[sdiy] Formant 24dB filter

[Magnus Danielson]

From: René Schmitz <uzs159 at uni-bonn.de>
Subject: Re: [sdiy] Formant 24dB filter
Date: Mon, 04 Jun 2001 23:36:09 +0200

> You're probably plagued by the phase reversal of the opamps. 
> I have had this latchup problem in OTA based filters where I've used TL084s
> as opamps. 
> The solution could be to replace those opamps with ones which are free of
> phase reversal. However I didn't replace the opamps, merely decreased the
> input amplitudes, so that it is less likely that the opamp is overdriven,
> and a resultant change in sound. Haven't had it for several years now.

Could be a solution, but I'd first look at the DC offset errors. For
me they seem more of a reasnoble trouble, but I'll look at this one
too.

Cheers,
Magnus