Saturday, October 25, 2014

Doepfer A-105 SSM 24 dB Low Pass Filter Demo by LesIndes

LesIndes uploaded a long demonstration of the Doepfer A-105 SSM LowPass Filter.

The A-105 is very similar to the A-122 that is made with a CEM chip. But in contrast to the A-122 the A-105 is made with the legendary SSM filter chip SSM2044.
This chip was used e.g. in these synthesizers: Korg Polysix, Korg Mono/Poly, Fairlight II, PPG Wave 2.2 und 2.3, Emu SP-1200, Siel DK600, Siel Opera 6. 
The first Prophets used the SSM2040 - the precedessor of the 2044 - that generates a very similar sound. 

The special feature of the 4 pole low pass SSM2044 is the patented so-called "true open loop design that delivers a characteristic fat sound not available from other devices" (extract from SSM2044 data sheet). 

The module features voltage controlled resonance and a sensitive audio input to obtain distortion - if desired. 
Regarding to the functions, controls and in/outputs the module are identical to the 24dB low pass filter A-122 that is built around a CEM chip, but the sound, the resonance behavior and the distortion behavior are completely different for both modules.

As the special circuit SSM2044 used in this module is no longer available the module has to be discontinued. Sale while stocks last !

Video: DOEPFER A-105 SSM 24 dB Lo Pass Filter Module // Endorphines Furthrrrr Generator

" SSM filter chips were used in many great vintage synths in the synthesizers' hall of fame. such as the original SEQUENTIEL CIRCUITS PROPHET V, EMU E2, PPG WAVE 2 / 3. the filter chip is 2044.

Uploaded by LesIndes
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