Twin grounding issue, getting shocked...

[Tony6Strings]

I've been having this issue with my Twin. It keeps shocking me when I go to turn it on and off. As soon as I touch the "on" or "standby" switch I get shocked, regardless of if it's already turned on or not. Just has to be plugged in. What's funny is that it's never happened at my home, not even once. But without fail, every other place I've taken it to play, it has shocked me. At this point it's a minor annoyance, I just put my sweatshirt over my hand to turn it on or off. But I want to get it figured out. Any ideas?

[hippieguy1954]

Yea, that can be very annoying. Odd that it happens everywhere except home.
Does it have a 2 prong (original) or 3 prong plug on the power cord?
Has the ground switch been bypassed? It should be if the cord has been replaced with a 3 prong plug. Let us know.

[Tony6Strings]

It's got a three prong plug. I have not as of yet opened it up to have a look at anything... For what it's worth, I don't get shocked when I touch the strings of my guitar. Just trying to be grateful for the little things, as I've heard of people arcing off the mic at dangerous levels when playing through a improperly grounded amp... I can see it now... "Lazy Lightning, sleepy fire in your eyes..." ZAP!!!

.................... Only funny till it happens...

[gr8fullfred]

There is obviously something wrong going on here as this does not usually happen. Has your twin been modified with a 3 prong grounded cord? If not it needs to have this mod done. I would take it to a good tube amp technician to be fixed and might as well have the tech go over the amp while it is there. If this happens at only one venue, it could be a problem with the venues electrical situation (not all that uncommon). Another way to eliminate this situation is to make sure that all of your equipment is plugged into the same outlet. And if you ever touch the mike and get zapped
then again often if everything is plugged into the same outlet this can fix the situation.

You can buy an outlet tester at Home Depot or other such place, for around $10. It is a pretty good idea to have one of these, so if you have a problem at a venue, you can plug this little thing in and see whats up. You can explain it to the venue owner, and maybe he will get it fixed.

My friend, who I jam with, has one outlet in the jam room that is wired wrong. We do not use this outlet. If we do, we get zapped by the mike, since the PA is plugged into a correctly wired outlet.

[waldo041]

do you have powered pedals? does it shock you with the guitar and pedals plugged in? does it have a ground switch? when was the last time the amp was recapped?

peace,
waldo

[hippieguy1954]

Sure it's not static? Just thinkin...it's very strange that it never happens at home.

[gr8fullfred]

It does not happen at home because the home outlets are wired correctly. The Venue outlets may not be.
And static discharge only lasts micro-seconds, not enough to prompt a post on the board.

Chances are its a strong shock which I have encountered a couple of times and it is very unpleasant. Find the interview where Bobby talks about "our sound man at the time decided to reverse the ground" referring to the deads performance at Woodstock. OUCH!

[hippieguy1954]

Yes, you are right, but I have gotten some intense static shocks. I'm sure your right about the venue receptacles. As long as the amp is wired correctly with a 3 prong as well as Waldos' suggestions, there isn't much else he can do as far as the amp is concerned, I'm pretty sure.

[Tony6Strings]

It's definitely not static. It's a strong enough shock to make you jump back and curse, and it's not something that's only happened once or twice. Yes, it has been modded with a three prong grounded plug. As of yet I don't know if the three way ground switch has been disconnected, all I know is that it doesn't do anything to keep me from getting shocked. No powered pedals, no shock at all through the guitar or when picking up cable ends that are plugged into the amp... If it is the venue's electric that is at fault, more than one place has it wrong, including the auditorium at my college. It's just so damn weird that it would NEVER happen at my house. I don't understand it. Regarding a recap, it's on the to do list, as well as a tube socket that is doing some funny things...