Tuesday 29 January 2013

Really Simple Transistor Compressor

Request:


11 comments:

  1. No controls? Low threshold, low ratio I suspect?

    ReplyDelete
    Replies
    1. This comment has been removed by the author.

      Delete
    2. This comment has been removed by the author.

      Delete
  2. anyone built this thing yet?

    ReplyDelete
  3. Probably a bit late to comment, but I think the collector on Q4 should go to +9v, rather than ground.

    I didn't have the correct transistors, so used 2n2222s. With a 2n2907a as Q1 it sounded horrible - substituting a 2222 made a huge difference, so maybe ignore the layout and for an NPN here (there's some discussion along these lines at Freestompboxes - search for the thread on "Simple Transistor Compressor").

    ReplyDelete
    Replies
    1. Don't know what you mean by late, but your input is very welcome! True, Q4 collector was connected wrong. I updated that accordingly. I also tweaked the bias for the PNP to achieve higher input impedance as Mictester notes on FSB thread.
      http://freestompboxes.org/viewtopic.php?f=28&t=8245

      How did you fix the +9V to Q3 collector? My fix on the layout is rather crude, but it is the only difference against the original, faulty one.
      +m

      Delete
    2. Well, a full 11 months after the previous post on the thread might be a bit tardy!

      I just pulled the collector from the board and soldered a flying wire between the it and an empty hole on the bottom row, though looking a bit harder at the layout, I now see I could have done a bit of gardening with the jumpers between rows 1, 2 and 3, left Q4 in place and put my flying wire under the stripboard.

      Still, I now have a nice-sounding (if a bit rats-nest-looking) compressor: many thanks for your layout.

      Delete
  4. Hi there

    Is there any chance to get some audio or video clips for that build? I can't just build it to see if I like it unfortunately :\

    ReplyDelete
  5. Hi there

    Is there any chance to get some audio or video clips for that build? I can't just build it to see if I like it unfortunately :\

    ReplyDelete
  6. IS it possible to add a compress control to this?

    ReplyDelete
  7. Put this together, used a BC559B for the PNP and BC547C for the NPN which have similar specs to the 213 and 183 and I have a unit that is sooooo noisy it's unusable. For the life of me, cannot find the problem.

    ReplyDelete