Zira is in the house ..

[Tony Hardie-Bick]

On 20/11/12 20:22, Paul Maddox wrote:
>   Tony, The filter is not a ladder filter (not possible dur to PCB space
> and power limitations) but it's the next best thing, an NJM2069 which is
> a 4 pole low pass filter used by Korg in the Poly800, DW8000 and so on..

yeah - that's a good filter circuit. i thought i'd mention the ladder
filter design, since it's got something a little extra of its own. I 
think partly
the sound comes from the use of the LM13700, although I can't remember 
what role
that actually plays in the topology (iirc voltage control of the 
resonance, so its
distortion and noise are in the feedback)

sounds like zira is equipped with something entirely suitable :)

Tony (HB)