What could be better than a tube amplifier? How about an entire surround sound system built using tubes! Radar hacker Greg Charvat built such a beast back in 2005, and he refers to it affectionately as Frankenstein. Besides being an excellent, high-powered stereo, word on the street is that it also functions as a very capable space heater.
This is a good example of a project that has become completely out of control. At some point in the past I decided to build an all-tube home theater system (except for the DSP stuff that decodes the various Dolby 5.1, and etc signals). The result of this effort is affectionately known as “Frankenstein.” It consists of 5 class AB tube power amplifiers, tube pre-amps, and a Dolby 5.1/DTS digital signal processor, for a total of 27 vacuum tubes. Each power amplifier is capable of over 400 watts peak output. All of the equipment is mounted in a 7′ tall WW2 vintage equipment rack.
Schematics and engineering notes are available on his website, if you are up to the challenge.