DC on guitar

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sunnydaze
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Re: DC on guitar

Post by sunnydaze »

Hello,

Not trying to derail the topic, but have a related question. I live in Taiwan, which uses a two prong AC outlet system. To make it worse, the wiring is not always consistent from outlet to outlet. I've made sure most of my amps on off switch is switching both AC lines to at least make sure the amp is really "off". In my apartment I also use a three to two prong adapter and use an alligator clip on a wire to manually the neutral plug the apartments to metal window frame, which is connected to the metal building frame. But outside of my aparment may not have this manual ground option.

Any suggestions aside from moving to another country?

thanks
mike
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Reeltarded
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Re: DC on guitar

Post by Reeltarded »

Hey Mike!

Do you have an electric utility box in your apartment? What floor do you live on? Here, we drive copper rods that are several feet long into the ground, then run a wire from that rod into the junction box for the actual earth connection.

If you make a 3 connection box with a single outlet in it, you could plug that into the wall, but attach the third terminal to a similar copper rod driven into the ground outside, if height isn't a problem, no?
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thejaf
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Re: DC on guitar

Post by thejaf »

I've also seen older houses with retrofitted outlets grounded to copper piping, provided the copper piping is connected to a metal (steel) water main in the ground outside the building.
sunnydaze
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Re: DC on guitar

Post by sunnydaze »

Reeltarded wrote:Hey Mike!

Do you have an electric utility box in your apartment? What floor do you live on? Here, we drive copper rods that are several feet long into the ground, then run a wire from that rod into the junction box for the actual earth connection.

If you make a 3 connection box with a single outlet in it, you could plug that into the wall, but attach the third terminal to a similar copper rod driven into the ground outside, if height isn't a problem, no?
We're on the 8th floor. I think I have my apartment covered by the manual connection to the window frame. I'm more worried about playing in other places like some of the local pubs. I've never heard of anyone getting zapped at any of the places I play, so probably not really problem. Still I worry a bit with no true neutral ground connection.

mike
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M Fowler
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Re: DC on guitar

Post by M Fowler »

Here, we drive copper rods that are several feet long into the ground
My wife talks about this all the time because her company has those grounding rods stolen all the time because people think they are copper when they are in fact steel.

Mark
DonMoose
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Re: DC on guitar

Post by DonMoose »

Reeltarded wrote:Building an amp is a dood thing. Knowing what the hell is going on in there is a rocket dood thing.
Playing guitar on an amp with a hot chassis is a dead d00d thing.

Are all the DC bites gone?
Did you measure the chassis voltage WRT the Neut and GND wires in the outlet?
Zippy
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Re: DC on guitar

Post by Zippy »

sunnydaze wrote:We're on the 8th floor. I think I have my apartment covered by the manual connection to the window frame.
A test of that would be to measure resistance between your window frame and your water pipes. In a good many buildings, window frames are floating in the wall with no electrical connection to earth.

I'd run my local artificial ground to the water supply.

Do the bars you play in have bathrooms? :twisted: I have to wonder about the look on some guy's face when he notices a thick copper wire terminating on the urinal... :shock:
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Reeltarded
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Re: DC on guitar

Post by Reeltarded »

DonMoose wrote:
Reeltarded wrote:Building an amp is a dood thing. Knowing what the hell is going on in there is a rocket dood thing.
Playing guitar on an amp with a hot chassis is a dead d00d thing.

Are all the DC bites gone?
Did you measure the chassis voltage WRT the Neut and GND wires in the outlet?
Oh yes. All measured. I might ramble like an idiot and generally confuse people, but I am very careful. (as far as i know)

lol
Zippy wrote:
Do the bars you play in have bathrooms? :twisted: I have to wonder about the look on some guy's face when he notices a thick copper wire terminating on the urinal... :shock:
ROFLMAO
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
sunnydaze
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Re: DC on guitar

Post by sunnydaze »

Zippy wrote:[quote=
A test of that would be to measure resistance between your window frame and your water pipes. In a good many buildings, window frames are floating in the wall with no electrical connection to earth.

I'd run my local artificial ground to the water supply.:
The nearest water pipes are a few rooms away, might be tough to measure, unless I tried drilling through the walls.... Wife would love that....

The window frame I'm using is butted up against one of the apartment support columns. I can measure AC from the outlet by metering one leg of AC the outlet and the attaching the other meter lead to the metal window frame. If I try that on a different metal window frame in the apartment, am not able to get a reading. Makes me think the zero volts window is floating and the other may be attached to ground somehow. But I'm not fully convinced. Note, I reversed the test leads in both tests and only one resulted in an AC measurement.
Zippy wrote:[quote=

Do the bars you play in have bathrooms? :twisted: I have to wonder about the look on some guy's face when he notices a thick copper wire terminating on the urinal... :shock:
Ha ha. Taipei is actually a large modern metropolis. Just has primitive wiring in most of the older building. Most of the newest buildings have three prong properly grounded systems. But....there are an awful lot of older buildings.
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Reeltarded
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Re: DC on guitar

Post by Reeltarded »

I hear ya. I live in 1947 too.

;)
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Structo
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Re: DC on guitar

Post by Structo »

Mike try this.

Take your meter and set it to above what your wall voltage is.

Stick one probe into one of the wall socket holes and connect the other lead to the window frame.
You may have to try both wall socket holes to find the "Hot" side.

If you get the actual wall voltage then the window frame is grounded.
Tom

Don't let that smoke out!
sunnydaze
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Re: DC on guitar

Post by sunnydaze »

Structo wrote:Mike try this.

Take your meter and set it to above what your wall voltage is.

Stick one probe into one of the wall socket holes and connect the other lead to the window frame.
You may have to try both wall socket holes to find the "Hot" side.

If you get the actual wall voltage then the window frame is grounded.
Hi Tom,

I had done that test and that's why I thought the window I'm using is grounded. I got no reading on a different window in the apartment. See my earlier post. Thanks for confirming the test works, as noted in the the earlier posts, I wasn't fully confident.

thanks
Mike
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Structo
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Re: DC on guitar

Post by Structo »

I knew a guy on another guitar forum and that lives in Tawain.

His description of the power circuits sounds very similar to yours.

Seems as if there were no building codes in place and that contractors just wired things up any which way.

Hopefully these days there is better practices in place since it can be very dangerous for shock and fire hazards.

What is your wall voltage there? 230vac?
Tom

Don't let that smoke out!
sunnydaze
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Re: DC on guitar

Post by sunnydaze »

Tom,

Taiwan is 110 V 60hZAC. Most of my amps have PT's with 120 V or 117 V primaries. So my voltages are typically a little on the low side - not necessarily a bad thing. The AC in my apartment is pretty stable and stays pretty close to 110 V.

There are building codes, just not always followed. Really depends on the age of the building. Many buildings are 30 + years old. Lot's of newer structures, too.

I've lived here about six years and Hong Kong three years before moving here. I spend a good deal of my time in Tokyo, too. Japan's AC is 100 V 50hz . Hong Kong is British style 220 V 50hz.

Mike
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Structo
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Re: DC on guitar

Post by Structo »

Cool!
So you can power any American built amp there.

Are you an ex pat or native to that area?

Your command of English is better than most here. :lol:
Tom

Don't let that smoke out!
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