treble bleed issue

[12AX7]

This is really puzzling to me. First let me say i am intimately aware of how treble bleeds work, i've tried every imaginable way including resistors of values from 220k to 1M in parallel with them to keep lows, resistors or a pot in series to change the amount of effect they have, etc. But i have a guitar which mystifies me. It's a MIM '72 thinline tele RI with ash body and maple neck and 2 fender wide range humbuckers. The pickups plain sucked, so i modded them radically. Then I ended up tossing them in favor of some boutique WRHB's and they sound fantastic by comparison. I have tried 250 and 500k for volume settling on 500. I'm telling you all this so you understand what i have to say next is NOT because of the way it's wired or the pickups or anything like that because this issue has been with this guitar from the start with the 3 different pickup scenarios and various wiring including every imaginable treble bleed circuit imaginable. In fact i soldered wires a few inches long with gator clips in the end and had them hanging out so i could clip in any treble bleed circuit and value i wanted. So heres what i'm getting at. In all my years, and i have used treble bleeds in every guitar i have ever owned, i have never had this happen....no matter what values or circuit setup i use, there is so little treble bleeding thru it never gets very bright, and i'm now going straight cap with no resistors in any fashion. Just a cap across the in/out lugs and no valuse from 50pf to 1000pf gets me much brightness, and the neck pickup actually stays so muddy i have to turn down to about 3 before the lows are gone. It's not the pickup either because i have the exact same one in the bridge, so the lows are just from the neck position which is apparently very healthy in this tele !

Anyways, but the time i get it down to about 5, THEN it becomes harsh due to all that treble which of course is more apparent at lower settings. But the odd thing is as i turn down between 10 and 5 the tone hardly changes over no treble bleed. Usually it's night and day between treble bleed and no TB by the time you get to about 7. With thie tele it's barely noticable. And lest you think it's because the pickups don't have much brightness, on 10 they cut like a knife. So i just don't get it and have looked at every angle to try and understand what could be causing this. All new electronics since it was new and it's the same as it was then. (I put a TB in it day one as i always do)

I know there are a lot of really bright people here that understand electronics much better then me so hopefully someone will have an idea what i might try. The problem here is with other guitars there so much treble with certain cap values when you don't use a resistor that I use various methods with resistors or pots and cap value to tame it and i can then get just the right amount and frequency i want to bleed thru. With this theres so little to work with i can't get the rolled off tone perfect like i usually can.  Any ideas?

[jjasilli]

Are you using audio taper or linear taper pots.  If audio taper, try using linear taper instead.  

Otherwise:
1.  Lets put aside your treble bleed mod for now.  The heart of the guitar's tone control circuit is the nominal value of the pots in conjunction with the value of the main tone cap to ground.  It's a shunt cap which bleeds treble to ground.  You don't state the value of this cap.  The value of this cap (in conjunction with the nominal R value of the pots) sets the frequency at which treble starts to bleed to ground (the corner frequency).  The nominal value of the vol pot affects treble also, because treble frequencies bleed to ground easier than do lower frequencies.  Hence, a higher value vol pot prevents treble from shunting to ground through lugs 1 & 3.  The setting of the tone pot determines how much treble signal gets shunted to ground through it, at and above the corner frequency.  This whole enchilada is called a treble bleed tone control, and is the simplest form of tone control circuit.

Without stating the value of these components along with the DC resistance of the PU, it is  not possible to address your problem specifically.  Also lots of info is available at www.guitarnuts.com.  You may wish to post a schematic.

2.  "Treble bleed mod".  This is merely an accessory to the main tone circuit.  You have to get the main circuit right first.  This mod is a small value by-pass cap across lugs 1 & 2 of the vol pot, possibly with a resistor in parallel to that cap.  Why have this mod?  The issue it addresses is this:  as the vol pot is turned down, more treble bleeds to ground through the vol pot.  See Item 1 above.  Remember that a vol pot is a variable voltage divider which consists of a series resistance & a shunt resistance.  At -0- on the dial the shunt resistance is -0-, so all signal bleeds to ground.  When turned up a little, lo frequencies are the first to get lifted from ground, but treble still easily bleeds though the pot.  As the pot is turned up further, at some point, the vanishing treble effect disappears.  

This might be considered to be a "feature" or a "bug".  As a feature: in a live performance, turning vol down reduces treble and better blends the guitarist into "the mix".  As a bug: some people may prefer to keep vol & tone functions separate.

Solution:  the treble bleed mod.  As the vol pot is turned down treble passes more easily through the -0- impedance of the added bypass cap in the signal path, rather than through the shunt resistance to ground of the vol pot.  Now, at low vol settings, more treble stays in the signal path where it encounters no impedance, so it does not bleed through the pot's shunt resistance to ground.  That's normal and explains why the mod has little to no effect from 5 - 10 on your dial.

[12AX7]

Thanks. But i'm very aware of how a TB circuit works and i use them in every guitar i've had forever with the same setup. Every guitar i own and have owned for decades, first thing i do is i disconnect the tone pot, so no tone cap, ad a treble bleed, and i always put CTS audio taper in them. If i put a 250, 500, or 1000pf cap on the volume in any other guitar i have to use a parallel'd resistor or a series resistor or pot to cut some of it down or it gets so thin and bright it's unusable. Thats why i asked why is it happening to this guitar. Same pots, same TB same everything. The only thing i can figure is it has something to do with this TYPE of pickup. Maybe something really odd like the metal cover with 3 exposed poles on each coil, one coil's exposed poles on the E A and D while the other on the trebles. I dunno. I just wish i could figure this out but nothing makes sense.

I love this guitar and it's capable of so much more if i could figure out how to make a TB in it work the way it does in other guitars. I hate missing all that potential that could be so much better once the volume leaves the 10 position. (which is where i am more often than not)

[sluckey]

Have you tried another guitar cable?

You are aware that the treble bleed cap operates exactly the same as a bright cap on an amp's volume control?

[12AX7]

Have you tried another guitar cable?

You are aware that the treble bleed cap operates exactly the same as a bright cap on an amp's volume control?

Yes and yes. Well, yes to the TB on a amp, but the cable doesn't matter since my other guitars all have the same setup and they work the way they should.

[sluckey]

but the cable doesn't matter since my other guitars all have the same setup and they work the way they should.

The cable does matter. It has a fixed shunt capacitance that may react differently with different pickups, vol. pots, etc. It may not cure your particular problem, but it is a factor that is easily ruled out.

Your description indicates to me that the bleed cap is doing what it is supposed to do, but it's just not sounding as good to you as your other guitars. You may not get much satisfaction with those particular electronics.

Using a linear volume pot will change the point at which the treble bleed begins to be audible as you turn down from max. But using a linear pot may have other effects that you don't like.

[12AX7]

Yes, cables DO make a difference but in all my years this is the first time i've gotten this reaction from a treble bledd and all my other guitars are fine with this cable. So all i'm saying is that rules the cable out. I think u r right in that i just won't be able to get the same effect out of this guitar.  It just surprised me because it's never happened b4 and i have been doing this to countless guitars for years. The good part is the tone sounds good down to about 6. Unfortunately if i set the amps amount of drive to where i want it when the guitar is on 10, by the time it starts to get real clean at about 4-5 , thats when it starts getting nasty. So my clean sound suffers. With my others i can use resistors/pot in series so that when it gets down there to where it's clean theres not so much treble and the upper ranges of the volume have enough bleed. Now theres enough there, but if i use resistors to get the 4-5 range clean, the 6-8 area is too dark.
Anyways, it's not as bad as it sounds, i just wish i could get it perfect as on all my others because this guitar is really special to me. But i'll make do. Thanks for the replies.

[jojokeo]

With my others i can use resistors/pot in series so that when it gets down there to where it's clean theres not so much treble and the upper ranges of the volume have enough bleed. Now theres enough there, but if i use resistors to get the 4-5 range clean, the 6-8 area is too dark.

Without seeing a schematic it's hard to analyze if what you're trying to describe is the same as what I'm visioning? So I'll take a stab and guess you're putting a resistor across the vol pot to lower the pot's resistance? This will cause a double edged sword effect similar to what you're describing. Also, there is several ways to wire up a tone pot in a guitar and I bet the cap is too high of a value (but lets worry about this later). But, without going into further details - unsolder the tone cap and all resistors and/or caps on or around Volume pot. Now play and test guitar. How does guitar/neck pu sound and turning down the volume control range? Try your usual treble bleed if necessary - but still leave the tone cap unsoldered to ground. You don't want it influencing anything until you get the neck pu's sound the way you want first. If you're not happy, go up to 1Meg for the value of the neck's Vol pot. The higher the value the brighter and punchier your tone will be.

After all this, only then solder the cap back to ground and check out the difference it makes. I don't like the standard .1, .05, or even the .02 values normally used personally. I will go all the way down to .005 or even .002 on some guitars. I HATE a muffley-dark sound for everything. I just want to trim off only a slight amount of top end but that's it. Lastly, I turn my tone pots into "no load" types by filing away the trace on one side of the resistance track. Meaning all the way up on 10, the tone control is out of circuit. Turn it to 9 and below it "activates" and becomes in circuit allowing the cap to become the loading and high draining effect that it is. Modify the cap value to taste while still comparing the vol control's tone down through the ranges you're wanting.

You should find your happy zone following this systematic approach. Good luck & follow up with your results.

[burt_toast]

are you going straight into amp, or thru a treble-booster first (which, for me, greatly improves the whole guitar treble-bleed thing) ? hmm...

[super&plexi]

#1 to JOE & no load. and just a stab,....are P.U.s in  new guitar in question similar in respect to ohms/load,  henries?  they have a curve don't they?  I know from last month's tearing into my axes, tapers in pots vary all over the place, some react to my style of vol. swell, some don't. some read higher slightly backed off, than full. and funny, but was just talking to wife about differences in equip, but sounding the same, as in I've got 3 or 4 tube screamers, sonic distortion, OD1, handmade variants,....but I always sound like me. heck I'd love something that made me sound different. maybe you can learn to appreciate the difference.

[HotBluePlates]

Could it be that you just don't like this guitar's sound?

I've got a homebrew ash-body Tele, and 9 times out of 10 I'm playing it unplugged at home (cause my son is asleep). You might think Tele pickups are what give them "twang" but this guitar unplugged has a midrangy honk if you dig into the stings at all (a soft touch can give a smooth sound). It's something about the ash and the brass bridge.

Now even my Tele can sound muddy when using just the stock single-coil neck pickup, even with the tone full up. That said, if I added both a hollowing of the body and humbuckers that weren't on the bright end (or worse, were really hot ceramic HB's), I could imagine how I'd wind up with a sound that was mud unless so much treble was added that it sounded harsh.

So I wonder about the basic sound of the guitar, unplugged, and then how the pickup's personality layers on that. I also wonder if you changed from one pickup that wasn't right for you in this particular guitar, to a different pickup that wasn't right for you in this guitar (or maybe just in the neck position).