Ricotjuh - if what you want is adjustable fixed bias just so you can use non-Mesa branded tubes, it seems either of those two examples are on target.
Since it appears your experience is rather limited, perhaps you would be best served by keeping it simple and abandoning the notion of autobias, which as you've read many times in replies is somewhat antithetical to guitar amp operation, other than experimentation.
Since it appears your experience is rather limited, perhaps you would be best served by keeping it simple and abandoning the notion of autobias, which as you've read many times in replies is somewhat antithetical to guitar amp operation, other than experimentation.
The most important condition for the correct function of the OPT (power tube end output transformer) is to ensure complete symmetry of the power tube currents. This ensures a long service life of the tubes and the AB modules can do it 100%.
As for the final sound of the guitar amplifier, then when the first condition is met, the color of the sound depends on the setting of the bias power tubes.
There is a trimmer in AB modules that can be used to set bias. The trimmer can be unsolder on request and a potentiometer can be instaled, which is accessible on the amplifier. All you have to do is determine to what extent the bias potentiometer should be regulated so that the power tubes are not overloaded.
As for the final sound of the guitar amplifier, then when the first condition is met, the color of the sound depends on the setting of the bias power tubes.
There is a trimmer in AB modules that can be used to set bias. The trimmer can be unsolder on request and a potentiometer can be instaled, which is accessible on the amplifier. All you have to do is determine to what extent the bias potentiometer should be regulated so that the power tubes are not overloaded.
Bias and overload are very different things.
Complete symmetry does not affect tube life, and is not always the goal in musical instrument amps.
This AB does not do that. AB compares in a very long time constant. It still averages the signal during regulation. That's why the setting is so stable. The description is on the website www.audioamp.eu.