A-100 analog modular Website
The module is no longer in production. Of all the modules that are no longer in production for one reason or another (most often it was the unavailability of certain Curtis chips, like the CEM3320 here), the A-123 filter was probably the most difficult to replace. There were simply no other 24dB high-pass filters, neither … Read more
The concept of the triple resonance filter A-127 reminds me personally of the resonators in the Korg PS3100, which make this polyphonic analogue dinosaur sound so special. Technically, however, the three integrated filters in the A-127 are more comparable to the SEM filter (even if they are preconfigured differently). In terms of sound, just one … Read more
A fixed filter bank is a “distant relative” of the graphic equalizer. We find 15 frequency bands whose volume is individually adjustable. Behind this are 15 parallel bandpass filters (with 1/2 octave bandwidth), whose output signals can be faded in. In contrast to a graphic equalizer, the fixed filter bank does not have a linear … Read more
The 18dB filter was created on the model of a well-known and popular small bass synthesizer: In principle, a transistor cascade is used here as in the 24 dB Moog filter, but only with three poles instead of four, and thus with a slightly lower edge steepness. The design may have come from a cost-related … Read more
A Lowpass Gate (LPG) is an odd device. It uses a vactrol circuit and couples a low pass filter to an amplifier (VCA). Then why not just use a filter and an amplifier separately? The LPG can be switched between VCF, VCA and the combination VCF / VCA! In addition, the module is built with … Read more
The A-105-4 is a polyphonic filter module based on the SSM2024 integrated circuit (or its replica SSI2144). In principle, we have four A-105 filters with a common control in front of us: Cutoff frequency, resonance (called “Q” here) and input level can be set in the same way for all four filters or also controlled … Read more
