How to Use a Voltmeter to Test a Tube Amp

Video Transcript

"Hello, this is Jeff Naylor from Mtroniks Engineering in Mesa, Arizona for Expert Village. Now we're going to hook up the volt meter to the biasing pins in the back of the amp. To do this we're going to use our insulated alligator clips. The center pin is going to be ground, so I'm going to use black on this one. Be very careful in installing it, that your rubber shielding covers both sides of the center pin. This will help prevent anything from shorting out. We're now going to hook up the volt meter to the center pin and the pin on the left, with the yellow wire. This is going to give us the bias reading for the tube on the left. Make sure to set your volt meter to millivolts. Now that we have these pins properly connected, we're going to plug in the amp, plug in a speaker of proper impedance. Turn on the amp and turn off standby. We must now wait a few minutes for the amp to warm up before we can test the bias. Now we're set up to test the bias in the left tube which we'll cover in our next section."