How dangerous is a two prong amp?

[GuitarStv]

Re: How dangerous is a two prong amp?

In theory it's as dangerous as the wattage rating. As soon as you can, get the outlet grounded. They make ground adapters that screw into electrical outlets using the screw on the front plate: that's a little better than nothing, but I still wouldn't use it long. Take this from someone who has been there, done that. I am certified by the USAF to work on aircraft electrical components.

You mean the wattage rating of the transformer, not the wattage rating of the amplifier right? My 18 watt Traynor has a transformer that pulls 75 watts. There's also potential failure of the death cap to worry about . . . in that case your chasis just gets electrified with straight up wall voltage.

 

[Robert Delahunt]

Re: How dangerous is a two prong amp?

You mean the wattage rating of the transformer, not the wattage rating of the amplifier right? My 18 watt Traynor has a transformer that pulls 75 watts. There's also potential failure of the death cap to worry about . . . in that case your chasis just gets electrified with straight up wall voltage.

Yes but I pick the wattage rating of whichever is higher because I'm a bit paranoid with that. I used to get shocked in Japan in the church there between the microphone (XLR cable wired to sound system in back) and my guitar because my amp wasn't grounded. That was the Twin Reverb, too ('72 silverface). Good thing we got that fixed.

 

[uOpt]

Re: How dangerous is a two prong amp?

Yes but I pick the wattage rating of whichever is higher because I'm a bit paranoid with that. I used to get shocked in Japan in the church there between the microphone (XLR cable wired to sound system in back) and my guitar because my amp wasn't grounded. That was the Twin Reverb, too ('72 silverface). Good thing we got that fixed.

This should have been an actual defect, not just a lack of earth.

 

[Lewguitar]

Re: How dangerous is a two prong amp?

I used one of these recently. GREAT amp, sounds amazing. Had the ground switch set the wrong way, touched a mic, and BZZT. Not fun.

Nope. Not fun. But it's happened to me dozens of times. Still here. Based on me still being alive, I think the danger of death is exaggerated.

 

[uOpt]

Re: How dangerous is a two prong amp?

Careful, folks. There are several possible reasons or the mic zap, some of which put just a voltage differential but others put the full A/C voltage.

 

[Almost Never]

Re: How dangerous is a two prong amp?

Allright, time to repeat two things:

1) the shielding has nothing to do with earth or 3-prong plug. If you got buzz/noise the lack of it is not the reason

2) you can vastly improve the safety by manually laying an earth wire from the amp chassis to a grounded thing such as a water tap or a heat radiator. The amp will have a screw on the outside prepared for it. That's what it is for, they weren't stupid back in the day.

What you landlord does might or might not be illegal in your area.

I tried the amp at home (family home, not ungrounded apartment) and it had no noise. At the apartment, it does.

 

[Robert Delahunt]

Re: How dangerous is a two prong amp?

This should have been an actual defect, not just a lack of earth.

But when they ran a ground for my electrical outlet, the problem went away.

 

[uOpt]

Re: How dangerous is a two prong amp?

I tried the amp at home (family home, not ungrounded apartment) and it had no noise. At the apartment, it does.

Is that still with the 2-prong plug on the amp?

Or did you use a 3-prong with an adapter in the apartment?

Was it 50/60 cycle noise or random buzz?

 

[uOpt]

Re: How dangerous is a two prong amp?

But when they ran a ground for my electrical outlet, the problem went away.

Was that with a 2-prong or 3-prong amp then?

 

[Lazarus1140]

Re: How dangerous is a two prong amp?

A 2-prong plug should never be taken internally. Doing so may cause a person to be ungrounded in all his ways and suffer from bi-polarity.

 

[Robert Delahunt]

Re: How dangerous is a two prong amp?

I've never messed with the amp: it's always been 3 prong. The outlet was 2, so fixing it was running the tab on a "cheater" plug to a real earth ground.

 

[Lewguitar]

Re: How dangerous is a two prong amp?

Very important to use the right three prong cord...especially if someone you don't know insists on sitting in with your band.

 

[Robert Delahunt]

Re: How dangerous is a two prong amp?

Very important to use the right three prong cord...especially if someone you don't know insists on sitting in with your band.

LOL!

 

[uOpt]

Re: How dangerous is a two prong amp?

None of this is a problem as long as you don't get zapped.

 

[BloodRose]

Re: How dangerous is a two prong amp?

Very important to use the right three prong cord...especially if someone you don't know insists on sitting in with your band.

LOL! This is brilliant!!


How dangerous is a two prong amp?? Not as dangerous as a Green Manalishi with a two prong crown!!

Sorry, I just couldnt resist saying that!!

 

[Artie]

Re: How dangerous is a two prong amp?

2-prong outlets are grounded. Take a look into your breaker box. The "3rd" prong and the neutral are all connected to the same bus bar. Back in the days when the electrical code folks were trying to decide whether or not to require 3-prong wiring, there was much debate and dissent. The final decision was far from unanimous. We got 3-prong outlets by virtually one vote. There's nothing dangerous about a 2-prong cord. However, it is somewhat important to plug it in with neutral on the chassis.

 

[Robert Delahunt]

Re: How dangerous is a two prong amp?

2-prong outlets are grounded. Take a look into your breaker box. The "3rd" prong and the neutral are all connected to the same bus bar. Back in the days when the electrical code folks were trying to decide whether or not to require 3-prong wiring, there was much debate and dissent. The final decision was far from unanimous. We got 3-prong outlets by virtually one vote. There's nothing dangerous about a 2-prong cord. However, it is somewhat important to plug it in with neutral on the chassis.

You say that now, but realize that in Japan everything is 2 prong. But that didn't prevent me from shocking my lip against the microphone. Wiring my third prong to an earth ground did prevent the shocking. My amp had recently been repaired by Austin Amplifier so I don't think it was my amp.

Electrically speaking, I know what you mean, but sometimes a separate ground isn't necessarily a part of the current flow.

 

[uOpt]

Re: How dangerous is a two prong amp?

You say that now, but realize that in Japan everything is 2 prong. But that didn't prevent me from shocking my lip against the microphone. Wiring my third prong to an earth ground did prevent the shocking. My amp had recently been repaired by Austin Amplifier so I don't think it was my amp.

Electrically speaking, I know what you mean, but sometimes a separate ground isn't necessarily a part of the current flow.

One reason for the guit-to-mic shock is *correct* rounding on part of the guitar and the mic but that the guitar amp and the vocal systems are plugged into outlets where there is significant difference in ground potential. There can easily be 50V or more differential and each outlet alone works fine, but if you bridge the two ground you get zapped.

This can easily be tested by moving the guitar amp to the outlet that the vocal system is on and/or with a multimeter.

It is one of the more harmless shock scenarios but still a primary reason why I think grounding the strings is life-threatening nonsense.

 

[Robert Delahunt]

Re: How dangerous is a two prong amp?

Then I'll agree to disagree politely and respectfully, because I cannot in good faith ever recommend that anyone cheat or disable a ground (third prong).

Sent from my GT-P3113 using Tapatalk

 

[uOpt]

Re: How dangerous is a two prong amp?

Then I'll agree to disagree politely and respectfully, because I cannot in good faith ever recommend that anyone cheat or disable a ground (third prong).

I said disconnect the strings from the guitar ground (and shield instead to control interference). Not to disconnect the amp from ground, man. What the heck?