This is a voltage processor module based on designs by ARP and MFOS.
There are two sum sections: One has four inputs, two with attenuators (normaled to -10 V and +10 V) and two with fixed unity gain; the other has two inputs, one with attenuator (normaled to +10 V) and one with fixed unity gain. Each sum has two outputs, normal and inverted.
There also is a lag processor section. Switches allow selection of slow or fast ranges and RC or linear ramping, and a knob adjusts the lag time.
The sum sections are derived from the ARP 2600 schematics. Differences:
- Obviously, this is a module, so there is no normal connection to keyboard CV; instead the second input of the first sum is normaled to +10 V.
- Added second inverting stages for normal plus inverted outputs.
- TL07x op amps in place of LM301.
- Added series output resistors.
The lag processor is based on a section of the MFOS Multi Function Module. Differences:
- Common input and output for both linear and RC circuits.
- Shorter minimum linear lag time.
- 1k series resistors on outputs.
Github repo:
Some boards and panels will go up on Tindie soon.
Blog post: Processing voltages – Analog Output