DougUSMC
Perpetual Practicer
- Joined
- Feb 27, 2019
- Messages
- 879
Bias is the control that is adjusted to make sure the power tubes receive the voltage that the manufacturer thinks will sound best with the amp. On the back of PRS amps are three jacks for testing the bias, one black (common) and two red (one for each tube). This is a VERY easy thing to adjust if you have a multimeter that reads millivolts (every one I’m aware of reads millivolts).
Set the multimeter to millivolts.
You stick the black probe into the common jack, and the red probe into one red jack, adjust the bias for that tube, then do the other tube.
There’s a hole in the chassis for the screw that adjusts bias; you’ll need a small screwdriver for the purpose.
No two tubes are perfectly matched, but with the screw adjustment, you bias the tubes to an average that’s close to the manufacturer’s spec.
I don’t know PRS’ bias recommendation for the Dallas, because I don’t have one. Ask Customer Service.
Here’s a video on the process.
Ta da! Done.
Awesome, thanks!!