Frankenstein Vacuum Tube Home Theater

Frankenstein, A Vacuum Tube Home Theater System

Why? Because it is wrong. Tubes and surround sound do not mix.

Vacuum tube home theater sound system:

  • Built in my garage and basement
  • 23 tubes total
  • 5 class AB vacuum tube audio power amplifiers
  • One mono-block amplifier: Mono-Block Tube Amplifier
  • One quad amplifier: Quad Tube Amplifier
  • EL34 output tubes
  • Each amplifier is over 400 watts peak output power
  • 0.45% THD
  • 20 Hz to 25 KHz -3 dB bandwidth
  • 6 channel vacuum tube pre-amp/multiplexer

Summary

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.

Engineering Notes and Schematics

Caution! High voltage. Do not attempt to build anything shown here unless you have taken proper high voltage training. The high voltages present in these tube designs are deadly.

Frankenstein Tube Home Theater Photos

Photos of the vacuum tube home theater system with, without the covers removed, and under test.

System Block Diagram
Callouts for Block Diagram
Transfer Switch and Preamplifier Schematic

Power Distribution Schematic