[sdiy] [OT] Analog synths with 2 pole filters

[Tom Wiltshire]

Thanks Ian.

A search throws up this paper, which seems to have a lot of the discussion, with references to the earlier stuff, for anyone else who is following this:

http://electronotes.netfirms.com/EN214.pdf

HTH,
T.

On 22 Feb 2013, at 17:30, Ian Fritz <ijfritz at comcast.net> wrote:

> At 09:36 AM 2/22/2013, Tom Wiltshire wrote:
>> I'm all ears if anyone has better ways of compensating or avoiding the phase lag though. Fancy-pants op-amps?!
> 
> Bernie did a study/writeup on this for EN.  IIRC, he included an opamp model with an extra pole.  From the model he figured out how to compensate for the HF phase shift.  The result was non-intuitive ... not as simple as adding caps at the integrator input.
> 
> Ian