Synthesis Technology MOTM-820
The MOTM-820 is a voltage-controlled lag processor in Synthesis Technology's MOTM line of 5U modular modules. It adds slew to whatever you feed it. Its most common use is portamento: run a control voltage through the 820 on its way to a VCO and the pitch glides between notes rather than stepping.
Classic analog-keyboard portamento circuits (Moog called it "glide") tied rise and fall times to a single pot and an RC filter. The MOTM-820 gives independent voltage control of the up and down times, from 500 microseconds up to 5 minutes. A ganged Up/Down mode brings them back together for standard portamento behavior, and a shape control varies the glide slope from linear to log. Bypass can be remote or on the panel, and it drops the effect out with no DC shift. The lag itself is a 6dB/oct lowpass. The output stage is a capacitive cable driver that can push signals through up to 20 feet of cable without voltage drop. The module also has a built-in multiple, so one input can drive three VCOs or other modules.
The documented record on the 820 is thin. No production years or original price have surfaced, and no independent reviews have turned up. It was sold as a kit, and synthCube lists it in its MOTM 5U category. A single 2019 eBay auction shows one changing hands for £135.02.
Similar items on eBay
No exact Synthesis Technology MOTM-820 listings are live right now — these searches show current Synthesis Technology and similar vintage synth gear on eBay:
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.