1. Things you need to know about the new ‘Conversations’ PM system:

    a) DO NOT REPLY TO THE NOTIFICATION EMAIL! I get them, not the intended recipient. I get a lot of them and I do not want them! It is just a notification, log into the site and reply from there.

    b) To delete old conversations use the ‘Leave conversation’ option. This is just delete by another name.
    Dismiss Notice

SIT Power amplifier

Discussion in 'd.i.y.' started by russel, Apr 15, 2018.

  1. russel

    russel ./_dazed_and_confused

    I finally got round to finishing the Nelson Pass designed amplifier using SONY static induction transistors or power jfets. Rarer than very rare things , the 2SJ28, 2SK82 had a good reputation for sound quality, so had to be tried. Initial thoughts are it is very good, delivering a nice detailed punchy sound, maybe because it's got a low damping factor, about nine!, coz I am using it without feedback. In comparison with my previous best amplifier which is a home brew class A bipolar, the bipolar sounds a little more "hi-fi", i.e super accurate it will interesting to hear how the pass design sounds with extra feedback, supposed to sound more "neutral", so I guess it will narrow the difference between the two amplifiers.
  2. stevec67

    stevec67 pfm Member

    Interesting. Got a link to a schematic?
  3. russel

    russel ./_dazed_and_confused

  4. stevec67

    stevec67 pfm Member

    Hmm, there's quite a lot to that. I do like the way NP sets up his kits so that you solder on the resistors forst and then carry out a series of tests to ensure they are all in place correctly, before adding other things. That's smart. It's still quite a complex affair though, well done on sorting it. I'm still wrestling with a JLH, havent tested it yet. If it works the Pass L'Amp appeals, it's sufficiently way-out to be interesting in its own right, assuming it can be made with non-unobtainium parts.
  5. russel

    russel ./_dazed_and_confused

    The electronics side isn't a problem, where gloom and foreboding take hold is metalwork, as you are finding. I do manage to cut down on this by keeping circuit boards standard sizes, so I can reuse boxes and power supplies, though more difficult with the pass design as I had no control over board size, it does have a PSU which is interchangeable with my own class A design though.
  6. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Oh yes indeedy!!! Never have truer words been spoken!
  7. russel

    russel ./_dazed_and_confused

  8. iansr

    iansr pfm Member

    Whereabouts are you based Russel?
  9. russel

    russel ./_dazed_and_confused

    Southern Sweden, nearest airport is Copenhagen, so I guess not convenient to drop by for a listen.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice