[sdiy] Fet to short pedal input?

[brianw]

If you ground the Frostwave to the ARP Odyssey, then there is an increased risk of a ground loop and audio hum. MIDI typically avoids this by using an optoisolator so that the voltage references for each device can remain independent.

Brian


On Nov 28, 2025, at 11:09 AM, el macaco wrote:
> Thanks everyone,
> 
> The portmento pedal is normally closed, push to open the terminals, and yes in my previous message I mentioned it is a mk I odyssey.
> 
> The pedal’s ground is not connected to the jack, sould I ground the velocity output jack to the ody? I assume so.
> 
> An optoisolator is also an option.
> 
> Good to know a bjt can do it theoretically.
> 
> Ed