Although I am agnostic, I could never achieve the extreme certitude of atheism it would take to become a television evangelist in order to be able to buy WAVAC SH-833 amplifiers. But I wanted amplifiers which use this Wagnerian tube. Last year I began to build my own modest 833-A SET. I run it on 1000 plate Volts through a Hammond 1642SE transformer with 4 Ohm outputs to Magnepan 0.7 speakers. I drive them through LL2765 transformers 5.4k primary and 600 Ohm secondary between the 833-A grids and ground with zero grid bias voltage causing 120 ma plate current. The Hammond 1642SE's are good for 300 ma. I drive mine with 245 globe triodes, their plates connected through the 5.4k of the LL2765's. This does not give me as much power as the WAVAC but it is more than loud enough to be too loud in my little house.
The sound is very much like the descriptions of the sound of the WAVAC but there are three things which better suit my wants: 1.) running the grid at ground potential with one side of the cathode on the 833-A eliminates a power supply and its capacitors from the signal path, 2.) I can drive it with the 245 which I prefer for its SET purity to the KT-88 which drives the WAVAC, 3.) I can build my chassis in the style of something out of a Jules Verne novel with rich green stained urethane varnished oak, gold colored sheet metal, and red velvet cushioned sides with sunken velvet covered buttons and gold upholstery tacks lining the edge. I can't buy anything like it if I could afford to.
I tried every different kind of circuit I knew of to drive it before I found the one I like best.
I think of it as a sculpture in addition to sounding far better than anything I ever heard before and I give the credit to WAVAC for proving the 833-A is the Stradivari of vacuum tubes. I know how to build a pair of these amplifiers with just under $2000 in parts so it is far-far more affordable than the WAVAC.
If I get lucky I might figure out how to find people who would hire me to build one for them, but I would want them to hear for themselves how it sounds and I would want to make certain they would not take off any protective covers which for safety contain the 1000 Volt circuits.
