Most of the work that I have done in the past with vacuum tube and solid state electronics has been repair. So, I have ventured into the realm building. This is actually my second build (I’m still getting the bugs out of the first attempt) but I have applied all that I learned from mistakes to this build. Building from scratch is nothing like repairing. It takes time, a lot of thought and reasoning go into a build no matter how simple it may look. I have been tinkering most of my life with this hobby and I think I forgot much! My advice to anyone thinking of building an amp from scratch is read first, ask questions later. Even if you have been around this stuff most of your life (I’m 59) I recommend two good books. They are pricy but hey it is easier to learn from the other guy’s mistakes not your own! The first book is Building Valve amplifiers by Morgan Jones, and The Tab Guide to Vacuum Tube Audio by Jerry Whitaker. The audio forums have some good useful information, but you have to filter through all the assumption and guesswork. It think some of these audio forum users haven’t even used or tested most of the circuits they give opinion about. But even so, if you pay attention you can find good information in the forums. In the past, I have found that using off the shelf parts can give great results no matter what you are building. My idea here was to make a low power amp. keep it a simple as possible with nice sounding output, and I was pleased at the result.
Specs of my build are;
- Edcor XPWR193-120 Power Transformer 240V, 200mA and 9V, 4A
- Edcor GXPP15-8-8K Output Transformers used in ultra-linear configuration.
- Glassware Audio PS-14 power supply kit which supplies the high voltage and also regulated 6.3 vdc for the heaters.
- 6V6 PC boards from the nice man from China. It is a familiar circuit, the classic Dynaco 6V6 output circuit with a floating paraphase inverter . Again you’ll hear grips against it in some of the forums, but it is simple and effective. I say let your ears decide and that is all that counts. I am pleased with it. I’ve listened to some of the other tubes and I like the sound from the 6v6’s. As a matter of fact I think my next build will be a quad version with 8 6v6’s in the output!
- You will notice the controls. That is a Glassware Audio A3-Mini Stepped Attenuator which fits the bill nicely.
- Hammond 156R choke. 1.5H 200mA 56 ohms. Hammond 1444-14103 enclosure.
For more detail: 6v6 Stereo Amplifier