplier as the active voltage control element. I think the technology
was aroundat the time, in analog computers.
<

Hi Paul:

Actually, someone did.  The Electronic Music Labs (EML) model 100 used two
MC1495 multipliers with opamp integrators to create a voltage controlled
state variable filter.  I remember seeing a similar circuit as a design
example in some early '70s IC data books also.

BTW, does anyone know where I can get schematics fo the EML 100 or 101? 
Mine are hand drawn from reverse engineering the synths, and are somewhat
inaccurate.