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Harmony H22 switch alternative

Discussion in 'Pickups & Electronics [BG]' started by TerribleCj, Jun 12, 2020.

  1. Jun 12, 2020 #1
    TerribleCj

    TerribleCj

    Jun 10, 2020
    Is there a go-to replacement for these? I know it wouldnt be original but I am missing the lever and the switch is busted to pieces in the one I just got. I've been looking for a while on reverb and ebay for a switch or even the entire harness but they are pretty scarce. I would like to put in a regular les-paul type switch in it's place but looking at the original wiring, I have no idea how to wire it up. I have the original caps that were rattling around in the body and I already added a ground wire from the bridge-piece. I'd like to have the original sounds of the bass but with a different switch. Unless someone can explain the eight terminals on the original so I can transfer to the 4-terminal style like in a 2-pickup guitar. Thanks for any insight and advice! I appreciate it! In the meantime I am playing a Heit "Professional" model, full scale I think. I've only seen one other one in the original ad that is in the Japanese Guitar book.
     
  2. Jun 13, 2020 #2
    TerribleCj

    TerribleCj

    Jun 10, 2020
    Bump, I was also reading an older post and a member used a pot to blend between the two sounds, maybe someone could help with that?
     
  3. Jun 13, 2020 #3
    Crater

    Crater

    Oct 12, 2011
    Dallas, TX area
    There's a schematic and pictorial wiring diagram of the H22 in Cadfael's Bass Diagrams, page 169.

    The switch is a 3 position, 2 pole rotary switch. The "1" position basically shunts the tone cap to ground, so it's the same as turning the tone control all the way to zero. The "2" middle switch position is "normal" with the tone cap in series with the tone pot. Essentially, it's the same wiring as a P-bass in this mode. The "3" switch position inserts a bass-cut capacitor inline, which would make for a thin bright sound, although probably less volume than the other two positions.

    You could replace the rotary switch with a Gibson-type pickup selector, HOWEVER, the middle position will be the "tone control" on zero setting. One outer position will be "normal" and the other outer position will be the bass cut.
     
  4. Jun 13, 2020 #4
    TerribleCj

    TerribleCj

    Jun 10, 2020
    Well, I found a switch with the same terminal layout as the original so I am going to give it a shot. Should be here tomorrow and I'll let ya'll know. Thanks for the link and the helpful advice Crater
     
  5. Jun 17, 2020 #5
    TerribleCj

    TerribleCj

    Jun 10, 2020
    Ok, quick update. The switch I found was way too big to fit in through the pickup hole in the body. The shaft size was fine and the terminal layout was fine but the body of the switch was gigantic. I tried a smaller, 3 position switch I had from a PRS guitar but I either wired it wrong or the switch was no good. I'm keeping my eye out for an original still and also nos vintage switches that might work.
     
  6. Sep 9, 2020 #6
    TheFretShop

    TheFretShop

    Sep 9, 2020
    I run a guitar repair shop.
    Having just fully scratch-built the guts for a Harmony H22 bass (original harness was long gone!) I though someone might need this in the future. I couldn’t find any original switches, but my diagram has detailed info for ordering the modern replacement rotary switch from Mouser. There may be better options out there, but this one worked. If you find some originals, please let me know! I wanted to do it strictly vintage, but without the old switch it didn’t really matter.

    Note 1: I used one of the switch contacts as a mount for the pickup’s ground lead, which then jumpers to the other pot grounds. It plays no part at all in the switch function - it’s just a convenient, tidy place for the pickup to live.

    Note 2: Do yourself a favor and put shrink tubing on the leads for the main .1uf tone cap, as it lives close to the output jack and a ground-out on reinstallation could cause things to malfunction.

    Note 3: This rotary switch has a solid shaft, so the original lever knob won’t fit on it. Mouser may be able to point you to a better split-shaft version of the switch. Otherwise, just preserve the original lever knob and buy a reproduction online - cheap! If you have a good drill index, drill the knob out to just under .250”, maybe .248” or so, and the knob will simply press on and work fine. Otherwise, drill out to .250” (1/4”) and if necessary use a small drop of super glue to hold the knob in place.

    Have fun!
     

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