Tone Pot acts as Volume Control

Discussion in 'Tele-Technical' started by WrayGun, Nov 18, 2019.

  1. WrayGun

    WrayGun Tele-Afflicted

    Age:
    59
    Posts:
    1,947
    Joined:
    May 5, 2006
    Location:
    Pittsburgh, PA
    Been trying to figure this out for a while now.

    I put together a control plate exactly like this diagram. The only difference is that I used 500k pots. The tone cap is .047uf.

    Switch works, volume works, but the tone pot ignores the tone and reduces volume instead. It doesn’t go 100 percent silent, but really, really quiet.

    I have triple checked that the cap isn’t grounded out anywhere, checked every connection and checked the diagram multiple times.

    I have a 2-wire humbucker in the neck, but it’s wired exactly like this diagram.

    When I check the pickups (from the output jack), they are reading very low... like 2.4 on the neck, 4.5 on the bridge. Don’t know what that means.

    Any ideas are appreciated! I’ve found several threads about more or less the same issue, but none conclusively resolved. Thanks!

    Edit: I also have a 220k resistor in series with the neck pickup hot wire, to reduce the humbucker volume a little. If it matters.

    [​IMG]



    Sent from my iPhone using Tapatalk
     
    Last edited: Nov 18, 2019
  2. SixStringSlinger

    SixStringSlinger Friend of Leo's Silver Supporter

    Posts:
    3,151
    Joined:
    May 21, 2006
    Location:
    Space
    A tone control is identical to a volume control, with the addition of the cap. I don't know enough about wiring to tell if your diagram is correct, but assuming it is and that you have everything put together correctly, I'd guess that your cap is not working for some reason. It's not soldered in correctly, the joint is bad, the cap is bad, something.
     
  3. Deaf Eddie

    Deaf Eddie Friend of Leo's

    Posts:
    3,089
    Joined:
    Mar 17, 2003
    Location:
    Beautiful Idyllwild, CA
    Make sure the "open" lug on the tone pot is NOT touching the control plate.
     
    AAT65 and bender66 like this.
  4. BCblues55

    BCblues55 Tele-Meister Gold Supporter

    Posts:
    109
    Joined:
    Nov 11, 2014
    Location:
    Charlottesville, Virginia
    It looks like it should work. Pretty standard wiring. My guess is that one or more of the wires is hooked up to the wrong lug. And there’s no accidental solder or wire connecting the volume pot’s output lug and the lug with the cap connection, is there? That happened to me once. Sorry I can’t be of more help.
     
  5. WrayGun

    WrayGun Tele-Afflicted

    Age:
    59
    Posts:
    1,947
    Joined:
    May 5, 2006
    Location:
    Pittsburgh, PA
    Check, on the open lug.


    Sent from my iPhone using Tapatalk
     
  6. milocj

    milocj Friend of Leo's Ad Free Member

    Posts:
    3,657
    Joined:
    Aug 21, 2005
    Location:
    Michigan
    And since most humbuckers use a metal shielded cable with the outside as ground you need to make sure that it also isn't causing that lug (or something else) to ground out.
     
  7. wabashslim

    wabashslim Tele-Afflicted

    Age:
    68
    Posts:
    1,018
    Joined:
    Nov 26, 2005
    Location:
    Sonorous Desert
    The grounded tone lug came to mind but that doesn't account for the low pickup resistance readings. Are those readings with both pots on 10? If so there's a miswire or something's touching in the switch contacts, I'd guess.
     
  8. middy

    middy Friend of Leo's

    Age:
    49
    Posts:
    2,862
    Joined:
    Apr 28, 2010
    Location:
    Dallas, TX
    Post pics of your wiring if you can.
     
    LutherBurger likes this.
  9. Mark the Moose

    Mark the Moose Tele-Holic

    Age:
    45
    Posts:
    721
    Joined:
    Sep 4, 2018
    Location:
    Erie, CO
    Is it possible you grabbed the wrong value of cap?
     
  10. jvin248

    jvin248 Poster Extraordinaire

    Posts:
    8,635
    Joined:
    Apr 18, 2014
    Location:
    Lions & Tigers oh Mi !
    .

    That happens when using a '50s wiring diagram' ... layout you have looks more like the modern style but look up both and double check what you have soldered on the guitar, easy to solder to the wrong lug.

    .
     
    bender66 likes this.
  11. bender66

    bender66 Poster Extraordinaire

    Posts:
    7,219
    Joined:
    Jan 18, 2010
    Location:
    on my bike
    I was gonna say it sounds like a 50's scheme too.

    Good advice given. Hope you get it sorted.
     
  12. Peegoo

    Peegoo Tele-Afflicted

    Age:
    60
    Posts:
    1,164
    Joined:
    Oct 11, 2019
    Location:
    USA
    Yeah, a pic of the work would be nice.
     
  13. WrayGun

    WrayGun Tele-Afflicted

    Age:
    59
    Posts:
    1,947
    Joined:
    May 5, 2006
    Location:
    Pittsburgh, PA
    The pics I took are pretty indecipherable. I tested a couple of components, and I think the volume pot is defective. I checked the leads from the humbucker and it read normal, about what I would expect. The bridge pickup was reading 0.0, although it certainly is making sound. Don’t know what that means.

    I think I will take it all apart and start over, testing each component as I go. Good desoldering practice, anyway.


    Sent from my iPhone using Tapatalk
     
  14. WrayGun

    WrayGun Tele-Afflicted

    Age:
    59
    Posts:
    1,947
    Joined:
    May 5, 2006
    Location:
    Pittsburgh, PA
    Okay, I took everything apart and tested the pots, caps, resistor, grounds, etc. everything is within tolerance.

    But ... testing the bridge pickup is confusing me. At the risk of exposing my lack of skills, shouldn’t touching the meter probes on the solder lugs on the bottom of the pickup give me the most accurate reading? See photo ... I get open loop. So why was this pickup working at all, i.e., making noise through an amp?

    Second, when I test via the leads coming directly from these solder points, I get a never ending cycling through a large range of values.

    I don’t get it.

    Can I assume there’s a problem with the pickup?

    [​IMG]


    Sent from my iPhone using Tapatalk
     
  15. Deaf Eddie

    Deaf Eddie Friend of Leo's

    Posts:
    3,089
    Joined:
    Mar 17, 2003
    Location:
    Beautiful Idyllwild, CA
    Looks like a busted pickup to me.

    And yes, I have had busted pickup make noise, or at least affect the tone - my UNEDUCATED guess is it has something to do with the magnet's influence. Some kind of inductance mojo/voodoo???
     
  16. jackal

    jackal Friend of Leo's Gold Supporter

    Posts:
    2,062
    Joined:
    Jun 14, 2010
    Location:
    mojave desert
    It's marked as an 0038, but it reads and is acting like a "Nancy". Strange indeed.
     
    WrayGun likes this.
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.