I was in one of those "have everything that nobody needs" junk shops today, and saw a barrel, about 1/4 full of 1B5/25S tubes (in the boxes - NOS). They're nearly the same as a 1H6. If anybody wants one or all, I can get the name and address of the place for you. It's a Class A amp, but also used as a combo-detector, amp, etc. Tom - WØEAJ Denver