Yes I was considering the 300B version but opted for the EL34.I sold my MKII with the stock tubes keeping my vintage tube complement.Tube rectifier is a 1945 RCA 5AR4GY with hanging filament,power tubes are Genalex KT77's,and signal tubes are Tungsol JAN 6SL7WGT.I have spent hours auditioning several brands of vintage and current production tubes with my MKII and in my opinion for this amp the aforementioned tube complement is the most desirable.Power cable is the Silver Ghost by Mark Tunis and interconnects are Mad Scientist.Will update on my impressions after 100 hours.