Did own the Mk4 and to be sure I never attempted any such adjustments. And yes, I did buy mine from Brooks and brought it in for service.--The best service and waaaay; the price. A hard combo to beat in this day of "stone handed" over charging repair guys. It was this amp's lack of user biasing that sent me to the CJ 8's.
Side note;ain't this a great site where such information is shared? U-bet.
Side note;ain't this a great site where such information is shared? U-bet.