Looking for part for our outside PA System

[A_Ike]

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I am trying to track down this part for our PA sytem. It is the volume control for a section of our volleyball courts. Not sure exactly what it is called, and no local places seem to know anything about it either.

The numbers on it are TDC QC-01A and at the bottom are 0535 aCY202v0-1

Any help would be appreciated. Thanks.

[Kanga (James)]

Just a simple (old looking) potentiometer. Picking the right one depends on the resistance rating of the original.

These people might be able to help pick the appropriate value.

http://www.potentiometer.com/

[jim_long]

It looks like a 70 volt to 8 ohm transformer with a pot on top for volume control. Nothing new here, it's just the old school version.

I thinks this what your looking for.........

http://www.parts-express.com/wizards/searchResults.cfm?srchExt=CAT&srchCat=182

As far as finding the OEM replacement part, chances are not so good. So a little modification is in order.

[Dale00474]

I would try digitech.com They are an awesome supplier of electrical/circuit parts and can save you tons of cash in the end. I've used them before for Brunswick scoring repair parts like resisters and capacitors. They have a wide range of potentiometers too! =)

[SoCalTom]

Just a simple (old looking) potentiometer.

It looks like a 70 volt to 8 ohm transformer with a pot on top for volume control.

Both of you are very close, but no cigar. It's a variable transformer.

The red wire is the input, the green wire is the output, and the black wire is the common ground (or return).

On 70 volt PA systems, there can't be a regular volume control because it will put a resistance overload on the 70 volts to the other speakers. The 70 volts must be constantly at 70 volts; therefore to regulate the volume level to the volleyball zone, a line matching transformer must be incorporated. This will keep a constant 70 volts on the line from the amp to the speakers, while regulating the variable voltage to the zone speaker(s).

The cheap and dirty way of doing the same thing is to use a 70 volt line to speaker matching transformer, then install a 10 ohm variable potentiometer from the output of the transformer to the speaker. A 10 ohm pot is close enough to the 8 ohm speaker to work. Just make sure the pot is rated at 10 watts or better.

I would try digitech.com

Allied Electronics of Chicago; Ramsey Electronics and All Electronics are also good for electronic components.

http://www.alliedelec.com/

http://www.ramseyelectronics.com/

http://www.allelectronics.com/

[jim_long]

http://www.crownaudio.com/pdf/amps/138905-1_10-05_constant_voltage.pdf