A-100 analog modular Website
The module is no longer in production. The A-121 is an early but very neat filter design by Doepfer. Unfortunately, the Curtis module CEM 3320 used is no longer available, so the module is no longer commercially available. It’s a shame because it has a very unique sound character and some interesting technical features. From … Read more
I often used my A-111-5 as a “stopgap” when I quickly needed another simple synthesizer voice and maybe was just too lazy to patch extra VCO, VCF, VCA, ADSR and LFOs for such a secondary voice . I was often plagued by the “guilty conscience of the modularist” when I ignored the far-reaching possibilities of … Read more
The module is no longer in production. The A-107 was basically an Xpander filter (A-106-6) with greatly expanded filter modes (36 instead of “only” 16) and a digital control for morphing between different filter modes. The filter itself is of course purely analog. The A-107 works with “filter chains”: Such a chain consists of a … 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
