4CX 3500 for the HT-5 and 3, (converted one, tuned another conversion) The HT-35 uses a 4CX20000D. M ----- Original Message ----- From: "Gary Glaenzer" <glaenzer at verizon.net> > which tube does this one use for a final ? > HT-20 = 8990 = 4CX20000 > HT-10 = 8989 = 4CX12000 > > HT-5 = ????