Trying out a PTB tone circuit. Need some help.

Discussion in 'Tele Home Depot' started by AZkoaMan, May 7, 2017.

  1. AZkoaMan

    AZkoaMan Tele-Meister

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    I found a Premier Guitar article discussing Leo Fender's Passive Treble, Bass cicuit from his days at G&L and though it sounded pretty cool. I installed it on my Jagmaster and the results are pretty underwhelming. Part of that is my own fault (maybe all of it?) but I need some help figuring out what's going on. Here's the diagram I used:

    PTB diagram.jpg
    The author points out that this isn't the exact circuit Leo used but it accomplishes the same effect (at least as demonstrated in the author's video). I normally use a .022uF cap on the tone control of my guitars but I didn't have any around. I did have some .047uF caps and that's what Seymour Duncan always calls for in their wiring diagrams. I figured if it's good enough for them it's worth a try. The sweep of the tone treble control is WAY more dramatic than what I'm used to. Should have stuck with what I've always used in the past. My bad.

    Not my bad; when I wired everything up as shown in the diagram I found that the sweep of the treble pot was reversed. I fixed that. More bothersome is the effect of the bass control is so subtle it's almost imperceptible. This is unexpected since I used a .0015uF cap as called for and the alternate suggested values are for even less bass cut. The only thing I did differently from the diagram is I grounded the back of the bass pot to the other pots. The author says it's not necessary but I guess I just thought I would do it for good measure. I don't think that should matter but since this didn't turn out as hoped I'm putting it out there in case someone more experienced than me sees it as a problem. Also in the interest of putting everything out on the table, here's the diagram from the same article of the original G&L PTB circuit. According to the diagram Leo used a reverse log, 1 meg ohm pot with a .0022uF cap for the bass control.

    PTB old school.jpg

    If anyone can offer some tips or relate their experience using this tone circuit I would greatly appreciate it.
     
  2. richa

    richa Tele-Afflicted Ad Free Member

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    How do you have your amp set up? You might already have more bass cut that than set up there.

    Either way there's nothing to stop you using a smaller cap to raise the cutoff frequency even higher (e.g. - a more perceptible cut).
     
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  3. AAT65

    AAT65 Friend of Leo's

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    I have my Strat set up with PTB, using basically the Leo circuit.

    For me the bass cut seems to work well, using 0.0022uF and 1M pot.
     
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  4. JD0x0

    JD0x0 Poster Extraordinaire

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    Plenty of low end cut with mine. Check your wiring and cap value again
     
  5. RomanS

    RomanS Poster Extraordinaire

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    Have you tried the bass cut at volume levels higher than "bedroom"? For me the effect is more noticeable when the amp gets to start "cooking", as the bass pot will prevent too much mud, and keep everything tighter...
     
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  6. AZkoaMan

    AZkoaMan Tele-Meister

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    This I haven't tried yet. I'll give it a shot tomorrow when I have some time to play it loud. Thanks for the insight!
     
  7. waltschwarzkopf

    waltschwarzkopf Tele-Meister

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    Hi guys, I'm about to try this circuit on my guitar this weekend, it is an HSS Strat and soon to be a HSH. I want to try this PTB with a twist:

    Volume: With treble bleed, to prevent losing the high end when rolling off the volume.
    Treble: With greasebucket component to reduce only the high end without "adding" bass and making the sound too muddy.
    Bass: As shown on the original circuit. If I understand correctly, this pot is not grounded.

    What do you think?

    Currently all of my pots are 500k, so I'll try with those now and if needed change them later. I might buy no-load pots, to be able to turn them both "off" and remove them from the circuit. I might be able to get those exact capacitor values, should I consider other values?

    Note: I know that in a passive circuit there is no adding, only cutting. But you understand what I meant in the treble, right?
     
  8. jvin248

    jvin248 Poster Extraordinaire

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    I tried that one with the three different pots 250k/500k/1M and didn't like it.
    Next I tried this one
    http://tonefiend.com/guitar/two-band-ptb-tone-control-useful-easy-cheap-awesome/
    And liked that a lot. However, playing over time I found I only used it full on or full off, and only on when using distortion - so could have built it into a toggle switch or push/pull.
    So with an HH guitar I breadboarded a lot of the similar circuits (Eldred, Leo Bassy, and so on) and found that I liked the Arlo Cocked Wah tone under distortion.
    Since I only really use heavy distortion on the bridge pickup, I hard-wired the ACW to the bridge pickup. Then the tone knob dialed back reigns it in if I happen to find a need for a regular bridge humbucker tone.

    https://dl.dropboxusercontent.com/u/7440801/Guitar Wiring/Esquire3-WayArlo.jpg

    (Walt, I have a treble bleed and greasebucket on my often played Tele and both work well. Greasebucket goes in the same space used by the ACW).
     
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  9. Ripthorn

    Ripthorn Tele-Afflicted

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    I use the tone fiend circuit and I like it. The bass control has most effect when distorted, and especially when it's the amp that's distorting. I will use it to make the neck pickup not quite so muddy on certain settings. I love it, personally.

    To the OP, are you sure it's a .0022uF cap? I sometimes miscalculate the number of zeros and put in a cap that is either 10x too big or too small.
     
  10. schroeder

    schroeder Tele-Meister

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    The bass pot is definitely reverse taper in the original circuit. I use it on my parts HH Strat, and it works well. Noticeable, but useable bass reduction. I use it with a std 5-way switch that gives me some oddball half humbucker mixes. You cannot go wrong following the original G&L schem.
     
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  11. waltschwarzkopf

    waltschwarzkopf Tele-Meister

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    I just noticed that the original has the bass cap connect on both ends of the pot, but the tonefiend has the cap on the first leg and the wiper. I'm about to try them tomorrow with 500K pots just like they show. Have you tried both? Are they too different?
     
  12. AZkoaMan

    AZkoaMan Tele-Meister

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    My issues with this mod turned out to be a matter of amp settings. I was trying it out at low volume so as not to disturb the family and the effect was disappointingly subtle. I tried it out again at louder volume and I'm actually pretty impressed with the functionality and usefulness. With a clean tone the neck pickup is a little boomy and rolling off the bass just a little bit really helps a lot. With overdrive, and especially with my newly completed Big Muff clone, the effect of the bass control is very pronounced and actually pretty dramatic. With the bass rolled all the way off it's probably not a tone you would use on a regular basis but as a novelty; something to use for effect and just make some nice noise. I'm really happy with this mod.
     
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  13. waltschwarzkopf

    waltschwarzkopf Tele-Meister

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    Hi guys,
    I implemented the PTB as I wrote above, treble bleed on volume, grease bucket on tone treble and left the bass as is. The only thing is that I didn't have a 0.0015uF capacitor, so I used a 0.001uF cap. The volume and treble work great, but the bass is very subtle; I feel that the presence and overall sound drops, but not as dramatically as the treble. Also, I feel that the effect is only noticeable at the end of the pot range (for vol treb, and bass). Have you tried the circuits with LOG or LIN pots? Could this be the issue? I love the sound if the neck humbucker with the treble at 0, it is exactly what I wanted! I can't wait to try it with the tonerider I ordered.
     
  14. waltschwarzkopf

    waltschwarzkopf Tele-Meister

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    Hi guys,
    I implemented the PTB as I wrote above, treble bleed on volume, grease bucket on tone treble and left the bass as is. The only thing is that I didn't have a 0.0015uF capacitor, so I used a 0.001uF cap. The volume and treble work great, but the bass is very subtle; I feel that the presence and overall sound drop, but not as dramatically as the treble. Also, I feel that the effects are only noticeable at the end of the pot range (for vol treb, and bass). Have you tried the circuits with LOG or LIN pots? Could this be the issue? I love the sound if the neck humbucker with the treble at 0, it is exactly what I wanted! I can't wait to try it with the tonerider I ordered.
     
  15. waltschwarzkopf

    waltschwarzkopf Tele-Meister

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    I've been doinh some numbers and the resistor in parallel on the treble bleed (Seymour or Fender style) may affect the taper of the pot. I will connect it in series (Kinman style) and see if it makes a difference). Also, I'll try a different cap on the bass. The treble is spot on!
     
  16. hopdybob

    hopdybob Tele-Afflicted

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    i have this PTB in my guitar, but could someone explain what would be the effect if i would change the 500K pot that i use now for the basscut to the original 1M?
     
  17. stratguy23

    stratguy23 TDPRI Member

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    The original design of this is to use a C1M (1 Meg Reverse Audio Taper), can you use a CTS Audio Taper 1M pot for this? If so, what modifications if any need to be made? Thanks!
     
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