Saturday, April 10, 2010

Design your own vacuum tube audio amplifier.

Ever wonder how you could design your own vacuum tube audio amplifier?


  1. Nice, solid design. Engineering with heart, tradition and warmth (literally).

    I wish I had had the possibilities twenty years back when I was still a pupil and read my old flea-market-bought Funkschau magazines from the '70s and '80s.

    Best wishes from Hamburg

  2. Great skills. The home theatre is fantastic. I don't profess being able to follow everything, as I just started in electronices last year, self-taught at 62, but I think I receognize good work. Thanks for the peak.

  3. Hi Ulrich,

    Yes it does get warm, literally! I like to joke that it is energy efficient because it heats my house and provides entertainment at the same time :)

    Hi Mathman,

    It's great to hear that you have started the hobby of electronics. I think you can go along way in teaching yourself. When i was in high school i built a radio telescope receiver by teaching myself.

    Good luck.


  4. FYI

    If you find this stuff interesting, Audio Express Magazine (formerly Audio Amateur) is free online:


  5. Great pdf, Gregory, thank you for your work!

    "energy efficient because it heats my house and provides entertainment at the same time"

    Yes, it is true and there is another factor - audio waves sounds much better in the filament heated air :)

    p.s. One trick: "The Great Hum Killer"
    If you insert low resistance powerful resistor between the middle point of filament transformer winding and the ground wire, you should to apply some (just a little) positive voltage to the heaters.
    It should provide complete hum suppression, especially in the auto-biased circuits.


  6. Wow what a nice idea and implementation

  7. Do you still have the slides? I'm very interested to see them, but they appear to be offline...

  8. Hi Kris, i've updated the links you should be good now.


  9. Hi,

    I am really enjoying this read, it's very well done. Can't wait to get my tubes and start building.

    I was wondering if there was a link to the excel files as it looks like they would be very useful. I suppose I could make them my self but it would save a lot of time.

    Thanks for this,