This Little Amp Is Trying to Kill Me and My Girlfriend

I am not aware that "sloppy workmanship" is offensive or personal.

Maybe it's not the right choice of words. If I offended someone because I used the wrong word in english I apologize.

The solder joints on the pix would be a 1 or 2 on a scale of 10 (10 being the best). Thats plain to see (and could cause harm to the user).

Maybe "poorly" would be a better word here?

 

Let's all take a breath here.

@ArcticWhite - I think what you may be seeing here is some alarm at your outlet situation.

Here are two pictures which show my house not burning down last week after an outlet shorted. Proper wiring and circuit breakers are nothing to sneeze at. Especially in the context of mains-powered high voltage DIY gear.
The missing blade on the plug is welded into the shorted outlet. Possible cause - water may have gotten in there.

 

@ArcticWhite did you ever say if you had tried this amp in a properly grounded outlet? it kind of sounds like there's a short to the chassis somewhere but because you're using an on an ungrounded outlet, and there is therefore effectively no safety ground, there's no problem until the voltage on the chassis finds a route to ground, in this case through the guitar strings you, your girlfriend and then probably to the garage floor. If you plugged it into a grounded outlet it would probably trip the breaker if what I think is happening is correct. that being said I would be careful to you use a lightbulb limiter if you're going to test it on a grounded outlet because such a short can potentially damage your power transformer depending on what exactly is happening.

IMO, the comments about the messiness of the build are only partially relevant to your problem. Layout is a red herring, point-to-point is inherently messy looking when done by most people but it is not in any way dangerous or problematic and those messy looking amps often function perfectly with fewer oscillations and less noise than a beautiful looking turret board build. Some of the solder joints are a bit messy and can definitely be prettier, but I don't know that I saw too many cold solder joints in there and in any case those are not a safety issue just might be an issue with signal quality and noise.

The comment that is relevant, is the one that mentions all of the uninsulated leads that are exposed in there. Those are potentially a safety problem and very possibly causing the short that is giving you voltage on your chassis.

 

Electrical and other safety codes are not just a conspiracy by "The Man" attempting to ruin your day! The above pic from @tubegeek demonstrates that even when codes are followed, bad poop can happen. On the other hand, being wired properly probably saved his home from a much bigger catastrophe! That looks like an over current issue to me. Space heater or such?
Glad You're Safe!
Gene

 

Thanks! Nothing drawing current at the time except a short as far as I can tell. No problems with any of the equipment plugged in. Possibly a fault in the extension cord, but I think water causing a short is more likely given the location in the wall.

 

Re: Codes and The Man.

I actually had this thought while I was rewiring the outlet:

Is there a Big Brass Screw cabal that lobbied for the requirement that dual outlets must be separable and have two connection points? Seems like a lot of unused screws sitting inside a lot of walls to me.

 

I've got hot water, cold water, drain, BX cable and **gas** all in that shaft. It's a 125-year-old house and not everything has been done optimally over that history for sure. When I list it like that it sure sounds awful!

 

I have been hearing about some odd issues with ground fault circuits. Is it possible when there is a current draw the GFI is causing this?

 

Well, not a whole lot of options in this space, but I hear you. If it makes you feel any better the disaster outlet was taken out of the j box and moved to the end of a few feet of BX up the wall. The j-box is properly covered, only has a junction in it, and the outlet box is the right type for wall mounting. So I feel like, if I'm not completely to code, I'm at least "to code-ish." I might GFCI the outlets too - they are not very far from the washer's water supply faucets and drain.

Tell ya what - the thought of that box sparking right next to the gas line for my dryer DID scare the crap out of me, so, I'm thinking about ways to address the situation. Moving the outlets was a big improvement though.

 

OK, then that's fine, @ArcticWhite.

Your power transformer doesn't show any (significant) leak, then. That simply means that the Greek (rather Tech, in fact ) explanations I wrote are more or less met ! Grounding that kind of old devices is important, though.

More simply : while being very abuse-resistant, as a power transformer ages, its internal insulation between windings and between core deteriorates slowly but surely, notably if the transformer has been widely used and moreover overloaded.

Then the leaks appears and increases, the Xfo starts to overheat with time, even unloaded, and one of these days, there's smoke and the circuit breaker or the fuse does its job... Amen !

-tbln

 

The amp chassis is floating so leakage current from the power transformer can easily generate 50+ volts chassis-to-ground.

Do not plug a tube amplifier into a non-grounded outlet--it is not safe. There is no safe path to ground for an accidental short to the chassis.

Attach the power cord safety ground to the chassis ASAP.

 

It's a little ironic that a guy whose machine tried kill him has an avatar pic of a killer machine.