Any idea of what might make a SS amp send voltage down the instrument cable plugged into the unput jack? Background:- Usually I set up for a gig starting at the bass, then working through the signal chain back to the amp. (Bass--->Pedals--->Amp--->Speaker cab). Yesterday I decided to do it the other way around for no real reason. I plugged the cab into the amp, plugged the amp into the power point. Plugged the instrument cable into the input jack - so far so good. When I went to plug my instrument cable into the output of the pedals, I got an electric shock. Not a big one thankfully, but enough to make me pull my hand away in a hurry. At first I thought it was the pedal, so I tinkered with it but I wasn't able to reproduce the shock. Then when I again went to plug the instrument cable into the pedal , I got a second electric shock. At that point I realised the shock only happens if I'm holding the instrument cable in one hand, then touch something metal. The shock persisted even after disconnecting the speaker cab. I was also able to reproduce the shock using 4 different instrument cables. I plan to take my amp to a tech and use my spare in the meantime. Any ideas what the tech is going to tell me?