Expression pedal issues...

[pax-eterna]

So I get to the gig yesterday, and after working fine at the studio, the expression pedal had pretty much no level up top about 40, then between 40-60 jumped to full level? It''s a Boss FV-500L pedal. Also there is a fair amount of digital noise when activating the pedal up and down.

Anyone have any idea about what is happening and how to fix it?

Thanks

[DiSc]

I am using a Yamaha FC-7 expression pedal and had the same issues.

I found that the wiring of the plug (pedal) is opposite to the wiring of the socket (Keylab), so that the potentiometer is connected wrongly: "hot" and "wiper" contacts (or lets say signal "input" and "output") are reversed.

I solved it by interconnecting adapters to separate the lines and swap it:

Yamaha phone plug (male) -> phone plug adapter (stereo, female) to dual RCA (cinch) -> cross red and white line -> dual RCA (cinch) to phone plug (stereo, male) -> Keylab socket

Hope this helps.

Regards,
Dirk