[sdiy] ROSSUM'S LADDER FILTER with PNP Transistors

Mattias Rickardsson mr at analogue.org
Sun Sep 25 22:14:43 CEST 2016

On 25 September 2016 at 20:38, Juan Bermúdez Costa <jubeco at telefonica.net>
> The 1100 used a Moog ladder as ITS core element, but I wanted to isolate
the audio innate characteristics of the ladder filter from colorations
resulting those from the input level-shifters and output amplifier used in
the Moog 904A".
> Regarding the 1100 output stage, Dave says "I then a designed a
completely new output stage for the ladder; esta circuit has never (to my
knowledge) Been used outside my designs The entire signal path was DC
coupled and the resonant feedback. path phase compensated. The 1100 was my
favorite sounding filter (I liked it more than the SSM2040 I later
invented, and kept the 1100 as E-mu's modular lowpass in preference to a
cheaper 2040 design).

Thanks for the very interesting read.
Are there any good sound examples of this filter?

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