I have a couple mods I would like to make to my SWR Bass 350. First, I want to put a jack to plug in a footswitch to mute the speakers for tuning. Second would be an adjustable pad and groundlift switch for the XLR out. Does anyone know who could do this for me and how much it would cost, if it's even possible?
the best way to mute the speakers so that you can tune is to use a simple/cheap A/B switch in your signal path. This way you can send output A to your rig and output B to your tuner. Put the A/B switch first inyour path. Before any effects, and before any DI box to the house PA. It's quiet, cheap, and effective.
As for teh pad and groundlift, there are some simple barrel type connectors from shure that have these options. One is simply a ground lift the other has pads of (i think) -5, -15, -20db.