Peavey 3120 High Gain Option

These amps are switchable from EL34 to 6L6 and also adjustable bias. 

So unfortunately PV has not entered the real world yet when it comes to bias. The bias test points on these amps measure the negative bias voltage in the circuit and not the actual plate current. So the best and most accurate way to bias these amps is with a bias probe. Using the test points is a bit of a guess but it will usually get you on the outskirts of the ballpark. Please refer to the "Test Point Bias Video" which shows and describes this issue.

The cool thing about these amps is that you can use either our "Pro One" All-in-one bias probes or one of our 25.00 bias probes and a Multimeter to bias the amp without removing the amp from the cab. The probe will fit under one of the tubes while it’s in the cab so biasing is literally a 5 minute job.

EL34's, EL34II's, E34L's, KT77's, 6CA7's and 6L6GC's should all be biased between 35mA to 40mA. You can use the bias video we did on a PV JSX for reference. 

The video below explains the difference between bias probe types.