Seems logical to ME!!

[Quackzed]

But has anyone actually built somekind of Device that would disconnect the power if anything goes wrong?

a guy invented a saw that stops itself if there is any conductivity between the blade and you...
http://www.youtube.com/watch?v=6X-tj3lk0E8
1:52 shows the interior mechanism at work...
4:22 shows him testing it himself with his FINGER! ouch!

[phector2004]

But has anyone actually built somekind of Device that would disconnect the power if anything goes wrong?

a guy invented a saw that stops itself if there is any conductivity between the blade and you...
http://www.youtube.com/watch?v=6X-tj3lk0E8
1:52 shows the interior mechanism at work...
4:22 shows him testing it himself with his FINGER! ouch!

do you mean something like this?

Code Select Expand

$ 1 5.0E-6 10.20027730826997 63 5.0 50
R 128 144 128 64 0 0 40.0 240.0 0.0 0.0 0.5
f 192 240 128 240 0 1.5
g 128 368 128 400 0
r 128 256 128 368 0 100000.0
w 128 224 128 144 0
r 192 240 192 352 0 100000.0
g 304 112 336 112 0
r 304 240 304 160 0 10.0
s 304 160 304 112 0 1 true
w 192 240 304 240 0
r 128 144 192 144 0 100000.0
w 192 144 192 112 0
r 192 112 304 112 0 10000.0
w 192 144 192 240 0
g 192 352 192 400 0
c 304 240 304 288 0 1.0E-11 19.999999999999332
g 304 288 304 304 0
x 311 148 544 154 0 24 <== this is your finger


(Falstad circuit sim )

EDIT: nope... wouldnt do anything, i realize... neat thing to look into though!

[PRR]

> If you get shocked, then you will remove your leg.

Don't bet your life on it.

Hundred-volt shock often scrambles your muscle-control nerves. "Can't let go". Depending on unknown factors, the paralysis may be just one hand or whole-body. 

And you don't think clearly during an unexpected shock. You are likely to press harder on your foot switch, trying to throw your body back away from the snake biting you.

You work with electricity much like you work with molten metal or deadly snakes, EXCEPT you can't see it.

Most of us manage a little molten solder without massive burns. Don't put your finger there!

Many of us manage poisonous spiders without big swellings. Don't put your hand in dark corners of the woodshed.

--------
Oh: a meter which says "zero" can not be trusted, for the reasons you say.

If the circuit was powered-up today, most 300V amplifiers will show 1V-10V residual AND zero when meter leads are shorted.

If it may be full-drained OR fully-alive, meter a 9V battery just to be sure the meter works.

[jasperoosthoek]

Hmm, solder can burn. As a 12 year old I removed the tip from my soldering iron and completely filled the cavity with solder. It looked just like mercury! As I put it back in the holder I poored all the molten metal on my thumb nail. It solidified instantly transfering the heat to my nail. For three months I had a white spot where new nail material grew under my old nail. I was lucky that it healed completely.

[petemoore]

  Yellow drain wire is just the right length to wrap around the B+ switch and clip to the chassis.
 Drain resistor's wrapped in E Tape so it makes smoke soon, even though the little yellow wire reminder works. Leave the drain resistor connected when you're in there.
 An LED indicator placed on the IEC's I/C lugs warns when AC is in the amp.
 It also tells me useful information there about when AC is not present in the amp, allowing me to correct the custodian that is about to make a quick exit instead of throwing the relevant switch...AC?...cool, now the LED tells me I can switch the amp on without expecting a surge.
 Can't figure out why I'd want the indicator after the switch anyway, tubes lighting is pretty dern indicatey.
 

[defaced]

Why can't we help newer builders (including me regarding this type of build...so I am biased) on this matter insead of just warning them all the time. Seems logical to me... Roll Eyes

Simple.  Effort in = results out.  I usually don't post anything helpful on a stompbox forum unless its about tubes because that's where my experience is.  What I have found is that most of the people I have helped on these types of forums with this kind of top have been unwilling to a) do their own research, b) put any meaningful amount of thought into it, or c) say little more than "I want X, can someone give me a layout/schematic/instruction".  I'm more than willing to help, but it's a two way street and "giving" anything to anyone doesn't teach them how to think/do it for themselves.  I'll still post in tube threads, and I'll still hold the carrot out until I see the person is putting in effort.  But there's no way I'm handing anyone a turn key solution for something that can kill you.  It's not being mean, or rude, or elitist, it's being smart and safe and conscious of the ramifications of one little internet post.

So, what tube related topic are you interested in?  Sounds like you want to build something in the part of your post I quoted. 

[DougH]

I'd like to learn how to skydive. I'll just google for a pdf on it and rent a plane this afternoon. After I finish the pdf on how to fly a plane...