I’m trying to make my bandmate’s 5153 100W head midi switchable. I’ve found the schematic (here) and knocked up an adaptor box to convert the TRS relays of the switcher to the 7 pin DIN of the footswitch cable. This works perfectly for manually triggering the relays, but as soon as we try switching them via midi the amp refuses to change channels. I know the amp requires momentary relays to switch and the midi switcher in question (Nux PMS2) has the option for short on or long on momentary switching, neither of which work. I know the switcher is functional.
I notice on the schematic for the footswitch (bottom corner of page one of the amp schematic) that there are capacitors on each switch, would wiring these in make the difference? I'm completely at a loss as to why it isn't working, which is frustrating me. Plus I'm trying to save him from having to buy a mini amp gizmo as they're bloody expensive over here.
Hmm. Yeah, if there are caps in the diagram, you'll want to put them in.