Verify shorting plugs test procedure

[George Roland]

I ask that someone with experience with this verify that what I describe below is correct and that I'm not going to ruin sometihing this way.

I am trying to run down a hum/hiss problem, and I have read that the way to begin is to disconnect my preamp from my power amp, insert shorting plugs into the power amp's inputs and turn the power amp on with only the speakers connected. During this procedure, I should only be hearing any noise the power amp makes? Is that correct?

The amp is an ARC VT-100 Mk I. This amp has 3-pin connectors and RCA connectors. If I just put RCA shorting plugs in the RCA inputs on the amp and place nothing in the 3-pin connectors, is this a correct test for power amp noise?

To make shorting plugs, I bought a set of Radio Shack RCA plugs--these are all metal cylinders, silver in color. To make them into shorting plugs, I solder one end of a wire to the center pin connector and the other end to the shield connector so that the center pin and shield are connected. Is that correct?

Sorry for so many questions, but I don't want to damage anything, and I'd like the test to be correctly done so I can trust the results.

Thanks,

George

[Guest " "]

going back a few decades. shorting plugs for amp inputs have resistors. the resistors prevent futhur damage if there is a leak in your amp. The plugs with out the resistors are used in phono inputs.

[PrestonTom]

I certainly agree with the above.

Try a 33k resistor between the tip and the shield (1/2 watt is more than enough). It is probably best not to try it without using the resistor.

Some folks do this normally when they are using only a single channel of an amp (tube).

Good luck,

-Tom