Reverse Engineering the Harmony H-191

Discussion in 'Shock Brother's DIY Amps' started by Dan Miller, Aug 14, 2016.

  1. Dan Miller

    Dan Miller Tele-Meister

    Posts:
    106
    Joined:
    Mar 22, 2011
    Location:
    Thousand Islands, New York
    Here is a photo of the cap under question in situ, in case I am misinterpreting something.

    P8260012.jpg
     
  2. tele_player

    tele_player Tele-Meister

    Posts:
    236
    Joined:
    Aug 9, 2007
    Location:
    Sacramento, CA
    Not electrolytic. The band denotes the outer foil, which should be connected to the lower impedance side of the circuit for minimum noise.
     
  3. D'tar

    D'tar Friend of Leo's

    Posts:
    2,285
    Joined:
    Jan 11, 2013
    Location:
    WNY
    That appears to me like a coupling cap with the outer foil marked as "ground". It also appears to be labeled incorrect(IMO) and the installer verified that and installed it to the proper orientation. Notice the lead on the "ground" marked side looks to be center of the cap and the other lead is coming from the side of the cap. At least that is what I'm seeing from over here.
     
  4. Dan Miller

    Dan Miller Tele-Meister

    Posts:
    106
    Joined:
    Mar 22, 2011
    Location:
    Thousand Islands, New York
    Thanks tele_player and D'tar, I learned something new today. This place is better than going to college, especially at my age.

    Presuming I survive the Arts and Crafts show this weekend (showing my leatherwork), I'll revise the schematics early next week. Parts and pieces have been trickling in for reviving this amp and building a couple of clones.
     
  5. tele_player

    tele_player Tele-Meister

    Posts:
    236
    Joined:
    Aug 9, 2007
    Location:
    Sacramento, CA
    Actually, college was great for electronics.
     
  6. tele_player

    tele_player Tele-Meister

    Posts:
    236
    Joined:
    Aug 9, 2007
    Location:
    Sacramento, CA
    You're being generous saying the installer verified it, maybe, but doesn't really matter, as it's not feeding a stage with significant gain.
     
  7. D'tar

    D'tar Friend of Leo's

    Posts:
    2,285
    Joined:
    Jan 11, 2013
    Location:
    WNY
    Generous and purely speculative indeed
     
  8. Dan Miller

    Dan Miller Tele-Meister

    Posts:
    106
    Joined:
    Mar 22, 2011
    Location:
    Thousand Islands, New York
    Here is the latest schematic. Parts and pieces are arriving both to rehab this one and to build a couple of clones.

    Harmony H-191 DIY Schematic.png
     
  9. Rjelam84

    Rjelam84 NEW MEMBER!

    Age:
    35
    Posts:
    1
    Joined:
    Jan 29, 2017
    Location:
    Cincinnati
    Hi, saw this thread when doing some homework on 191. I bought this thing at an auction for $2 over 20 years ago. Still works with all the original parts. Inside my 191 is a parts list and schematic, hope it helps.

    [​IMG]

    [​IMG]

    [​IMG]
     
    reddesert and moosie like this.
  10. moosie

    moosie Doctor of Teleocity Ad Free Member

    Age:
    62
    Posts:
    15,605
    Joined:
    Jul 18, 2010
    Location:
    Western Connecticut
    ^ Nice first post! Welcome to the forum :)
     
  11. Dan Miller

    Dan Miller Tele-Meister

    Posts:
    106
    Joined:
    Mar 22, 2011
    Location:
    Thousand Islands, New York
    Ditto and many thanks!

    If I weren't just about to leave for a month, I'd run right out to the shop!

    Dan
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  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.