Hi folks,
I've got a hot rodded Kay with a HS Filtertron in the neck, and a Dynasonic in the Bridge, and with your help I've dialed in the tone caps to where I like them(.022 in neck, .033 in Bridge), but I dislike the treble rolloff when backing off the volume. I read an alternative wiring to the installation of a treble bleed pair on the pot. It involves running the wire from the vol. pot to the input lug of the tone cap, not the center lug. My tone caps(paper in oil) are mounted from the center lug to ground. Any and all suggestions will be gratefully appreciated. Thanks...Bob
You can try it, but the tone pot isn't the problem with the treble roll off, the volume control is. You can test this by removing the wire to the tone pot and you'll see you still lose some highs when you turn down the volume.
The alternate wiring makes the tone control have less effect as you turn down the volume control.
Other than running the signal through an active buffer, the treble bleed cap/resistor trick is the only thing I know of.
It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. — Albert Einstein
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Thank you, David. I knew the volume pot was where the bleed circuit would go. The alternate wiring I was told would make for "a more transparent" sound and more interactive. So, Could I have a suggestion for the component values? I've seen .001 with 110K, .001 with 220K, 500pf with 330K. What values make sense to you fellows? Do I use different values for the Filtertron and the DynaSonic?
The rolloff is far more noticeable on the Filtertron...Bob
I think what you are talking about is "50's wiring" where you connect the cap to the output lug of the volume pot rather than ground. There is a treble bleed circuit with a cap and resistor ( the values of which I can't remember off hand) that connects between the input lug and the output lug of the volume pot.
50's wiring make the tone and volume interactive as well so and adjustment of one alters the other slightly. Once you get used to that aspect it's great. You don't lose the highs as you roll off the volume.
The one thing I can't do is place the cap in between the volume and tone pots. That's the on aspect of 50's wiring I can't due because of the nature of the body cavity. So what I was told about was the connecting wire from the volume pot to the input of the tone pot. I'm still open to the bleed circuit, but I'm hoping to get value suggestions based on people's experience with them....Bob
I use .0012uf and 130k resistor in series with 250k volume pots and .001uf and 160k in series with 500k volume pots. Both work very well.
Yes, I totally agree with that.Originally Posted by Ward
(although I use different values)
Some will advise using a resistor/cap in parallel, but when you add that across pin2 and pin3 of the pot it alters the taper too much. Using the resistor/cap in series doesn't mess with the taper.
What values do you use, please?...Bob
It's not a recipie, your values will be different than mine.
Depending on the instrument, the pots, and the wind, one has to add treble bleed relevant to what things sound like after the pickups are installed ...then the part value choices get made.
You'll need to do your own experimentation with the pickups you use, and the instrument they are installed into.
Duncan shows the values of a .002µƒ cap and a 100K resistor. So there's another variation.
I agree with Brad that so sometimes need to tweak the values to match the guitar/pickups/pots etc.
It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. — Albert Einstein
www.sgd-lutherie.com
www.myspace.com/sgdlutherie
www.myspace.com/davidschwab
My treble bleed mod (we'll try to get it on the website at some point) is a little more intuitive in that I take the capacitor (whether you like it in parallel with a resistor or not) and connect it to the unused lug of the tone pot. It requires the tone pot to be wired with the hot in the center, and the capacitor between the outside lug and ground. This works for your situation, where you say that you can't use the capacitor as the bridge between the two pots, although you could easily extend the cap with a wire.
In this configuration, the treble bleed works as intended, but as you turn the tone control down, the treble bleed is progressively removed from the circuit. What I hate most about treble bleeds is that when I want to work the tone control AND the volume control, I'm left with a midrangey hybrid of treble cut and bass cut (which is really what the treble bleed mod is in the circuit) The treble bleed allows highs to pass while the rest of the signal is being lowered. That's tantamount to a low end roll off, unless you get the cap and resistor values exactly right.
Anyway I don't know if that helps you on your particular guitar, but when I heard the word "interactive" I thought of mine being interactive with the tone pot. If you happen to be playing with the volume at 75% for example, the tone pot still brings good value to the equation by simultaneously lessening the effect of the treble bleed as it attenuates the highs. There are some great sounds in those ranges.
As for cap values, I usually take the easy way out and just run a .0022 with no resistor. It's more dramatic in the early part of the taper without the resistor, but I figure I have the tone control there to save me if I want to find more balance.
250k pots are much less prone to treble loss (as they are turned down) than 500k pots.
So you'd rather use 500k pots as it has more top end when on full?
If you fit a no-load tone pot and a 250k vol pot, then the pick up is seeing the same load impedance (vol & tone on full) as if 500k vol and tone pots had been used.
For buckers I use the 50's wiring, turning the volume pot down doesn't kill the treble as much as modern wiring does. For a Les Paul remove any plastic coated wiring in there and use the vintage braid type stuff, that will help as well. I pretty much completely redo the wiring harness in any guitar I use for testing, it makes a nite and day difference compared to factory harnesses. The treble bleed thing is kind of a bandaid thing I think, never had a need for that.
http://www.SDpickups.com
Stephens Design Pickups
When you turn down the volume control, you introduce a series resistance that acts with any capacitance to ground located from the vol pot to the input of the amp, or pedal, to filter out highs. Most of that capacitance is from the guitar cable, not from the wiring from the pot to the switch and to the output jack. A cable might be 500pf. How can you get nearly 500pf inside the guitar? It does add up to more than a few inches, of course, and so there is some effect. But using low capacitance cable inside the guitar cannot get rid of the capacitance of the cable. In any case, that capacitance helps set the sound of the guitar by determining the resonant frequency.
I totally agree.
It's one of those things where the rubber-meets-the-road, it's where the EE types can't get it (mind over eardrums) but the musicians can (eardrums over mind).
Agree to that too.
I've noticed it's needed (treble bleed) much more by players who use solid state devices/amps and mostly by players who tend set up their live sound with the (guitar) volume knob at 10, then later turn it down and say "hey, where'd my sound go?".
Players that go straight into a tube amp, or set up their sound with the guitar volume under 8 have no need for the treble bleed as a rule.
I doubt that Maxwell's equations work any differently for musicians. Any body has an equal opportunity to deny reality, and we all do it from time to time.
Setting up with some treble loss dialed in is a good idea if you can get the sound you want that way.
The effect is certainly still there going straight into a tube amp. The effect was know before there were SS amps, right?
Well the subject has been "discussed" to death on other forums, so I won't bite here, it's sufficient to say try it and see for yourself if you can't hear the difference ...don't be disappointed, many can't.
(and many can't tune their guitars by ear either, relying on electronic tuners)
This is just like the old "Neve" console thing, shunting the 47uF electrolytics that couple segments with .1uF poly's. EE's can't rationalize it with the math so they deny it's audible effect.
Hear the change in tone from turning down the volume control? Of course I can hear that, both on tube and SS amps. Is the effect exactly the same? Of course not, the amps do not sound the same.
But it is still true that if the cable causes a loss of highs when the volume is turned down, using lower capacitance wiring in the guitar cannot get rid of that effect. If you want to support Possum and claim that it does, I have no problem with that. But that does not make it true.
Anyway, we're talking about treble bleed, cable losses are another thread.
Anyway, we're talking about treble bleed, cable losses are another thread.
OK, but it is the cable capacitance that causes most of the loss of highs, when the volume is turned down, that the treble bleed is designed to counteract.
Ok, but even with a 2-inch (0uF) cable it's the treble bleed that we're talking about, never mind the cable capacitance.
You definitely need to take care with your wiring harness as too much capacitance there will kill your pickups. Take your average offshore guitar. Make your best set of pickups and put them in. Now rewire the whole guitar with vintage braid wire with no plastic coated thin wire, put good pots and replace the junk tone caps with better ones. Keep the wiring only as long as needed, don't use quick connectors like Epiphones etc. do now. So, basically you got rid of alot of stuff thats capacitance heavy, now your pickups will sound more open and airy with more treble. To me, the wiring harness is a musical part by itself. Of course guitar cables are important, very very important, cheap long cords just kill treble. Many players in trying to emulate classic rock tones of the past completely forget the cables of that era were pretty bad, especially the long coil cords. These worked real well though with really bright strat pickups, like Hendrix. I basically NEVER test pickups in a stock factory harness and always urge my customers to first upgrade their wiring harness before they buy anything from me, especially if they are playing buckers or P90s. Strats and teles seem to suffer less from this than darker pickup guitars.
http://www.SDpickups.com
Stephens Design Pickups
Ok, but even with a 2-inch (0uF) cable it's the treble bleed that we're talking about, never mind the cable capacitance.
I am not sure how to explain this better, but will try again. The series resistance of the vol pot and the capacitance of the cable (and some of the cabling inside the guitar) produce the effect that you are trying to counteract with the treble cap. Without the cable, there is not much of an effect to counteract.
Just so we're all singing from the same songsheet here... What exactly is the difference between the two wiring hookups under discussion?
Is there any electrical difference to the schematic, or are we talking about the difference between cloth covered retro wires and coax?
The only difference I can see between "50s" and "Modern" wiring on a Les Paul is that the lugs on the tone pot are swapped. But because the tone pot is wired as a variable resistor with the third lug unused, swapping them makes no electrical difference.
Or maybe we're all thinking of different schematics when we say "50s" and "Modern". For instance there's the one where the volume controls are wired "backwards" with the pickup connected to the wiper. That may well make the tone control behave differently.
Whatever, if you make the treble bleed cap too big, it can make the guitar sound thin and trashy when the volume is backed off. It only compensates the cable capacitance correctly at one volume setting.
"Enzo, I see that you replied parasitic oscillations. Is that a hypothesis? Or is that your amazing metal band I should check out?"
That really only applies to the "offshore" guitars, most decent guitars have decent wire these days and don't really need a new harness installed, but it's nice work ($) if you can get it.
(older Japaneese as well, Teisco etc)
I'd also disagree to using the "vintage braid" wire, although I certainly understand that comming from a guy that likes the world to be into PAF's.
I prefer a decent 2 conductor with shield so the pickups can be phase adjusted in the control cavity. I'm currently using some decent Canare two conductor, which is like 3-5pF/Ft.
Since most guitars only use between 16-20" of wire to connect the pickups to the pot/switch in the control cavity, I feel one can well afford 6-10pF any hf roll-off is well above the range of the response of the pickup.
No need to explain Mike, it actually works without you.
This is so reproducable, even a cave man can do it.
(appologys to the Neandrethalls amoung us)
With the treble bleed in place connect a 20 foot cable, note the effect, then connect 1 foot cable, you will note the same tonal effect, which really puts a cramp in your point but again it's one of those rubber-meets-the-road things. That's the beauitiful thing about actually doing listening tests, and using the ears instead of the mind when it comes to sound and music related issues, one can tell if something works without needing any others explainations.
The 50's wiring uses the tone-pot connection on the wiper (pin-2) of the volume pot, the modern wiring uses it at the pin-3 (CW) location.
Now EE's will often dismiss this wiring scheme as not having any relavant effect, but if you try it, you'll (should) hear the difference, specially when using the guitar when the volume pot is down from full.
(if you can't don't worry, some people can't)
Is that the only difference, or does the modern wiring also have the volume controls backwards, feeding the pickup signals to the wipers and taking the output to the jack from the CW terminals?
Either way it's a different circuit, so it could sound different. Wire it one way, and when the volume is down, some of the volume pot's track resistance ends up in series with the tone circuit. Wire it the other way, and that doesn't happen because the tone network is hooked straight across the pickup.
Shielded cable vs. 50s cloth covered is a different issue :-)
"Enzo, I see that you replied parasitic oscillations. Is that a hypothesis? Or is that your amazing metal band I should check out?"
Wishful thinking! Seriously though, if the pickup is connected to the outside lug, and the amp end goes to the wiper, and the tone is connected to the same lug as the pickup, you have a constant interaction between pickup and tone.
If the tone is to the wiper, then as you turn down the volume, you are placing resistance between the pickup and tone control, but you have the tone circuit on the amp end. That probably changes the way the control works, but I don't see where it would stop treble loss, since you are still putting a series resistance after the pickup while also reducing the resistance between the pickup and ground.
I doubt you'll hear any difference there. I hate that cloth covered crap....or are we talking about the difference between cloth covered retro wires and coax?
A lot of two pickup basses are wired up that way, and I find you get a little more treble loss when turning down. Same is true if you use something like a 1Meg pot. They are brighter when on 10, but sound duller when turning them down. Same is true of 500K vs. 250K, but to a smaller extent.Or maybe we're all thinking of different schematics when we say "50s" and "Modern". For instance there's the one where the volume controls are wired "backwards" with the pickup connected to the wiper. That may well make the tone control behave differently.
That's why you need the resistor there. That mixes some low end back in.Whatever, if you make the treble bleed cap too big, it can make the guitar sound thin and trashy at low volume.
The only guitar I have a treble bleed circuit in is my Tele-Paul. And that was just so I could get that trashy thin tone when the control is almost all the way off. Sometimes a thin sounding guitar fits into the mix better. Often times guitarist use too much low end and that doesn't leave room for the bass and drums. I'm always turning down the bass knobs on the guitarists' amps I play with when they aren't looking!
It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. — Albert Einstein
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www.myspace.com/davidschwab
Say you have two capacitors in parallel, and one of them is larger than the other. If you want to reduce the total capacitance, it makes more sense to change the one that is larger since it has more effect on the total for the same percentage change. In the case of your guitar, a normal cable to the amp has more capacitance than the wiring harness from the vol pot to the jack. It is also a lot easier to change the cable than to rewire the harness. I do not see much point in redoing the harness.
In any case you need a certain amount of capacitance to get the right sound. There is nothing wrong with the harness providing part of that.
In another discussion, I believe you were trying to find a way to increase the capacitance of the pickup. It seems easier just to leave it in the harness!
Given that you changed almost everything, how can you know that the improvement is due to the wiring versus the pots versus whatever?
Well, maybe some audio EEs never heard of this effect and trick and math, but it is well known to the RF community, and all the capacitor manufacturers have application notes explaining the issue. Sells more capacitors.
No cramp on my point. Of course the treble bleed circuit has an effect when you use either a 1 foot or a twenty foot cable. It bypasses highs around part of the vol pot resistance in either case. The point is that you do not need to counteract the high frequency loss from turning the volume part way down unless you have enough capacitance to cause the loss. A one foot cable does not have very much. A twenty foot cable has enough.
With the treble bleed in place connect a 20 foot cable, note the effect, then connect 1 foot cable, you will note the same tonal effect, which really puts a cramp in your point but again it's one of those rubber-meets-the-road things. That's the beauitiful thing about actually doing listening tests, and using the ears instead of the mind when it comes to sound and music related issues, one can tell if something works without needing any others explainations.
Proof of this is shown by placing a JFET buffer after your controls, but before the cable, such as in the typical Stratoblaster install. You now have no treble loss when turning down the controls, since the pickups and controls are isolated from the cable.
It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. — Albert Einstein
www.sgd-lutherie.com
www.myspace.com/sgdlutherie
www.myspace.com/davidschwab
Yes, and vintage weenies will tell you that this sounds terrible! :-/
"Enzo, I see that you replied parasitic oscillations. Is that a hypothesis? Or is that your amazing metal band I should check out?"
I might too, unless there is enough capacitance located at the input to the buffer to set the resonance at about the same frequency as my favorite cable does. Isolating the guitar from the cable capacitance is great because cables differ and cause change in response when using the volume control. But you still have to get it right to start with! Some people forget this.
David, thanks for pointing out the effect of a buffer.
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