How dangerous is a two prong amp?

[Almost Never]

I got a Silvertone 1484. It has two prongs, and the house I rent is all ungrounded anyway. If I converted it, it would only ever be useful in other places. Maybe unrelated, but the amp is also noisy, a consistent noise whether the amp controls are turned down, or even off, and I wonder if it is a ground issue. Even without a cable plugged in, it produces noise.

 

[MetalManiac]

Re: How dangerous is a two prong amp?

If you have to ask, then get it replaced.There is a dirct relationship to the "death Cap" and a replacement with the grounded 3 prong cord and removal of said cap.;

The real stigma of the "death Cap" is more due to some of the cheap old vintage Japanese amps sold here that had no power transformer, and instead used a tube and left a dangerous possibilty of a 'short to ground' , maybe its called? ..somthing to that effect...very hazardous.

 

[uOpt]

Re: How dangerous is a two prong amp?

I got a Silvertone 1484. It has two prongs, and the house I rent is all ungrounded anyway. If I converted it, it would only ever be useful in other places. Maybe unrelated, but the amp is also noisy, a consistent noise whether the amp controls are turned down, or even off, and I wonder if it is a ground issue. Even without a cable plugged in, it produces noise.

No, this is just a misunderstanding sourced in American misuse of language.

The shielding that is responsible for reducing interference is correctly called "mass", not "ground". The shielding works perfectly well whether it is connected to house ground or earth or whatever or not. It doesn't need anything absolute ground such as a connection into the earth to do the shielding against noise.

When it comes to the other part, for protection you should just put a bare wire from the chassis (there will be a screw to attach one) to something that is connected to earth, such as a heating system radiator or a water tab. That should cover many of the danger cases you can have with 2-prong amps. You can actually test this, you can buy a fuse/breaker tester in home depot that will cause a solid short between two wires and then you should see the house fuse/breaker pop. The tester thing has it's own fuse, which triggers later than the house fuse should, so that you don't cause a mushroom cloud on the horizon.

 

[GuitarStv]

Re: How dangerous is a two prong amp?

I don't think it's legal to rent a house with ungrounded wiring around here. (You really want to get on this, because any electrical equipment you plug into the wall is unprotected from surges if your ground isn't working - surge protectors need to shunt current to the ground to work.) Check your local tenant laws, and maybe ask your landlord to bring his wiring up to the standard of the late '60s. Then replace your 2 prong for a 3 prong plug. It's really not that difficult, and it's nice not to have to worry if the ground reverse switch is in the right position or if you'll get a shock.

 

[gordon_39422]

Re: How dangerous is a two prong amp?

GuitarSTV
Is right, it's illegal for devices that have as much potential as an amp does NOT to have Earth Ground. They're easy to do, and you'll save yourself or anyone else that touches your amp, should it have a malfunction.

 

[uOpt]

Re: How dangerous is a two prong amp?

GuitarSTV
Is right, it's illegal for devices that have as much potential as an amp does NOT to have Earth Ground. They're easy to do, and you'll save yourself or anyone else that touches your amp, should it have a malfunction.

Yeah, but using a manually drawn earth (ground) wire works fine, too.

The question really is whether any solid earth-connected things such as radiators are floating around there.

 

[gordon_39422]

Re: How dangerous is a two prong amp?

Yeah, but using a manually drawn earth (ground) wire works fine, too.

The question really is whether any solid earth-connected things such as radiators are floating around there.

Your right, buddy. I didn't mean to step on your toes. He could buy an earth ground-stake and enough green wire from the hardware store to do it himself and have at least 1 outlet in his house safe enough for his amp. I don't know that I'd trust a radiator's continuity.

 

[GuitarStv]

Re: How dangerous is a two prong amp?

It's possible that connecting to a radiator or copper piping would work OK as a ground. The issue would be whether or not it can transmit a huge power spike as well/safely as your typical copper wiring. I'm not sure how you would be able to safely test to be sure that this is the case.

 

[Almost Never]

Re: How dangerous is a two prong amp?

My house is ungrounded anyway, none of the outlets have a ground.

 

[uOpt]

Re: How dangerous is a two prong amp?

As I said earlier, you can buy a testing device.

Of course if you mess around with the open wires you better know what you are doing, stand on a rubber mat and have somebody with a working phone for 911 nearby.

If you can force the landlord to upgrade the wires that works better. However, earthing/grounding yourself and testing that it yourself can safe your life in the meantime. If you have non-technical family around I'd do that.

 

[Gearjoneser]

Re: How dangerous is a two prong amp?

My house is ungrounded anyway, none of the outlets have a ground.

I think you found the source of the hum. So, are all your appliances using one of these?

 

[Almost Never]

Re: How dangerous is a two prong amp?

I think you found the source of the hum. So, are all your appliances using one of these?

One of those and a surge protector, yeah. Well, basically the 360 and a few other things.

Keep in mind, the amp doesn't have a ground, it's two prong, so would that be the source of the hum?

 

[uOpt]

Re: How dangerous is a two prong amp?

Keep in mind, the amp doesn't have a ground, it's two prong, so would that be the source of the hum?

No, the earth connection has nothing to do with the shielding.

 

[hydro]

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.

 

[BrianS.]

Re: How dangerous is a two prong amp?

Had the ground switch set the wrong way, touched a mic, and BZZT. Not fun.

This is your primary danger with an ungrounded plug. Your hum could be coming from faulty, old components inside the amp. Like filter caps that don't function properly anymore.

I'd recommend getting it updated if you plan on using it on a regular basis.

 

[ItsaBass]

Re: How dangerous is a two prong amp?

Not that dangerous...but you might as well just put on a three-prong cable the next time you are in there. It's easy and cheap.

 

[uOpt]

Re: How dangerous is a two prong amp?

Folks, the specific scenario of holding a guitar and getting zapped when touching a mic is not caused by lack of 3-progn plugs or house ground. Most of the time it is caused by different ground potential.

Doesn't mean you shouldn't make the house proper and add earth to the amp of course.

 

[Almost Never]

Re: How dangerous is a two prong amp?

I can't make the house proper. Firstly, I am a renter. Secondly, I am not electronically knowledgable, or I probably wouldn't be asking.

 

[Robert Delahunt]

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.

 

[uOpt]

Re: How dangerous is a two prong amp?

I can't make the house proper. Firstly, I am a renter. Secondly, I am not electronically knowledgable, or I probably wouldn't be asking.

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.