Fun working on amps

[Reeltarded]

lol

I am afraid of heights, and electricity.

Thanks to you guys, I haven't been hurt, and I always guessed right when fixing crap. Thanks for the guess training.

Now, about the flipping switch terror thing..



I hate this part.

[jelle]

Go slow and use a variac.....

[David Root]

Sound advice! I use one. If you do, get an isolating transformer and put it between the Variac and the mains. Weber has a good one, handles 300mA. Some people assume a Variac somehow isolates you from the AC but it doesn't. Be safe!

[ampgeek]

I hear ya!

Even with dozens of builds and multiples of that in repairs under my belt, I STILL use a stick on the first power up. Even with a light limiter in line.

And...I still don't touch anything with my skin until I have done some voltage probing.

Yes...be safe!

Dave O.

[Reeltarded]

A stick? A chopstick, a yard stick, or a 10' pole?

I turn off the mains, plug everything in, put on the rubber suit, the asbestos suit, the foil suit, and the kevlar oversuit, THEN I flip the house mains with a broom stick.

Then I take all that stuff off and change underpants. You shouldn't hold your breath for so long, but I do.

It comes with a bit of experience. I saw Jesus in a mains box once, but the scary thing is he saw me and freaked out. That was nutty. He was like, "WTF are you doing here!!?!". I was like, "Jeees.."..

[jelle]

I hear ya!

Even with dozens of builds and multiples of that in repairs under my belt, I STILL use a stick on the first power up. Even with a light limiter in line.

And...I still don't touch anything with my skin until I have done some voltage probing.

Yes...be safe!

Dave O.

+1. Variac with isolation transformer and even then I measure.

Also...if you touch the amp for the first time....use the back of your hand for the first touch. In case of B+ on the chassis, your hand will contract, in case of the back of the hand it will contract and move away from the chassis and thus away from danger.

If you use the palm of your hand and the hand contracts, it will grab the chassis...not good.

Always have one hand in your pocket, you do not want to lead the current across your heart from one hand to the other...also not good. Just get a set of probes that will allow you to clamp one probe to the chassis (ground) and the other probe to point at the parts you want to measure.

Jelle

[Cygnus X1]

I use a meter to check for voltage on the chassis.

Meters are cheap and give a good idea of what is healthy or not.
Measure current draw on the mains as you bring it up.
Another on filament voltage, and one on B+ to make d*mn sure you don't have a backwards or excessively leaking filter cap.

I've only blown up one amp (literally, an Ampeg V4)...and was lucky I was 20 feet away when I did that.
I've learned from that lesson many eons ago and don't ever plan on doing that again!