brunch
08-08-2023, 10:54
I have a Yarland FV34B IV. It is using the four stock EL34 valves and has test points (1 x ground plus 2 x positive) and a pot on each side to manually adjust bias. I do not have the original manual. However, I have managed to piece together that, for at least one earlier version of this amp, the manufacturer recommends setting bias by adjusting the pot such until DC voltage measures 0.7-0.75V across the test points. When I checked mine it measured closer to 0.2V and after some cautious adjustment it now measures 0.3V, but I had to rotate the pot quite a lot to get that 0.1V change. Where do you have yours set with your EL34s?