1.) Get a simple volt/ohm meter.
2.) Detach interconnects and speaker cables from the amp.
3.) Attach a *bi-polar cheater plug to the three-prong
plug on the amplifier power cord.
4.) Set the VOM to AC volts with an approximate range
of 0-100 VAC.
5.) Remove the trim plate from the wall outlet.
6.) Plug the amplifier power cord (with cheater plug
attached) into the wall socket. Do not turn on the
amplifier.
7.) Using the VOM, measure the voltage between a point on
the amplifier chassis (a bare metal spot like a
chassis screw or some unpainted part of the chassis)
and the galvanized metal mounting frame of the duplex
wall outlet. Note the reading.
8.) Remove the plug from the wall socket, rotate it 180
degrees and re-insert it into the socket. (The plug
blades are now in new slots) Measure the voltage again
as you did in #7.
9.) Whichever plug **position gave you the lowest reading
on th VOM is the way you want to plug in the amp (or
any other device you may wish to measure, into the
wall socket.
-----------------------------------------------------------
* A bi-polar cheater plug is a cheater plug (three prongs in, two prongs out) which has had the wider (neutral) blade filed down so it will fit the narrow outlet slot when you turn it over 180 degrees in step 8. You can't buy them, you have to make them.
** If you want to ground your amp (using all three prongs) but the best position (as determined above) leaves you with the ground prong out of line with the hole in the wall outlet, get a cheater plug with a green wire coming out of it. File down the wide blade so you can plug the power cord into the wall in the most desireable orientation you determined in step 9, and then wire the little spade connector on the cheater plug to the screw that holds the trim plate onto the wall outlet (you may have to use a longer screw).
2.) Detach interconnects and speaker cables from the amp.
3.) Attach a *bi-polar cheater plug to the three-prong
plug on the amplifier power cord.
4.) Set the VOM to AC volts with an approximate range
of 0-100 VAC.
5.) Remove the trim plate from the wall outlet.
6.) Plug the amplifier power cord (with cheater plug
attached) into the wall socket. Do not turn on the
amplifier.
7.) Using the VOM, measure the voltage between a point on
the amplifier chassis (a bare metal spot like a
chassis screw or some unpainted part of the chassis)
and the galvanized metal mounting frame of the duplex
wall outlet. Note the reading.
8.) Remove the plug from the wall socket, rotate it 180
degrees and re-insert it into the socket. (The plug
blades are now in new slots) Measure the voltage again
as you did in #7.
9.) Whichever plug **position gave you the lowest reading
on th VOM is the way you want to plug in the amp (or
any other device you may wish to measure, into the
wall socket.
-----------------------------------------------------------
* A bi-polar cheater plug is a cheater plug (three prongs in, two prongs out) which has had the wider (neutral) blade filed down so it will fit the narrow outlet slot when you turn it over 180 degrees in step 8. You can't buy them, you have to make them.
** If you want to ground your amp (using all three prongs) but the best position (as determined above) leaves you with the ground prong out of line with the hole in the wall outlet, get a cheater plug with a green wire coming out of it. File down the wide blade so you can plug the power cord into the wall in the most desireable orientation you determined in step 9, and then wire the little spade connector on the cheater plug to the screw that holds the trim plate onto the wall outlet (you may have to use a longer screw).