Both Expression pedal jack 1 and 2 send >3v on both tip and ring

[joeman]

Hi, apologies if this is not a “technical issue” and simply user ignorance.

Goal: modulate matrixbrute via expression pedal input with eurorack modules.

Process: use a “floating ring” cable.

Discovery: the matrixbrute is sending around 3v on both tip and ring (not just ring as manual states). This is the case with both expression pedal inputs.

Have also tested this using a few different trs cables and a trs to tip / ring splitter y cable. In all cases the 3v is present on both tip and ring.

Does anybody have any advice on how to proceed with my initial goal? (Using the floating ring cable doesn’t stop ~3v being sent into whatever I plug this cable into.. not ideal...?)

Thanks for your help!

Edit: I also performed the same tests using the same cables on 2 other synths (yamaha and dave smith brands) and in both the other synths' cases, the ~3v was NOT sent on both tip and ring.

[DrJustice]

Although I have not seen the schematics, I'm pretty sure that's just a weak pull up on the tip in order to keep the pedal signal "open" when no pedal is plugged in.

You can safely apply a CV in the range 0 - 3.3 Volts on the tip with the shield as your ground. The pull up is most likely high impedance and any normal signal you connect will overcome that.

[joeman]

Thank you for your response and info. I appreciate the help!