Hi, I'm new to the board, I had a 50 Cal+ 20 years ago, had to get rid of it and recently traded an old Peavey for an other (SCORE!). I'm going to retube and am wondering if it's possible to use EL34's in this amp? I know that this is possible in some amps that are not fixed bias, but not sure if it will a 50 cal +. Thanks.