Avoiding death while working on amps ?

[suislidE03]

Re: Avoiding death while working on amps ?

I was told that using the standby to discharge is the best way to do it.. on most amps. I think the best way to do this is to start with the amp off.. then just hit the standby switch and let it sit for a couple mins. After that, open it up and check several connections with a multimeter to make sure its drained. It usually will not totally drain, so you will have to drain it manually.

Of course, dont do this and screw up, i hold no responsibility. Maybe i shouldnt really post this.. i dunno.

[75lespaul]

Re: Avoiding death while working on amps ?

I use a long screwdriver with the metal shaft wraped up with electrical tape. This way my hand is not inside the amp while I adjust the trim pot,And if I fumble fingers and drop the screwdriver in the amp. The chances of shorting something out are decressed. I learned the tape trick from adjusting points in my old Hot Rod. ( I geuss Only the 35+ crowd here remember setting points) The old GM's distributer caps had that Lil' window where you could put a Allen key in... If you missed the Allen screw and touched the points... 20,000Volts would surge thru your body. Not my Idea of Fun

I sure remember points! Didn't shock myself with them, but in the mid 80's I bought my 65 or 67 Fender Deluxe and fired it up. Of course, I wanted to see the inside so I took the amp apart. It was unplugged but when I grabbed the chassis--ZAP! Hurt like a *****! I swear, my hair stood up. I'm lucky I didn't get to meet Hendrix, Bohnam & company that day, LOL.

[kmcguitars]

Re: Avoiding death while working on amps ?

I bias live amps all the time, using a bias tool, multimeter, and miniscrewdriver with a plastic handle.

Anyway, a few weeks ago, I couldn't find my plastic-handled miniscrewdriver, and used a solid metal one to turn the plastic bias pot. DOOOOOOHHHHHHH! Dumbest goddam thing I've ever done! As the surge of electricity ran through me, I jumped away from the amp, but it scared the livin crap outta me!! I'm lucky I didn't get connected to it and die!

I use a long screwdriver with the metal shaft wraped up with electrical tape. This way my hand is not inside the amp while I adjust the trim pot,And if I fumble fingers and drop the screwdriver in the amp. The chances of shorting something out are decressed. I learned the tape trick from adjusting points in my old Hot Rod. ( I geuss Only the 35+ crowd here remember setting points) The old GM's distributer caps had that Lil' window where you could put a Allen key in... If you missed the Allen screw and touched the points... 20,000Volts would surge thru your body. Not my Idea of Fun

[PUCKBOY99]

Re: Avoiding death while working on amps ?

If you do it enough times, it is supposed to be hard on the tubes. Doing it once or twice should not be big deal. I'd still check everything, then ground out those big caps while you're working on it.

Gotcha!

Yeah, I was leaning towards if you were gonna be messing around inside, not after every time you play. I'm not sure HOW hard it is on the tubes, but I'll take the words of those that know better.

[Scott_F]

Re: Avoiding death while working on amps ?

Hey Scott, I heard that instead of putting the amp in stand by & then powering down, that if you turn off the power switch & keep playing till you hear nothing coming from the amp, that that discharges whatever power is left in there........any truth to that?

That said, I know nothing about the electronics of an amp & therefore, wouldn't dream of noodling around on the inside without a little education.....go to a tech!!!

If you do it enough times, it is supposed to be hard on the tubes. Doing it once or twice should not be big deal. I'd still check everything, then ground out those big caps while you're working on it.

[Gearjoneser]

Re: Avoiding death while working on amps ?

I bias live amps all the time, using a bias tool, multimeter, and miniscrewdriver with a plastic handle.

Anyway, a few weeks ago, I couldn't find my plastic-handled miniscrewdriver, and used a solid metal one to turn the plastic bias pot. DOOOOOOHHHHHHH! Dumbest goddam thing I've ever done! As the surge of electricity ran through me, I jumped away from the amp, but it scared the livin crap outta me!! I'm lucky I didn't get connected to it and die!

Re: Avoiding death while working on amps ?

Outsource

[newking70]

Re: Avoiding death while working on amps ?

just kidding

[newking70]

Re: Avoiding death while working on amps ?

make sure you stand in a tub full of water bare footed, while you amp is pluged in.......

[DesertRose]

Re: Avoiding death while working on amps ?

ensure its earthed, have spare fuses, tubes are secured ..

[innerdreamrecords.co]

Re: Avoiding death while working on amps ?

Always keep one hand in your pocket. I´m dead serious, no pun intended.

Where were you when I needed you!

I remember I was changing a wall plug in a high rise office building from one side of the wall to the other while it was live. It was taped up really good so I thought it was pretty safe...I grabbed it with both hands and I could feel the current running up my arms to my chest. It knocked me to the floor and almost made me pass out, I think I came very close to visiting the morgue.

[PUCKBOY99]

Re: Avoiding death while working on amps ?

Hey Scott, I heard that instead of putting the amp in stand by & then powering down, that if you turn off the power switch & keep playing till you hear nothing coming from the amp, that that discharges whatever power is left in there........any truth to that?

That said, I know nothing about the electronics of an amp & therefore, wouldn't dream of noodling around on the inside without a little education.....go to a tech!!!

[lastwinj]

Re: Avoiding death while working on amps ?

There are a lot of tube amp safety sites out there. Do a google search.

What not to touch is important, but knowing how to drain the charges is way more important. It's not hard to learn at all. Have a good volt meter to check your work after you're done. Then attach a lead from V1 to ground to prevent any charges from coming back on you. That can happen even though you're not plugged in.

Start at Randal Aiken's site. I'm sure there's some stuff there. Also on the 5E3 forum, there's a LOT of good stuff there.

drain charges? why someone do that. thats the sneaky surprise everyone likes!! to tell the truth i rarely drain an amp. but i also use a multimeter to check for voltages, so either or is doable.

note:watch out for mesa 22 caliber plus. they do not drain. i found this out the hard way.

germ

[Scott_F]

Re: Avoiding death while working on amps ?

There are a lot of tube amp safety sites out there. Do a google search.

What not to touch is important, but knowing how to drain the charges is way more important. It's not hard to learn at all. Have a good volt meter to check your work after you're done. Then attach a lead from V1 to ground to prevent any charges from coming back on you. That can happen even though you're not plugged in.

Start at Randal Aiken's site. I'm sure there's some stuff there. Also on the 5E3 forum, there's a LOT of good stuff there.

[accipiter]

Re: Avoiding death while working on amps ?

https://forum.seymourduncan.com/show...lter+capacitor