PRS Sonzera 20 Bias Adjustment

[PeteC4S]

New member here, does anyone have any information on biasing the Sonzera 20 combo please? I've looked on line and searched this forum with no luck. Don't need to do it now, but will in the future and given the adjustment can be done from the outside, thought I'd like to know details. Thanks in advance.

 

[Dane]

New member here, does anyone have any information on biasing the Sonzera 20 combo please? I've looked on line and searched this forum with no luck. Don't need to do it now, but will in the future and given the adjustment can be done from the outside, thought I'd like to know details. Thanks in advance.

"Power tube bias should be adjusted to 30 mV, +/- 5 mV. If power tubes are mismatched by less than 5 mV, average the two around 30. Mismatched tubes beyond 5 mV will induce noise and may cause a degradation of tone"

https://www.prsguitars.com/documents/PRS_Sonzera_Amp_Manual.pdf

 

[AP515]

What Dane said. If you buy a matched pair they will be within the 5mV window. I like the JJ's set.

 

[Egads]

As above, then listen to the amp. Slightly hotter or cooler may sound better.