[sdiy] ROSSUM'S LADDER FILTER with PNP Transistors

[thx1138 at earthlink.net]

Hi Mattias,

AD810 and AD820, 2n4250 transistors and IMF3958 Fet’s are used in the design of this Filter submodule.

I have the schematic in front of me, dated 9 March 1979.

As to a working module, I would have to see about dragging out my Modular system and see if it will power up after being in storage for so many years.

I could probably do so AP plots if I can get it out to measure.

regards,

Terry 


> On Sep 25, 2016, at 1:14 PM, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> On 25 September 2016 at 20:38, Juan Bermúdez Costa <jubeco at telefonica.net <mailto:jubeco at telefonica.net>> wrote:
> >
> > 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?
> 
> /mr
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20160925/10a1ce0a/attachment.htm>