discharging a tube amp

[richie]

hi,
can anyone tell me the correct/safe proceedure to discharge (caps etc), a tube amplifier before working on it, changing tubes etc.?
many thanks

 

[Crusher]

I wait about 10 minutes and if amp has a built in voltmeter, watch it until it reads zero. Then take a piece of wire that has an alligator clip on both sides and attach 1 side directly to the case or ground. Then take other end and quickly touch capacitor end and see if I get a spark. Then touch other side of capacitor and do same thing. Then I take clip and attach it to what would be the positive side. I leave it attached the entire time I am working on amp. Otherwise I have worked on a few that I thought were discharged and took lead off and it was like it built up a small charge. That is why I leave it attached the entire time I am working on it. You could also use a chicken stick to start off with. I should have mentioned the first thing you do is unplug unit before doing anything else. Some people after unplugging it, will turn unit in on position and key it. This helps bleed off as well. Since you didn't mention amp these are what I would do.

 

[richie]

thank you for the informative reply crusher
the amplifiers in question are a dentron clipperton l and a zetagi bv2001 mk4
many thanks
73

 

[hookedon6]

richie, your stone mason site is neat

 

[W5LZ]

No idea where it is but there was another thread about this here with several suggestions. Probably the most common was to use a 'chicken-stick' on the tube's plate caps. (Naturally, turn the thing off first, and un-plug it!)
The only thing I'd add to those suggestion is to never, never use your tongue to do that shorting! Spit corrodes plate caps really bad...
- 'Doc

 

[Captain Kilowatt]

No idea where it is but there was another thread about this here with several suggestions. Probably the most common was to use a 'chicken-stick' on the tube's plate caps. (Naturally, turn the thing off first, and un-plug it!)
The only thing I'd add to those suggestion is to never, never use your tongue to do that shorting! Spit corrodes plate caps really bad...
- 'Doc

Is that the only thing wrong with using that technique?