I have never changed power tubes before and I was wondering if there was a potential to be electrocuted when removing power tubes. I have heard some people say you have to drain compactors, do you have to?

Ken, please take caution

While I am no expert by any means in amp maintenance, the capacitors in an amp may contain potentially lethal voltages and will need to be drained, even if the amp has sit idle for days.

Once the caps are drained, you may begin worrying about biasing the amp and new power tubes.

More knowledgeable folk will chime in. Be sure to keep the amp unplugged and turned off before doing anything. Best yet, it may be a good idea to have the amp looked at by an experienced tech if it's your first time.

One thing to bear in mind when changing any tube is the possibility that the amp's power supply filter capacitors may remain charged. I'd recommend unplugging the amp then leaving the power switch and standby switches in the ON position for at least five minutes - this ensures all the high voltage caps are connected to ground via the bleeder resistors.

There is the potential (was that pun intended?) to get a shock when inserting a tube. Breaking the glass envelope obviously means trouble but not just from inconvenience and broken glass. In the case where the glass breaks as you're plugging a tube into an amp that isn't fully drained, the anode plates will go live and really, you don't want to touch those.

If in doubt, get a tech to do it!

EDIT: Disclaimer, I'm not a qualified tech, seek professional advice if you don't know what you're doing inside an amp. Blah blah blah etc.

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Best to post all amp questions in the Modern or Vintage amp sections (as appropriate) of this forum where there are a number of qualified amp techs, builders, and designers available to answer questions.

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Bill

Yea...I gotta agree all the way around on this one. While I certainly encourage people to learn what all this music gear they use night after night is about, yes...those amps can and do have the potential (just echo'd the joke) to SERIOUSLY knock you on your butt! In my first band, I was playing thru my '73 Bandmaster and the bass player was playing thru an ungrounded Peavey tube head. We didn't have a PA system back in those days so I was running my "Radio Shack High Ball" thru my amp while the bass player was singing. Dude... I kid you not...at least 4 inches of arc OFF THE GUYS LIPS and it literally tossed him over a couch!!!!!!!!!! And this wasn't even dinkin' with the tubes or caps directly!!! He was still breathing and did later go on to reproduce...but seriously, this just ain't the kind of sh_t to f_ck with if you don't have some guidance.

If you haven't already, go talk to the folks in the amp forums here before you touch ANYTHING! I would also STRONGLY recommend picking up a copy of Aspen Pitmann's "The Tube Amp Book" and reading it cover to cover before you touch anything in the back of that amp! Changing tubes isn't really -that- big a deal, but touch the wrong thing and yes...it could KILL YOU.

Just my own opinions,
Jim

I was bitten by the B+ of a Blackface Twin Reverb (a REAL one) in college many years ago. Knocked me backwards off my stool and into the wall 6 feet behind me.

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Bill