A-100 analog modular Website
Andreas Krebs The Bit Modifier / Bit Cruncher is one of the digital modules that can be modulated with analog control voltages. The module is based on a 12-bit converter, which fits quite well for the intended “Lo-Fi” effects. Simply put, the module performs some purely mathematical operations after converting the audio signals into digital information and … Read more
The Xpander filter is based on the multimode filter design of the Oberheim Xpander synthesizer. With a total of 16 filter modes, it is not only extremely versatile, but also sounds very good throughout. If you only want a single filter for a small modular system, then give the A-106-6 serious thought. The filter has … Read more
The A-106-5 is a 12dB filter with two separate outputs for lowpass / notch / highpass (crossfade) and for bandpass. The filter is inspired by the Oberheim SEM filter. Incidentally, “SEM” stood for “Synthesizer Expander Module”, the SEM in 1974 was a small box without its own keyboard and originally intended to supplement a “normal” … Read more
The A-106-1 Xtreme Filter is a real fun box! The technical design is inspired by the filters of the Korg MS-20, but goes very far beyond them: Very differentiated controllable clipping (distortion) of the filter resonance, separate inputs for low-pass and high-pass mode (comparable to the A-101-1 Vactrol filter), as well as a separable feedback … Read more
The module is no longer in production. The A-105 (or A-105-1, there is now the polyphonic A-105-4) is also reminiscent of famous models. An analog SSM2044 filter circuit is used here, which was already used in synthesizers such as the Korg Mono / Poly, the Fairlight II, PPG Wave 2.2 / 2.3 and last but … Read more
The module is no longer in production. The A-101-3 phaser has two sub-units, each with 6 phase shifters (stages): The input signal runs through the 6 phase shifters connected in series and at the output, the original and the shifted signal can be mixed as desired using a “Mix” control. The output of the 6th … Read more
The Doepfer Diode Low Pass Filter is a lowpass filter with a slope of 24 dB. In terms of technical structure, it is similar to a so-called “ladder filter” (which works with a “ladder” or cascade of transistors), such as the Moog low-pass filter. Instead of transistors, however, diodes are used, which make the filter … Read more
The Opto FET filter uses optical field effect transistors. That’s a statement you have to let sink in first. Maybe meditate on it too, it certainly won’t do any harm. Until then, very quietly, the question arises as to what on earth an optical field effect transistor could be and why you need something like … Read more
After the Curtis chip CEM3320 was no longer available, Doepfer had to stop production of the A-123 24 dB highpass filter. It’s a pity, because there were simply no other 24 dB high-pass filters on the market! In the meantime, however, a replica is available with the AS3320, so that there is now a 24 … Read more
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
