Transposition and Patch Switching Box by The Electronic Peasant

video upload by epeasant

"A very useful modular synthesizer utility for VCO transposition and octave switching, as well as audio and CV signal switching.

The Transposition & Patch Select module features two six-octave switch banks, a one-octave keyboard, and four independent analogue signal switches. External volt/octave CV signals can be summed with the transposition controls, making it easy to change octaves or keys while playing or sequencing without repatching. The built-in keyboard also provides a gate output and can be used on its own as a simple control keyboard.

The four analogue switches can be used to quickly change audio or CV signal routing at the push of a button, making the module particularly handy for live performance and experimentation.

Constructed using discrete logic and analogue ICs with no microprocessor or programming required.

Complete construction details, photographs, circuit description, and the full schematic are available at The Electronic Peasant: www.epeasant.com/transwitch/transwitch.html"

"Changing keys, octaves, and patches at the push of a button!

A handy utility module for volt/octave transposition and audio/CV signal switching. Many modular synthesizer VCOs don't have built-in octave switching capabilities, which are useful for extending the range of a keyboard. Dynamically changing keys and octaves while using a sequencer is often not an easy or ergonomic process. Unplugging and plugging cables to modify a patch while playing can be cumbersome and inconvenient as well. This project provides the capability to easily and automatically do all of those things in one handy box.

The module includes a pair of six-octave latching switch banks, a one-octave switch keyboard, and four SPDT analogue switches. There is a combined output that mixes one of the octave switch banks with the keyboard output so that they can be used together, and the keyboard has a gate output included as well, so that it can be used as a freestanding keyboard. The keyboard circuit itself is adapted from Ken Stone's CGS10 Pedal board/Mini Keyboard project. Both of the octave switches and the keyboard include a CV input for precision summing of external volt/octave signals with each switch output."

See The Electronic Peasant for additional details.