1959 Silvertone 9057A Restoration

Restoration project of a vintage Silvertone phono-stereo from 1959. I picked this stereo up for free...


Circlotron Vacuum Tube OTL Prototype

Vacuum tube audio amplifiers almost invariably use specialized output transformers to match the naturally...


Antique Tube Tester Restoration

I picked up an old PAC 954-G tube tester from a ham swap meet for $3. The previous owner couldn't speak...


Single Ended Amp Conversion

I picked up an old tube-based laboratory bandpass filter that was discarded. The challenge in this project...


All Tube 20 Watt Audio Amplifier

This power amp was an experiment in designing an all-vacuum tube circuit. We take transistors for granted...


6DQ6B Vacuum Tube Guitar Amplifier

A "Junk-box Build" vacuum tube guitar amplifier. I slapped this amp together using only parts I had...

Expert Pick
Pick of the Week

Ultralinear Single-Ended Desktop Power Amp

Desktop audio amplifier for paring with a PC. Intended for low-level music playback and computer sound...

Staff Pick

10 Watt Stereo Power Amp and Preamp

I started this project out of the need for a hifi stereo system capable of modest power output. I had...


Stereo 6DQ6B 50WPC Power Amplifier

Personal design project of a high powered stereo audio amplifier. The design is comprised of a custom...