Treble bleed query

Discussion in 'Guitars in General' started by bluesdoc, Apr 16, 2015.

  1. bluesdoc

    bluesdoc Gold Supporting Member Gold Supporting Member

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    I put a treble bleed resistor/cap in my #1 and it works, but seems to have radically shifted the taper. Going from 10 to 9 is a major change in output. 8 is like half volume. I don't recall it being like that before.

    That said, it's mostly noticeable with clean tones. When using high(er) gain, it does what it's supposed to do - ie, reduces gain more than volume until turned way down.

    Is this just the way it is? I've used treble bleeds before and don't recall this radical change in taper, but it's been a long time. I'm using humbuckers.

    jon
     
  2. Fishyfishfish

    Fishyfishfish Member

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    Did you use a cap and resistor? You might have to fish around a bit to find a value that suits your needs. I got a kit from stew mac and messed around until I found what I liked and then put it in all my guitars.
     
  3. dazco

    dazco Member

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    Do you have a resistor in parallel to it? If so that can cause radical taper changes. 3 ways to fix that. 1-if it's a lowish value like 150 or 220k, raise it to 470k. Ifthats not enough try 1M. As you raise it it will lose some low end it's there to preserve but it shouldn't bee too much. 2-lose the parallel resistor and add one in SERIES with it. That will lower the cap's influence so you will not need a parallel resistor to retain lows. Use a pot or small trimmer rather than a resistor so you can adjust it till the right value for what you wanna hear. the remove it and put a resistor of that value there. (after measuring the trimmer or pot) 3-use only a cap, but if it's too thin/bright by itself, try a smaller value.
     
  4. Sparky Coldfire

    Sparky Coldfire Member

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    Hmm, that's interesting. It's been my experience that although it does affect the taper, it makes only small change in volume from 10 to 5, then much more roll off in the low numbers, 3 to 2. Can you describe your circuit and which pots (resistance and audio or linear taper) you use, I would like to know why yours reacts like that.
     
  5. bluesdoc

    bluesdoc Gold Supporting Member Gold Supporting Member

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    Let me dig into my records to see what I put in. Give me a few.....

    The bleed is from StewMac: a 150K-ohm 1/4-watt resistor (1% tolerance) in parallel with a .001uF capacitor that I put across the middle and hot lugs of the pot. I got both and am using the orange drop version.

    [​IMG]

    I'm pretty sure I've got 500K pots with switches (I do coil splitting with my RailHammers)
    http://www.warmoth.com/Push-Push-Pot-500k-with-DPDT-Switch-On-On-P732C74.aspx
    Dunno the taper, but it was fine before putting in the bleed parts.

    jon
     
  6. bluesdoc

    bluesdoc Gold Supporting Member Gold Supporting Member

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    Thanks Daz, I can play around with that. And, congrats on your 7K post count! :aok
    I believe you will get the same prize the rest of us got :jo
    jon
     
  7. dazco

    dazco Member

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    The .001uf is awful large too. I know it's an ogten recommended value, but when you are bypassing the volume pot's resistance when turned down with such a wide freq spread it will add to the issue. Try a 180pf or 250pf without a resistor at all. You'll get more of that higher range sparkle and less hi mids bypassing the pot. less need for the resistor and no taper issues and IMO it sounds better like that. With a 150k R and a .001uf cap you're really messing with taper big time. And theres 7001. :D
     
  8. bluesdoc

    bluesdoc Gold Supporting Member Gold Supporting Member

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    I can't find my box of caps... :( (we moved 2 years ago..... oy) Radio Shack has a 100pf cap. That's the only pf cap size they have, so I bought it. Mmm, it's a 2 pack, so I could put them in parallel and it'd be = 200pf, right?
    Warmoth got back to me - it's audio taper, fwiw.

    Just about to break out my Weller ---->>

    jon
     
    Last edited: Apr 16, 2015
  9. bluesdoc

    bluesdoc Gold Supporting Member Gold Supporting Member

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    Done. Better!! Thanks guys.

    edit - maybe I'm delusional, but with volume and tone controls dimed, it seems like there's more treble than before. Delusion? I feel like I need to dial back my amp treble a bit. ???

    jon
     
    Last edited: Apr 16, 2015
  10. dazco

    dazco Member

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    It's only possible if the pot isn't closing the in/out connection completely when on 10. In other words, if theres resistance between the input and output lugs so they are not fully closed. But there has to be enough resistance for the cap to have an effect and that would mean enough to make the pot considered defective. With the pot properly working theres no way that can happen. It would be the same as taking a cap and soldering it's 2 legs together than soldering that to any point in the signal chain.
     

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