vcf11 update

[mbartkow at ET.PUT.Poznan.PL]

tg wrote:

[...]
> There is also info on the diode/tranny filter and a extra EG/LFO
> that's a little unusual, that didn't make the final design.

Tom, 

I just have looked at your switched diode/tranny structure. I like
the idea of lfo-based type selection for special effects.
On the other hand, I doubt - isn't it more efficient to allow
both structures to operate simultaneously ? I think it needs only
few more components and saves the 4053 multiplexers. 
You would get the possibility to:

1) stack them in series,
2) connect them in paralel and apply a voltage controlled blend
of their outputs,
3) configure them in some kind of ring or in other feedback
oriented processing, possibly with some nonlinearity inserted.

This is probably too late for this project, but I would better
welcome the mux/switches used to reconfigure the whole structure
between LPF and HPF (that one you develeloped recently). Other
possibilities (reported AFAIR by SC or JH) are to allow switching
the output between the top of the ladder and the second pair of
stages (for 24dB/12dB selection). Switching the feedback tap
(with phase inversion being taken care of) was not so exciting,
as it seemed to be at the first sight.

Your circuit is flexible, but I think even more flexibility may
be gained with almost no additional cost.

kind regards,

mb


--

Maciej Bartkowiak
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