This is a true-bypass relay bypass kit for your DIY pedals. It has EQD-style hold functionality, optional optocoupler muting, and more.
Kit includes everything you need except the foot switch:
- Voltage regulator
- PCB with pre-soldered SMD components
- Pre-programmed microcontroller
Build docs here: https://mas-effects.com/relay.pdf
Updated firmware: This will be shipped with an updated version of the firmware with an additional feature: By default it will remember the state of your pedal (bypass or engaged), and it uses a "wear leveling" technique to write to each EEPROM location as few times as possible to ensure it keeps working forever.
Holding the foot switch while powering it up will toggle between auto-on (3 LED blinks), auto-off (4 blinks), and memory (5 blinks).
The TLP222G optocoupler is optional, and mutes the signal briefly while switching. However we're no longer carrying it because
1. It's rarely helpful for most people. It's usually better and easier to fix the root cause of a pop than get the duration and timing of this muting behavior working correctly
2. The part has been discontinued. We'll need to redesign the board to work with an alternate part, but it's not worthwhile because of (1) above.
HOWEVER... if you want to source your own optocoupler, click the "Enable optocoupler code" option otherwise your firmware will not utilize it. By default it's disabled because it necessarily introduces a delay into the switching, which most people don't need or want.