How I "safely" use 2-prong amps until I change to 3-prong!

[ParthaD]

parthad you opened a discussion about a dangerous subject.
i am not name calling and i stopped the electrical game for four years and went to goldsmiths university london to receive bmus(hons) but just because i have a degree does not make me more cleverer than anyone else
but when it comes to electrical safety i 100 per cent know what i am talking about and you do not
my only concern is for the people with a two pronged plug thinking that it is safe when it is downright dangerous.

....no Clydey not "cleverer", but your BMus degree does qualify you to talk more authoritatively about western music and tone than me perhaps. Never said it is safe, just that it is 1000 times "LESS RISKY", than getting in your car and driving to work!!!

[ParthaD]

This is my technical analysis of the situation as an engineer. I offer it for reference to anyone interested, but I don't want to imply that it's valid. I concede that the risk of getting electrocuted by ungrounded equipment is small, but there's simply no point in taking it, because it's so easy to make it go away by fixing up a ground! Like a previous poster said, 6 dollars and half an hour to fit it: that's cheap insurance.

Small.... what I've been trying to say all along!

Now about the 6 dollars... there are many who consider even that safety mod as taking away the antique value and collectability of a 1950s or older amp. These are the guys I am someday hoping to sell some of these vintage amps that I am picking up and fixing these days.

[guitician]

Amp's could use an isolated input transformer and be even safer. Like that poor guy that Steve mentioned; he would not have died playing an amp with one.

[Gibsonman63]

I fail to see the point of all of this. I have done a fair amount of commissioning work myself. This a known risk with known corrective action. If we were on a start-up, there would be no debate. The unknown risks cannot be quantified, even if you can approximate the known risks.

I don't know how fast you type, but I could have already changed it out by now and be debating the best type of coupling capacitors or what color Tolex sounds best on a Marshall.

[clydey]

steve class 11 equipment does not have any exposed metal fittings this is where the double insulation comes in and if it does not have the square within a square symbol it must be earthed.
certain exceptions for example a light ceiling pendant.
when an earthed chassis becomes live or even has leakage to earth the rcd disconnects the supply with 2 ranges of values in time depending on the amount of current in milliamps flowing to earth. these time values in milliseconds cannot be achieved if the equipment does not have a proper earth wire connected thus making the equipment unsafe ie touching the chassis(under fault condition) and an earthed piece of equipment.
but in reading your posts i believe you understand the dangers very well
cheers

[Steve Conner]

Amp's could use an isolated input transformer and be even safer. Like that poor guy that Steve mentioned; he would not have died playing an amp with one.

Then they would be IEC Class II, what we used to call "double insulated", like a lot of TVs, VCRs, hi-fi sets and so on. This would be perfectly OK if the transformer and internal mains wiring was built to Class II standards.

steve class 11 equipment does not have any exposed metal fittings this is where the double insulation comes in

That's what I'm saying. An old Fender with a 2-prong cord is not the same as a modern VCR with a 2-prong cord, because the Fender doesn't have double insulation. The VCR can still be Class II, even though it has phono sockets for plugging stuff into, that count as exposed metal fittings by any rule. The VCR's video in/out sockets are separated from the mains by two layers of insulation, but the Fender's guitar jack is separated from the mains by .01" of mouldy kraft paper.

there are many who consider even that safety mod as taking away the antique value and collectability of a 1950s or older amp.

Well, that is a serious point. When you get into hardcore collecting, they want the original capacitors in there! I've seen 1950s electrolytics explode in a horrific goopy mess, and I'd be just as scared of that as I would of the 2-prong mains cord. I can only assume that these guys either don't power their pieces up, or do it with a fire extinguisher handy. For an amp that's intended as a "daily driver", I'll say it again, remove the death cap and replace the power cord with a grounded one!

[BackwardsBoB]

You've seen the posts:

"My mom got me a PV Classic for Chrismas. Whatever. What can I do to make it sound like Engl? Can I just stick in bigger tubes?I herd that if you bias it up it will better sound. How do you do that. I need it to modified. I play mostly Death by Pancakes and Gritty Pits."

Sometimes a bit of unwarranted paranoia is a good thing.

I must admit, I never met anybody who killed themself working on a tube amp. It would be pretty embarassing though, so maybe they just don't talk about it.

What percentage of coroners call the guy with the "electrocuted" list when they process a carbonized corpse?

[dombrowskim]

If a customer of mine wants to keep an original two-wire line cord, I add a chassis mounted, external ground wire that they plug into the U-ground on a receptacle. That way they can remove it and say it's original!

[guitician]

Here you go.... Take a 3-prong plug and fit it with the third conductor wire of suitable gauge and insulation to a large battery (jumper cable type) clip, then clip it to the end of your guitar cable plugged into the amp. Amp stays original and your shock danger is gone.

[txstrat]

I don't like - and have never liked - the calculations of something that would or could happen, or will or will not happen. Statistically you win a major jackpot once in eighty years - how long have you been playing?
Ever heard of the statistician who saw an old lady eating soup. He went out and calculated the amount of soup she would eat until the end of her life. What he didn't see was that the lady finished her meal pushed the plate away and said: Ugh, that was disgusting. I'll never eat soup again.
See what I mean?
Besides, an essential part of human thinking is, that everything only happens to the others. I believe the poor people in the latest plane crash thought so too.
I'm not saying: don't nobody fly anymore but coming to the matter of this thread I think almost everybody here wants everybody to be on the safe side.
If I were a collector I would leave the amp as it is and don't use it. As a player I wouldn't take the *risk* that electrocution could hit me too - not just the others.

[R.G.]

I find it somewhat amusing that someone would claim to be an expert at evaluating risk, and experienced in the USA legal system and also advocate leaving some safety measure out.

Safety standards are not about calculating statistical risks, particularly. They are about legal liability, or have become that. From what exposure I've had to the US legal system, someone can be held liable for an event if they had any contact with the situation or its precursors, and knowingly did nothing to stop a forseeable bad outcome.

Partha, I very much enjoyed your espousal of your risk analyses. I hope you get to enjoy your analysis of the risks as well. And I very much hope no one is ever shocked, injured or killed by any amp you worked on.

However likely or unlikely any bad outcome which may happen, there is legal precedent to take YOU to court as a knowledgeable professional (you've publicly claimed that much) who willingly left a known, recognized electrocution hazard in place and in fact asked for ways around having to do anything about it, including putting into public view your opinions in this forum. And this against the public advice of people who actually do work in the field that you've fluttered over to.

I do know some attorneys (OK, I'm embarassed to admit that, and they're embarrassed to admit they know me ) and I've seen both how they think and read some juicy court case synopses they provided. A good attorney, given only the material you've typed in here could come up with willful negligence, and a DA looking for a case that week could come up with probable cause for some of the manslaughter laws, I think. Even if you aren't found liable or guilty, your defense fees could be massive. I hope that doesn't happen to you, but as you say, if the risks are small and you want to assume them, so be it.

Egad, I know lawyers who would salivate reading this...

You might consider making any buyers of the stuff you sell sign off that they accept all risk of your NOT fixing the exposures. It might help in a legal sense.

Of course, as you flatly admitted, you're a troll.

This topic sure gets some people riled up exactly as I had expected!

[ParthaD]

Well...

... I appreciate your response RG.

I have been sued many times over professionally - goes with the territory of risk analysis. That has taught me to take emotion out of the picture and dwell on facts alone. I invite anybody to dispute the numbers or logic used in that analysis. Also I invite anybody to show me any language in that post anywhere where it was recommended by me that OTHERS do what I claimed to have done OR that it is SAFE to do that! Because neither have I recommended nor have I said it is safe, the post started out with a disclaimer and in the last portion of it Steven who was a vociferous opponent of that whole viewpoint but in the end (regardless of what he thinks of me) he did state that his engineering analysis did indicate that the risk was small which is what I'd been saying all along. In saying that, did he also become a target of litigation?! I guess if that were true then he is safe in Glasgow for now!

On the other front, next time you (and other respected readers of this forum) go to Guitar Center please do take a look at the section where vintage amps are kept. I did do that when this thread was was still very hot and I found that almost EVERY one of those vintage amps including mid-1960s Champs, BFs, etc were all STILL 2-prong. GC had NOT changed them over to 3-prong and there was no visible notice on them either, that they posed a serious safety hazard of electrocution! These were amps selling at 1800 all the way to 5000!!! I think if this is as much of a safety hazard as it has been made out to be, then GC is a MUCH bigger litigation target than poor me! But then even McDonalds got sued because somebody spilt hot coffee on their lap, and in Florida somebody got sued because somebody trespassed into their house and hurt themselves falling into an empty pool!!!

Enough said...

[Enzo]

DISCLAIMER: By no means do I recommend anyone do this, nor do I recommend anyone doing anything unsafe.


But if you still want to play in traffic, here is the best way to do it.

First, carefully watch the traffic light. When it turns red for your street, then the cars should stop moving. At that time, you can frolic in the street with just the barest minimum possibility of getting run over.

Exercize caution by watching the other direction traffic light. As it turns to amber, I recommend you leave the street in anticipation that your side will turn green soon and cars will again start moving.

Watch closely and you will detect a pattern to the traffic. By carefully timing your play, you can successfully avoid being run over while still playing in the street.

Please only do this yourself alone, DO NOT get your younger brother to play in traffic with you. Well, unless he really is getting on your nerves.


Next week we will cover how to obtain alcohol as a minor, WHICH I DO NOT RECOMMEND MINORS DO.

[Chuck H]

DISCLAIMER: By no means do I recommend anyone do this, nor do I recommend anyone doing anything unsafe.


But if you still want to play in traffic, here is the best way to do it.

First, carefully watch the traffic light. When it turns red for your street, then the cars should stop moving. At that time, you can frolic in the street with just the barest minimum possibility of getting run over.

Exercize caution by watching the other direction traffic light. As it turns to amber, I recommend you leave the street in anticipation that your side will turn green soon and cars will again start moving.

Watch closely and you will detect a pattern to the traffic. By carefully timing your play, you can successfully avoid being run over while still playing in the street.

Please only do this yourself alone, DO NOT get your younger brother to play in traffic with you. Well, unless he really is getting on your nerves.


Next week we will cover how to obtain alcohol as a minor, WHICH I DO NOT RECOMMEND MINORS DO.

Bwahahaha!!!!! LOL

[ParthaD]

That was funny!!!

Enzo, I have learnt the most on this forum from reading quite a "few" of your 10000+ posts including your keen and "sharp" sense of humor!

You may not even remember this now, but in 2006 when you were just starting out on MEF you had stated in a post that you were going to finish what you were doing in order to go see "naked cheerleaders"!

That post

I don't think anybody saw you as being serious about doing that, nor do I think anybody protested that you were setting a bad example for "impressionable children" even in jest!!!

After reading this thread I don't think any of the readers of MEF are going to run out and change their 3-prong to 2-prong because some loony (that would be me) on MEF thought it was ok to do so!

best regards!