12B4A SE

This micro-minidesign was found on the web and as it appeared to be super-simple as well as rather powerful, I order the tubes from my favourite NOS-supplier - Oldradioparts, Tubes and More; and the transformers from EdgarAudio, a local (Swedish) supplier of stuff for instrument amplifiers.

The main idea was to house the amplifier in a small wooden box, originally used for a dosimeter set. When the mains transformer arrived (ordered from Svebry), I noticed that it was to big for the space provided so I ordered a Hammond steel chassis instead.

To my disappointment, I had to drop a lot of voltage from the driver tube to the 12B4A's that everything inside the chassis got unfortable hot and I also had a lot of noise brom bad filtering.

This is yet another of those projects that never left the drawing board. Most of the 12B4 tubes I had, over 20 of them, were sold off, some given away and I may possible dig up a pair or two right now.

There were ideas of a simple single end amplifier based on the 12B4 and I even had one running to the Levinson schematic. However it ran really hot and showed a lot of hum, so it was scrapped.






Single Ended 12B4A Integrated Amplifier (Part 1)

Single Ended 12B4A Integrated Amplifier (Part 2)

Headphone amp