[Simon] wrote in to tell us about a headphone tube amp that he just built ... [Simon’s] design adds an on board regulated power supply and a volume control for the input. Effort was made ...

With the wealth of cheap and highly integrated audio amplifier modules on the market ... tubes before — we even recently featured a DIY X-ray tube — but there’s something about [jdflyback ...

Uniquely, Dynaco sold its amplifiers in two different ways: preassembled or as DIY kits ... tube, two 7199 input (driver) ...