G&L Tribute Legacy Alnico Pups -- WAAAAAY too Trebly

[bob p]

I recently picked up a G&L Tribute Legacy when one of the big box stores had a one-day sale. I really like the guitar. Playability, fit and finsh are much better than the MexiFenders, though I'm having trouble getting used to the PTB tone circuit.

The "PTB" tone circuit is G&L's implementation of a passive treble and bass control circuit. The idea is that instead of wiring a strat with 2 tone controls they wire it up wtih a master treble cut and a master bass cut. I've attached the schematic.

Legacy_schematic_blockdiagram.pdf

I'm having trouble with the PTB circuit. It's way too bright. I find myself dialing the bass control from 7-10 to get a reasonable amount of un-cut bass, and cutting way back on the treble control. In comparison to a strat, where I can live with high amounts of treble on the dial, with the PTB circuit I find that I can't stand the sound of the guitar in the unless I dial the treble control down to about 2. I'm not kidding. 2. Even on the rhythm pickups. If I dial up the treble up any farther the tone ends up being a bunch of clanky high-frequency hash that totally lacks any body. It drives me crazy. It's like daggers in my ears.

At this point I'm not sure if the source of the problem is the pot / cap values chosen for the PTB circuit or the G&L designed Alnico V pickups on the Limited Edition GC models are just wound in a way that's so different from a strat that I just can't stomach them. Before I start an adventure that involves parts swapping in the tone circuit that may end up in pickup replacement I thought I'd ask if anyone has already been down this road.

For reference: I really like the sound of Texas Specials in the stock strat circuit.

[rjb]

I don't own any G&L guitars, but have wired several guitars with separate bass & treble cut controls.
Not exactly the same topology as yours- but close.
Here are some suggestions:

1) To warm icepick pickups, try a ~1nF "defroster" cap across the treble control.
See C3 in G&L's S-500 schematic:
http://www.glguitars.com/schematics/...ockdiagram.pdf

2) Unless you have an actual reason to cut the bass (e.g. muddy neck pickup, farty overdrive, jazz box feeding back), leave the bass cut control on 10 (i.e. shunting the bass-block cap).

-rb

[mozz]

Have you tried to adjust the pickups?

[rjb]

It has been speculated that Leo's high frequency hearing loss over time resulted in brighter & brighter products....
http://music-electronics-forum.com/t30921/#post279679

-rb

[Mick Bailey]

The tone circuit works really well and I've used it a few times. Sometimes I go with a 250k treble pot and 0.047uf cap for customers who like to use the treble knob as a wah. It also warms up the sound a little. I also have customers who prefer the sound without the 200pf treble/volume bypass cap. Make sure the bass control pot is working as it should - when zeroed you should get no bass cut.

Edit: With some very toppy guitars I end up raising the bass-side of the pickups towards the strings and the treble side away, and getting the pickups much closer to the strings than a regular setup. Not so close that you get string-suck or wolf-tones, though. My G&L equipped Tele is like this and sounds pretty evenly balanced.

[rjb]

Probably unnecessary clarification

I also have customers who prefer the sound without the 200pf treble/volume bypass cap.

According to the wiring diagrams, the S-500 has a 200pf treble bypass cap and a 1000pf cap that is always in parallel with the pickups; the Legacy has neither.

Make sure the bass control pot is working as it should - when zeroed you should get no bass cut.

As shown in the diagrams, the 2.2nf series capacitor is shunted by the anti-log 1M pot when turned full clockwise.
(I've used linear pots, so can wire it whichever way feels "natural" - although the C taper must have some advantage.)

- rb

[Mick Bailey]

Ah, yes - by zeroed I meant in this case fully clockwise. I was still thinking in the wrong mode for this - I've just installed two bass controls (one for each pickup) using regular A1M pots in a Jazzmaster rhythm circuit and zero is full bass. Seems to be more intuitive with those edge-mounted controls than rotating the correct way. Works exceptionally well alongside a master volume and regular master treble control.

[bob p]

thanks everyone for posting.

Regarding the suggestion about pickup adjustment --

the G&L Tribute (import) series is supposed to have the setup performed by the USA factory, though I can't believe that it ever happened with my guitar.

When I received the guitar the bass side of the pickups were cranked way up and the treble side of the pickups were cranked way down. The slope on the pickup covers was like nothing I had ever seen. Out of the box the guitar had a horrible mismatch in volume between the strings. Just horrible. The wound strings were LOUD and the unwound strings were far too quiet. Just looking at the guitar was enough to make me think that the setup was a half-assed job performed by someone who didn't know what he was doing, or perhaps someone who was just assembling their portion of the guitar on the assembly line and shoving it off to the next station as fast as they could. There's just no way that anyone listened to this guitar and performed a pickup adjustment. No way.

I started off using a standard "Strat" setup. That evened out the volume on the strings, but it also ended up revealing how harsh and icepicky this guitar sounded. With the pickups "reasonably" close to the strings for a strat the pickups produced huge magnetic effects, so I had to back them down. Way down. I think the output of these pickups has to be pretty high for Alnico V pickups, as I had to dial them down a lot farther than I typically locate Alnico strat pickups like my Texas Specials.

The best overall balance of tone came with the bass and treble sides of the pickups fairly even, but with the pickups down pretty far from the strings. I had to set the bass side pretty low to avoid magnetic effects on the strings, then I balanced the treble side for volume. The end result is that the pickups ended up being fairly even in height between the wound and unwound sides.

Lowering the pickups helped to tame the offensive clankiness, but I still can't tolerate a tone control setting above 5.

[bob p]

> Ah, yes - by zeroed I meant in this case fully clockwise.

I understood this as what you meant.


> With some very toppy guitars I end up raising the bass-side of the pickups
> towards the strings and the treble side away, and getting the pickups much
> closer to the strings than a regular setup. Not so close that you get string-suck
> or wolf-tones, though. My G&L equipped Tele is like this and sounds pretty
> evenly balanced.

I have a Tribute ASAT and that guitar came from the factory with good pickup adjustment, good tonal balance and a good range of control in the stock tone circuit. that's not the case with my Legacy Tribute though. And I'm not sure whether it's due to different pickups or to the different tone circuit, as both things change in moving from one guitar to the other.

With this Tribute Legacy I couldn't raise the bass side of the pickups very far because the magnetic pulsing effect was larger than I expected it to be. I ended up having to leave them a lot lower than the typical "Strat" setup to prevent interaction between the strings/magnets. What struck me as odd was that to balance the tone, with the pickups sufficiently low, the pickups ended up having almost no slope from the bass to the treble side.

With the pickups adjusted in this way the guitar is still WAAAAY too bright. I'm reminded of those times that I've heard people play strats that had wayy too much treble in the signal, where their playing sounded like a lot of high frequency hash and clanky fret noise. (I'm guessing those people have HF hearing loss.)

G&L's marketing says that the Legacy is different sounding than a strat. They claim that the Legacy and the PTB circuit much better "clarity" and "cutting through the mix". What I'm hearing isn't clarity -- it's excessive HF content that I wish wasn't there. Maybe David is right -- that Leo and his team just kept dialing in more and more treble as his hearing suffered more and more HF loss.

[bob p]

changes to the PTB Circuit --

At this point I don't have a good handle on whether the excessive HF content is coming from the pickups or from the PTB circuit. I notice that the PTB uses a 500k pot in the treble bleed circuit rather than a typical strat value of 250k, which should account for some of the added treble in the signal.

As far as usability of the control is concerned, the sound is only usable to me in a very narrow range -- between 2-4. Below 3 the tone rapidly falls off and becomes very dark and muddy, and above 5 it feels like someone is stabbing me in the face with burning sparklers. Even at only moderate volumes the shrillness hurts my ears. Optimally I'd like to expand the range of 2-5 on the pot so that this range is spread from 1-10 on the control.

I'm guessing that the circuit might become more tolerable if I just switched over to a 250k pot, as this might move the circuit into the range that I've found useful on the 500k pot. I've thought about just tacking a 500k resistor across lugs 1 and 3 to see what happens, but I thought I'd ask for other peoples' experience as to whether any of these proposed changes might work better than the others:

1. changing the value of the cap that's in series with the tone pot to shift the filter frequency
2. adding a small cap in parallel with the pickups to shunt some HF to ground
3. changing the tone pot to a smaller value, like 250kA or 330kA.

I know how to calculate the RC filter frequency, but the inductance of the pickups throws a wrench into the works for me -- I'm not quite sure how the pickup inductance is going to play into parts selection, so there may be some trial and error that's unavoidable. Until I can get inside to take measurements off of the tone pot, I'm not sure what resistances will correspond to the range that I like on the pot (2-5) because it has an audio taper.

Suggestions?

[mozz]

Maybe the "q" factor is high causing the peak to be in the fingers nails on chalk board freq. I would try the 500k tacked across the pot and see if that tames things.

[rjb]

G&L's marketing says that the Legacy is different sounding than a strat. They claim that the Legacy and the PTB circuit much better "clarity" and "cutting through the mix". What I'm hearing isn't clarity -- it's excessive HF content that I wish wasn't there....

Maybe they're referring to what sax players call "edge".
Sax on the Web > The Saxophone Tone and Edge

A bright tone is sometimes described as having edge. This edge, or brilliance of tone, helps the tone project....

I had an interesting discussion recently with saxophonist Santy Runyon.... He related a story from his days in the Chicago Theater. A cello player behind him was sawing away, making all kinds of racket. Santy asked the cellist if he realized how edgy the tone was, the cello sounded like a buzz saw. The man replied, "I have to play this way, otherwise, they can't hear me past the third row. It doesn't sound the same out there." And he was 100% correct!

At this point I don't have a good handle on whether the excessive HF content is coming from the pickups or from the PTB circuit.

Why does it have to be one or the other? It's a system, man.
Although it may turn out that you just can't live with those pickups, it'd be a lot easier and cheaper to swap some components than to rewind or replace the pups.

I notice that the PTB uses a 500k pot in the treble bleed circuit rather than a typical strat value of 250k,...

I know how to calculate the RC filter frequency, but the inductance of the pickups throws a wrench into the works for me -- ... so there may be some trial and error that's unavoidable....

Suggestions?

My suggestion is to jump in and start trying different component values. Don't overthink it. You can assume the G&L pickups have lower inductance and higher resonant frequency than Texas Specials, but why calculate RC filter frequencies? Do you know the resonant frequencies of a standard Strat with Texas Specials, using your favorite cable, for every pickup combination and tone setting? I bet not. Just "tune" it by ear.

I recently went through a similar exercise with an overly-complicated Telecaster harness (14 non-redundant, 20 possible switch combinations... self-inflicted wound). The first thing is to figure out a way to (fairly) quickly change components while still being able to play the guitar and adjust the controls. Different folks have their favorite methods, but here's what I did:

Get a set of jumpers like these (pulled apart into individual wires)
Premium Jumper Wires Male / Male 300mm Pack of 40
and a mini solderless breadboard
170 Point Solder-less Plug-in Breadboard White for Arduino Proto Shield.
Gather a 470kohm resistor and a set of E12 value caps in the range of, say, 1nF-22nF.
Open up the guitar, remove the stock caps, and solder-tack a jumper in place of each cap lead (color code and group the jumpers so you know what goes where). Replace the pickguard with the leads hanging out to reach the solderless breadboard, which you attach to the guitar face with painter's tape. Insert the leads into the breadboard, so you can try different cap values or shunt the tone pot with the 470K resistor.

This is more or less the order I would go about it. Component refs are from the S-500 diagram.

1) Pick C3 "de-icepick" cap" value:
(Temporarily) tie treble pot lugs 2/3 to ground.
Turn all controls to 10 (Volume & Treble max; Bass zeroed).
Starting with 1nF, try caps for C3 until the resonant frequency drops from "aaargh" to "the brightest tone I want to hear from this guitar".
Also try the 470K resistor across the treble pot. If that helps, you'll probably want to change to a 250K treble pot, but not till after step 2.

2) Pick C4 Treble control value:
Turn Treble pot down to zero, and try different caps between lugs 2/3 and ground.
Since you found 22nF to be "dark and muddy", try smaller values until you find a "rolled off" frequency you like.

If you're pretty sure you want a 250K Treble pot, maybe remove the pickguard again and install it now, along with C3 and C4. Replace pg; check that you like the treble tone range and taper.

3) Decide you don't need no stinkin' Volume treble-bleed cap (C2):
The cap's purpose is to retain highs as you turn down volume. If you have too many highs to begin with, losing highs by rolling off the volume could be a good thing.
Anyways, higher cap value = greater effect (ex. vintage 1000pF Tele bypass accentuates highs as volume is lowered).
So C2 = 200pF is probably reasonable; play with it if you feel like it. Or not.

4) Pick C1 Bass block value:
Turn Bass control to zero. C1 stock value = 2.2nF; lower values block more bass; higher values pass more bass.
The effect can be pretty subtle with clean tones, but quite useful (I'm told) in cleaning up fuzz/distortion. "Ideal" value depends on what you intend to use it for.

-rb

[Mick Bailey]

The stock bass control works wonders with fuzz. I demo'd the last guitar I did through a Fuzzrite as well as a diode-clipper distortion. What's interesting with the Fuzzrite is the volume increase with rolling off the bass. It not only removes the flabby intermodulation but significantly boosts the volume. I was easily able to A-B the bass controls with the Jazzmaster because I used the rhythm circuit switch as a dual bypass for the bass controls. Night and day. Really nice on clean, too.

As yet I don't have an explanation why this would be the case. Maybe the LF produces some type of blocking distortion in the fuzz.

The setup with this guitar is 2x Curtis Novak wide-range humbuckers, though. Perhaps the same setup with single-coils may not work the same. I didn't have my Fuzzrite when I last wired a S/C guitar with the bass control.

I think bass-cut is overlooked. It even works well with (strangely) bass guitars. I recently rewired a Gibson EB2 that has a factory bass cut which they call a 'baritone' circuit. This works much better than you'd think. A bass with no bass. But you rarely hear a bass with no fundamentals on the lower notes and in a world searching for new sounds it makes a bit of a left-turn.

[bob p]

thanks. I haven't been looking forward to digging into this because of the inconvenience involved in disassembling the guitar, making changes, reassembling, and repeating the cycle all over again.

I like your idea to run all of the leads out to a breadboard attached to the outside of the guitar. I have all the parts necessary to do that, but for some reason I didn't think of doing that. Did you have any problems with unshielding / noise?

Maybe my aversion to strapping a breadboard to the outside of the guitar is based on how much I laughed at Devo when they first came along in the late 70s. I remember rolling on the floor when I saw this unknown act perform "Satisfaction" on Saturday Night Live in 1978:

^^^Note the lead guitarist's axe, with all of his effects strapped onto the body with loose wires and tape. We all laughed our asses off when we saw that.

I guess that's what people had to do back in the day before rackmounted guitar processors.




And some of his interior wiring on another guitar:



It was funny that SNL had Devo performing their version of "Satisfaction" a week after SNL hosted The Rolling Stones.

[rjb]

thanks. I haven't been looking forward to digging into this because of the inconvenience involved in disassembling the guitar, making changes, reassembling, and repeating the cycle all over again.

Its a little easier with a Tele - separate pickguard and control plate. (Although I wound up removing the pg three times anyway - first, to install the pickups; second to convert the neck HB to 4-wire; third to ground the screws and slugs.)

I like your idea to run all of the leads out to a breadboard attached to the outside of the guitar. I have all the parts necessary to do that, but for some reason I didn't think of doing that. Did you have any problems with unshielding / noise?

The breadboard idea was a variation on the common practice of tacking alligator leads to the pots. I'm sure its been done before, but I haven't seen it elsewhere. Another "brilliant innovation" was that I happened to have a 12 position rotary cap selector switch on hand (an "inductorless Varitone" that never got installed).

Yea, the setup was kinda noisy/hummy - but not so bad after I backed away from the amp and turned off the Ott light. Twisting wire pairs might have helped(?) It was good enough to hear tone differences, and that the neck pickup was noisier than the bridge.

Maybe my aversion to strapping a breadboard to the outside of the guitar is based on how much I laughed at Devo when they first came along in the late 70s.

No problem for me. I'm too socially retarded to care about looking silly.

-rb