Amp Shocks Me

[jammy]

Greetings. Have an OLD Peavey Series 300 Bass head and cab. Lately, it will deliver a pretty good shock if you touch another guitarist who's touching their strings (or mic, etc.). I noticed it has the old 2 prong power cord. Also has Ground/Reverse switch on front. Have read a few posts here...should I simply unplug cord and turn it 180 degrees and plug back in? Or, is there something wrong with power cord? Also, is this a tube amp?

Any life-saving insight appreciated...

Jammy

[ENB]

Dangerous Situation

Jammy.

I buy a lot of old vintage amps and although I would like to keep them "Vintage" I value my heartbeat more than keeping the factory two prong cord on a vint. amp.

You have voltage leaking to the chasis and yes it could under ideal circumstances KILL you or someone else the first time your lips touch a properly phazed and grounded microphone for instance, Ouch!

I usually totaly disable the "polarity switch" and install a 6 or 8 foot heavy three prong chord and shunt the excess voltage to ground.

I am a novice to say the least but some of these guys can probably tell you specifically how to wire your Pevey amp to accomplish this. You may be able to figure it out on your own but I would get some more input.

When I tinker with an old amp the first time or even later on, it is nice to have a fluke AC voltage detector pen handy, it will let you know if that chasis is hot or not.

The link below will show you how to do the conversion for fender amps.

http://www.theguitarfiles.com/guitarfile644.html

Good Luck and Stay ALIVE

[Don Moose]

Unplug the amp and don't plug it back in until you have installed a 3-wire cord and found a properly grounded outlet to plug it into.

(assumes US/North American wiring)

GREEN - from the ground lug in the plug (usually a green screw) to the amp's chassis. Use a 'star' washer, screw and nut (preferably a 'nylock') to give this connection a good bite into the sheet metal.

Remove/skip/ignore the polarity switch

WHITE - from the wider lug (probably a chrome/nickel screw) to NOT the fuse.

BLACK - from the narrower lug to the fuse.

By fuse I mean through the switch and fuse (in either order) to the power transformer. The NOT fuse side would go straight to the PT.

After you get it wired up and plugged in (and turned on) MEASURE the voltage on the chassis and the input.

Hope this helps (and hope I didn't botch the description).

[Enzo]

This isn't hard. The old two wire cord had two wires in it. The three wire cord has the same two plus a green one for ground. Mount the new cord, solder the white and black wires to the same place the old ones went. Solder the green wire to a solder lug and mount that lug to the chassis with a screw and nut. Drill a hole if you have to.

The PV polarity switch probably had a capacitor soldered to it. That cap went to chassis. Clip the wires on that cap and remove it.