[sdiy] Moog filter self-FM questions

[Magnus Danielson]

Neil Johnson wrote:
> Hi,
>
> cheater cheater wrote:
>> I have a question about the control current on the transistors in the
>> moog ladder filter.
>
> Tim Stichcombe has a nice write-up of the filter, plus links to other 
> papers on the subject:
>
>    http://www.timstinchcombe.co.uk/synth/papers.html 
Oh... haven't seen that... Indeed. People should read it, even if I 
guess it would be frightening about the math, but for most part it is 
rigorous. It clearly shows that saying that the traditional EMS filter 
is a -18 dB/Oct filter is incorrect, it's just that it has a very flat 
peak causing that effect when no feedback is given, to such degree that 
audio-wise it is closer to a -18 dB/Oct filter... but adding just some 
feedback should sharpen the response up. Not shown thought. Place for 
improvement.

Regardless, good work Tim!

Cheers,
Magnus