Showcases the author's build of tube amplifiers, pre-amplifiers and restorations of tube radios.

Description and photos of multi-amp PCB with three integrated amplifiers each PCB and 24 dB/Octave Linkwitz-Riley Electronic filters. Configurable as a bi-amp or tri-amp.

DIY guitar site that features guitar tube amps, pedal building and related projects.

DIY site specializing in tube audio, vintage style guitar amps, mad science and all around DIY hooliganism.

Describes a few tube amplifier projects including schematics and descriptions of the circuitry.

A web community (message forum) for the discussion of DIY Audio.

Marco Rutz shares his experiences and projects in design, acoustics and recording. Personal observations, current and past projects, photo gallery, and high-end systems are showcased.

Information related to vacuum tube circuits and techniques.