Power Tubes: 6L6G, 6L6GC, 7581A, EL34, EL37, 6550, KT66, KT77, KT88, KT90, KT120, and KT150. I have a Dialogue Premium HP Integrated and will be installing the KT170's. Picture will follow tomorrow. I been running KT150's since I had the Amp day one.