Modifications to improve the tone of your Archtop

[AlanC]

Any suggestions to improve the tone of an archtop? I had a switch failure in my Tal Farlow but since having the switch and a tone pot replaced the tone is now very thin and overrly bright. I gig with this guitar so it does matter.

 

I had already installed an ebony bridge and more recently installed an ebony base to the bridge but since the switch/tone pot replacement the tone now is very ordinary. In the last couple of days I put different capacitors in and whilst its better its still not what it was.

 

It was great. Suggestions would be very much appreciated.

[jc1funk]

Apologies if this stating/asking the obvious, but what were the replacements? Exact same model/spec or something else?

 

Also, did whoever changed the pot & switch have any impact on the pickup height?

[AlanC]

Apologies if this stating/asking the obvious, but what were the replacements? Exact same model/spec or something else?

 

Also, did whoever changed the pot & switch have any impact on the pickup height?

 

Thanks for your comments. Appreciated. Actually I assumed that they were the same parts used to replace but I probably should ask. Pick up height was unaffected.

 

I want a more mellow less trebly sound. Maybe the ebony bridge base doesnt work on a Tal. I may try the rosewood again.

[Anthony Buckeridge]

Alan.

 

Obviously, without hearing the Instrument or seeing the Components one is forced to purely make a hunch.

 

My hunch would be that whereas Older Gibson Instruments were fitted with Potentiometers rated at 500 Ohms, for a great many years now, far lower Impedances like 300 or 250 Ohms have become the norm fitted to the most commonly experienced Gibson Electric Models especially the Solid Body Models.

 

So these values to an individual with limited experience might seem to be completely correct. A Tal Farlow Archtop might well be a Guitar that whoever worked upon your Instrument is un-familiar with, does not have the Correct Impedance Parts for, and thus fitted the Parts they had to hand which would get it working, which they would normally use for Modern Solid Body Gibson's, so to their mind, a reasonable thing to do.

 

However, these Lower Impedance Parts, may have and may give a far Different Tonal Value than the Older Higher Value Parts would typically give. Like Fender Guitars with Single Coil Pickups which also use 250 Impedance Potentiometers, it is not simply the Pickups that create the Bright Fender Sound but also the Potentiometer Values. A Further Hunch is that the Repairman might also have used Far Cheaper, Commonly Available Chinese Replacement Parts, which also Sound Thinner than the Standard American Counterparts.

 

To Complicate things further. Older Potentiometers were typically Audio Taper whereas many New Potentiometers used on Modern Guitars are Linear Taper. Your Ear reacts differently to them when you adjust the different Potentiometers, so they Sound Different. Lastly The Capacitors used also affect the Sound. Values typically used today have changed wildly from what were used many years ago when the Tal Farlow Model was first launched. Also different Brands of Parts definitely do give a different Quality to the Sound. Personally I favour CTS, Audio Taper Pots and Switchcraft Switches and Jack Sockets. Some Wiring Designs feature Audio Taper Pots and Linear Taper Pots for different control functions, often with an extra component.

 

Below is a Pdf will which will enable you to Decipher Codes on the back of CTS Pots.

 

http://www.ctscorp.com/components/Datasheets/450g.pdf

 

 

 

Really good Luthiers and Players will have different experiences, different knowledge of, and subsequently different ideas of what constitutes the best solution in Wiring Guitars, and can argue about these things.

 

The Bottom line to all this that when the Repairman Fixed your Guitar he should have given you All the Old Parts he Replaced, to Demonstrate that he Actually Replaced Them. This is Standard Operating Procedure for any High Quality Luthier.

 

So you should have the Old Parts and can Check the Values so see if they Match the Parts that have been Replaced. If not, try to get them from the Repairman double quick time before he throws them away, or check them against any Remaining Values left in the Guitar, or Contact Gibson with your Serial Number and ask Definitively what the Values should be. Possibly someone on a Fora with a Tal Farlow, might be able to tell you.

 

The way to fix this is to get at Least as Good Components Fitted to your Guitar as were in them Originally, (CTS may be Superior) but they MUST be to the Same Values as Original, and be the Same Types (Audio or Linear Taper) with the Same Value Capacitors and Types if they are to Sound the Same in the way you Desire. Do NOT purchase parts from a Cut Price Source or Supplier, they may well be Seconds or the Values Differ Wildly from what you want, though they seem just the Same.

 

http://www.guitarpartsresource.com/electrical_ctspots.htm

 

 

 

I would be looking for an Older Luthier, experienced with Archtops.

 

And what you could do is to post your problem over on Frets. Net http://fretsnet.ning.com/

 

Calling for an Australian Luthier in the Title. I know that there are definitely a number of Excellent Australian Luthiers that go on that Site who are very experienced, and I would take your Guitar to one of them if you have a job to find anybody Locally who you have Complete Confidence in. The Experience of the Luthier is the Key to getting a Good Job done.

 

Getting a Great Luthier is half the Battle, remember to stress the fact that you don't simply want the Guitar to work. Your previous Luthier did a good job in that respect, so no criticism is implied towards him. You need the Guitar to Perform with the Typical Warm Sound as it would with all the Original Parts you were used to. By the way, this is in part WHY Gibson Manufacture Original Specification VOS Models. A Player purchasing a Modern Guitar of the same Model will find it behaves differently because of the Modern Component Values.

 

Good Luck!

[AlanC]

Alan.

 

Obviously, without hearing the Instrument or seeing the Components one is forced to purely make a hunch.

 

My hunch would be that whereas Older Gibson Instruments were fitted with Potentiometers rated at 500 Ohms, for a great many years now, far lower Impedances like 300 or 250 Ohms have become the norm fitted to the most commonly experienced Gibson Electric Models especially the Solid Body Models.

 

So these values to an individual with limited experience might seem to be completely correct. A Tal Farlow Archtop might well be a Guitar that whoever worked upon your Instrument is un-familiar with, does not have the Correct Impedance Parts for, and thus fitted the Parts they had to hand which would get it working, which they would normally use for Modern Solid Body Gibson's, so to their mind, a reasonable thing to do.

 

However, these Lower Impedance Parts, may have and may give a far Different Tonal Value than the Older Higher Value Parts would typically give. Like Fender Guitars with Single Coil Pickups which also use 250 Impedance Potentiometers, it is not simply the Pickups that create the Bright Fender Sound but also the Potentiometer Values. A Further Hunch is that the Repairman might also have used Far Cheaper, Commonly Available Chinese Replacement Parts, which also Sound Thinner than the Standard American Counterparts.

 

To Complicate things further. Older Potentiometers were typically Audio Taper whereas many New Potentiometers used on Modern Guitars are Linear Taper. Your Ear reacts differently to them when you adjust the different Potentiometers, so they Sound Different. Lastly The Capacitors used also affect the Sound. Values typically used today have changed wildly from what were used many years ago when the Tal Farlow Model was first launched. Also different Brands of Parts definitely do give a different Quality to the Sound. Personally I favour CTS, Audio Taper Pots and Switchcraft Switches and Jack Sockets. Some Wiring Designs feature Audio Taper Pots and Linear Taper Pots for different control functions, often with an extra component.

 

Below is a Pdf will which will enable you to Decipher Codes on the back of CTS Pots.

 

http://www.ctscorp.c...sheets/450g.pdf

 

 

 

Really good Luthiers and Players will have different experiences, different knowledge of, and subsequently different ideas of what constitutes the best solution in Wiring Guitars, and can argue about these things.

 

The Bottom line to all this that when the Repairman Fixed your Guitar he should have given you All the Old Parts he Replaced, to Demonstrate that he Actually Replaced Them. This is Standard Operating Procedure for any High Quality Luthier.

 

So you should have the Old Parts and can Check the Values so see if they Match the Parts that have been Replaced. If not, try to get them from the Repairman double quick time before he throws them away, or check them against any Remaining Values left in the Guitar, or Contact Gibson with your Serial Number and ask Definitively what the Values should be. Possibly someone on a Fora with a Tal Farlow, might be able to tell you.

 

The way to fix this is to get at Least as Good Components Fitted to your Guitar as were in them Originally, (CTS may be Superior) but they MUST be to the Same Values as Original, and be the Same Types (Audio or Linear Taper) with the Same Value Capacitors and Types if they are to Sound the Same in the way you Desire. Do NOT purchase parts from a Cut Price Source or Supplier, they may well be Seconds or the Values Differ Wildly from what you want, though they seem just the Same.

 

http://www.guitarpar...cal_ctspots.htm

 

 

 

I would be looking for an Older Luthier, experienced with Archtops.

 

And what you could do is to post your problem over on Frets. Net http://fretsnet.ning.com/

 

Calling for an Australian Luthier in the Title. I know that there are definitely a number of Excellent Australian Luthiers that go on that Site who are very experienced, and I would take your Guitar to one of them if you have a job to find anybody Locally who you have Complete Confidence in. The Experience of the Luthier is the Key to getting a Good Job done.

 

Getting a Great Luthier is half the Battle, remember to stress the fact that you don't simply want the Guitar to work. Your previous Luthier did a good job in that respect, so no criticism is implied towards him. You need the Guitar to Perform with the Typical Warm Sound as it would with all the Original Parts you were used to. By the way, this is in part WHY Gibson Manufacture Original Specification VOS Models. A Player purchasing a Modern Guitar of the same Model will find it behaves differently because of the Modern Component Values.

 

Good Luck!

 

Hi Anthony. Thank you for a really great reply. It has been very helpful.

 

The luthier I used is very experienced and in my view very good. And he's prepared to work with me to get it right. I'm pretty sure that he matched the Potentiometers. However when I complained about the tone, the first thing he checked was the Ohms cos apparently my old one was 500 Ohms and I could see that he thought that he might have made a mistake. But he assured me he hadn't. He did mention that the replacement pot would very likely have a different roll off which I assumed meant that the tone control worked differently and when I try and blend the 2 pickups which I do when I play rhythm the sound is not the same. But he may not have used Gibson parts so I'll ask him about the quality of the replacement parts.

 

I have a few archtops and I've replaced the metal bridges with ebony bridges in most cases. Reason being is for me the sound seems more distinctive, not as muddy when I chord and the tone of the first string is warmer and more musical if that makes sense. But the sound is more woody. In this case I'm thinking the sound might have become too woody and is now a little harsh and thin. In this case I replaced not only the bridge but also the bridge base from rosewood to ebony. The pickup failed pretty much straight after I replaced the bridge base so I didnt really get a chance to familiarise myself with the new sound. And also I'm not convinced that the bridge pickup is 100% right as it was intermittant when the fault emerged.

 

So I'm still on the journey but your response has been most detailed and very helpful. Thank you for taking the time to help.

[Danny W.]

Kilohms, people, not ohms.

 

Danny W.

[Anthony Buckeridge]

Quote: "The pickup failed pretty much straight after I replaced the bridge base so I didnt really get a chance to familiarise myself with the new sound. And also I'm not convinced that the bridge pickup is 100% right as it was intermittant when the fault emerged."

 

 

 

Alan. We only have the information you impart to go on. Thank you for the Additional Facts.

 

I think it's worth investigating the Brand Quality and Exact Specification of the Replaced Components as they make a difference.

 

However, if you have a Pickup that is working intermittently, something is broken, obviously at times making some kind of contact and clearly, sometimes not.

 

It's easily possible that a Circuitry Failing within the Faulty Pickup might be the cause of the Complete Internal Wiring of the Humbucker not providing the Full Specified Output of the Design.

 

Under such circumstances, it would be entirely unsurprising if there was a Significant Thinning of the Tonal Quality the Pickup Provides. For many years, certain types of Guitarist have sought Over-wound High Output Pickups which give a Full Fat Tone.

 

Session Players and Older Top Guitarists often have Vintage Instruments at their disposal which feature Lower Pickup Windings with a concomitant Lower Output, and a Strikingly Clear, Bright Tone. For instance, we know that with a Coil Tap Switch changing a Humbucker to a Single Coil we get a Brighter, Clearer Tone. Even Bass Pickups do this.

 

These are simply analogies to make the point that if for any reason a Certain Part of one of the Pickups, is not Working as it should, providing the Full, Specified Circuit, working as they were Designed to. That in itself might provide the Thinness of Tone that is bothering you, and whatever is done to the Pots, they can't fix that problem inherent to the Pickup.

 

To be entirely Honest, and I write this with the greatest possible respect. If One Pickup has needed to be replaced with "something", and another one is Faulty, and certain of the Potentiometers Fitted to the Instrument have needed to be Replaced. If this is a Working Instrument for a Working Musician, as you implied in your initial post. Personally, I would Look to Invest in Replacing both Pickups with an Ideally Matched Pair, Replace All the Potentiometers with the Correct CTS Pots and Capacitors too and the Output Jack with a New Switchcraft Replacement.

 

If you use the Proper Wiring Diagram and Pick your Replacement Parts Judiciously, I would be very surprised if you didn't end up with a Far Better Sounding Guitar than you ever owned Before. It's possible some may argue that if this Guitar is a Collectable, the Minimal Intrusion Necessary, is the way to go for Possible Devaluation Reasons. I fully understand that point of view, and would not argue with it if that is the Value Choice you make. However, consider this.

 

You have already tried a "Piecemeal Approach" to these this Tonal Problems. This appears to have lead to into further Dilemma's, seemingly involving a Steady and Increasingly Costly Mission Creep, with an Instrument that you rely upon for your Gigs. If SO MANY Parts have given problems, then in my honest opinion, it is Highly Likely that all the Parts that have not as yet been replaced will need to be replaced in due order, and you will keep needing to go back to your Luthier time and time again for one problem after another. If you need this Instrument to be Trustworthy and Reliable. If you need this Instrument to provide you with a Killer Tone that people Note as Outstanding. If you want to fix the Problems once and for All. Then Replace the Pickups with an Ideally Matched Perfectly Suitable Pair, fit a Switchcraft Pickup Selector, CTS Potemtimeters and New Best Quality Capacitors, and New Screened Wiring along with a Switchcraft Jack Socket, and I would be very surprised if you don't own the Best Sounding Guitar you Ever Heard.

 

Yes it will Cost Time in Specific Component Research and Some Money, but I believe your Investment will be Handsomely Rewarded, and You and Your Listeners will Warmly Appreciate, the Scintillating Quality of your Fine Instrument, Every Time you Play.

 

There's no point in Being a Guitarist, and not sounding Stunningly Good.

 

If folk can see you have a Sensational Brand and Model of Guitar.

 

And it Sounds Poor, Who Will They Think is Responsible?

 

 

Good Luck Whatever you do.

[AlanC]

Quote: "The pickup failed pretty much straight after I replaced the bridge base so I didnt really get a chance to familiarise myself with the new sound. And also I'm not convinced that the bridge pickup is 100% right as it was intermittant when the fault emerged."

 

 

 

Alan. We only have the information you impart to go on. Thank you for the Additional Facts.

 

I think it's worth investigating the Brand Quality and Exact Specification of the Replaced Components as they make a difference.

 

However, if you have a Pickup that is working intermittently, something is broken, obviously at times making some kind of contact and clearly, sometimes not.

 

It's easily possible that a Circuitry Failing within the Faulty Pickup might be the cause of the Complete Internal Wiring of the Humbucker not providing the Full Specified Output of the Design.

 

Under such circumstances, it would be entirely unsurprising if there was a Significant Thinning of the Tonal Quality the Pickup Provides. For many years, certain types of Guitarist have sought Over-wound High Output Pickups which give a Full Fat Tone.

 

Session Players and Older Top Guitarists often have Vintage Instruments at their disposal which feature Lower Pickup Windings with a concomitant Lower Output, and a Strikingly Clear, Bright Tone. For instance, we know that with a Coil Tap Switch changing a Humbucker to a Single Coil we get a Brighter, Clearer Tone. Even Bass Pickups do this.

 

These are simply analogies to make the point that if for any reason a Certain Part of one of the Pickups, is not Working as it should, providing the Full, Specified Circuit, working as they were Designed to. That in itself might provide the Thinness of Tone that is bothering you, and whatever is done to the Pots, they can't fix that problem inherent to the Pickup.

 

To be entirely Honest, and I write this with the greatest possible respect. If One Pickup has needed to be replaced with "something", and another one is Faulty, and certain of the Potentiometers Fitted to the Instrument have needed to be Replaced. If this is a Working Instrument for a Working Musician, as you implied in your initial post. Personally, I would Look to Invest in Replacing both Pickups with an Ideally Matched Pair, Replace All the Potentiometers with the Correct CTS Pots and Capacitors too and the Output Jack with a New Switchcraft Replacement.

 

If you use the Proper Wiring Diagram and Pick your Replacement Parts Judiciously, I would be very surprised if you didn't end up with a Far Better Sounding Guitar than you ever owned Before. It's possible some may argue that if this Guitar is a Collectable, the Minimal Intrusion Necessary, is the way to go for Possible Devaluation Reasons. I fully understand that point of view, and would not argue with it if that is the Value Choice you make. However, consider this.

 

You have already tried a "Piecemeal Approach" to these this Tonal Problems. This appears to have lead to into further Dilemma's, seemingly involving a Steady and Increasingly Costly Mission Creep, with an Instrument that you rely upon for your Gigs. If SO MANY Parts have given problems, then in my honest opinion, it is Highly Likely that all the Parts that have not as yet been replaced will need to be replaced in due order, and you will keep needing to go back to your Luthier time and time again for one problem after another. If you need this Instrument to be Trustworthy and Reliable. If you need this Instrument to provide you with a Killer Tone that people Note as Outstanding. If you want to fix the Problems once and for All. Then Replace the Pickups with an Ideally Matched Perfectly Suitable Pair, fit a Switchcraft Pickup Selector, CTS Potemtimeters and New Best Quality Capacitors, and New Screened Wiring along with a Switchcraft Jack Socket, and I would be very surprised if you don't own the Best Sounding Guitar you Ever Heard.

 

Yes it will Cost Time in Specific Component Research and Some Money, but I believe your Investment will be Handsomely Rewarded, and You and Your Listeners will Warmly Appreciate, the Scintillating Quality of your Fine Instrument, Every Time you Play.

 

There's no point in Being a Guitarist, and not sounding Stunningly Good.

 

If folk can see you have a Sensational Brand and Model of Guitar.

 

And it Sounds Poor, Who Will They Think is Responsible?

 

 

Good Luck Whatever you do.

 

Anthony thank you once again. I actually agree with much of what you say.

 

I have always pursued sound/tone quality irrespective of the value of the instrument. This particular archtop is a really good Gibson Tal Farlow which I have been using to gig with for about the last 4 years. As you say I've had a bit of a piecemeal approach but initially changing the bridge seemed like a good idea and it did improve the tone and individuality of the guitar. But now that I've had some technical problems with the pickup etc and after changes designed to overcome the problems, the tone is now just not good enough. So replacing the '57 classics might just be the way to go. I'll talk to my luthier.

 

I also own an L4CES which had '57 classics in it which I thought were terrible and I put Benedetto S6's in it and it made it really good (albeit that I don't use it for gigs). So I may try Benedetto's again. I do like '57 classics but they can vary a lot. Not sure what I'll do just yet. But thanks for your help. Much appreciated.

[AlanC]

Quote: "The pickup failed pretty much straight after I replaced the bridge base so I didnt really get a chance to familiarise myself with the new sound. And also I'm not convinced that the bridge pickup is 100% right as it was intermittant when the fault emerged."

 

 

 

Alan. We only have the information you impart to go on. Thank you for the Additional Facts.

 

I think it's worth investigating the Brand Quality and Exact Specification of the Replaced Components as they make a difference.

 

However, if you have a Pickup that is working intermittently, something is broken, obviously at times making some kind of contact and clearly, sometimes not.

 

It's easily possible that a Circuitry Failing within the Faulty Pickup might be the cause of the Complete Internal Wiring of the Humbucker not providing the Full Specified Output of the Design.

 

Under such circumstances, it would be entirely unsurprising if there was a Significant Thinning of the Tonal Quality the Pickup Provides. For many years, certain types of Guitarist have sought Over-wound High Output Pickups which give a Full Fat Tone.

 

Session Players and Older Top Guitarists often have Vintage Instruments at their disposal which feature Lower Pickup Windings with a concomitant Lower Output, and a Strikingly Clear, Bright Tone. For instance, we know that with a Coil Tap Switch changing a Humbucker to a Single Coil we get a Brighter, Clearer Tone. Even Bass Pickups do this.

 

These are simply analogies to make the point that if for any reason a Certain Part of one of the Pickups, is not Working as it should, providing the Full, Specified Circuit, working as they were Designed to. That in itself might provide the Thinness of Tone that is bothering you, and whatever is done to the Pots, they can't fix that problem inherent to the Pickup.

 

To be entirely Honest, and I write this with the greatest possible respect. If One Pickup has needed to be replaced with "something", and another one is Faulty, and certain of the Potentiometers Fitted to the Instrument have needed to be Replaced. If this is a Working Instrument for a Working Musician, as you implied in your initial post. Personally, I would Look to Invest in Replacing both Pickups with an Ideally Matched Pair, Replace All the Potentiometers with the Correct CTS Pots and Capacitors too and the Output Jack with a New Switchcraft Replacement.

 

If you use the Proper Wiring Diagram and Pick your Replacement Parts Judiciously, I would be very surprised if you didn't end up with a Far Better Sounding Guitar than you ever owned Before. It's possible some may argue that if this Guitar is a Collectable, the Minimal Intrusion Necessary, is the way to go for Possible Devaluation Reasons. I fully understand that point of view, and would not argue with it if that is the Value Choice you make. However, consider this.

 

You have already tried a "Piecemeal Approach" to these this Tonal Problems. This appears to have lead to into further Dilemma's, seemingly involving a Steady and Increasingly Costly Mission Creep, with an Instrument that you rely upon for your Gigs. If SO MANY Parts have given problems, then in my honest opinion, it is Highly Likely that all the Parts that have not as yet been replaced will need to be replaced in due order, and you will keep needing to go back to your Luthier time and time again for one problem after another. If you need this Instrument to be Trustworthy and Reliable. If you need this Instrument to provide you with a Killer Tone that people Note as Outstanding. If you want to fix the Problems once and for All. Then Replace the Pickups with an Ideally Matched Perfectly Suitable Pair, fit a Switchcraft Pickup Selector, CTS Potemtimeters and New Best Quality Capacitors, and New Screened Wiring along with a Switchcraft Jack Socket, and I would be very surprised if you don't own the Best Sounding Guitar you Ever Heard.

 

Yes it will Cost Time in Specific Component Research and Some Money, but I believe your Investment will be Handsomely Rewarded, and You and Your Listeners will Warmly Appreciate, the Scintillating Quality of your Fine Instrument, Every Time you Play.

 

There's no point in Being a Guitarist, and not sounding Stunningly Good.

 

If folk can see you have a Sensational Brand and Model of Guitar.

 

And it Sounds Poor, Who Will They Think is Responsible?

 

 

Good Luck Whatever you do.

 

Hi Anthony. I very much appreciated your advice. So I've finally got the guitar to a really good spot. It took 2 further goes with the guitar tech.

 

So just in summary after a pickup failure at the bridge and no sound in the middle position when blending both pickups, I replaced the tone pot, switch and capacitors, the sound became thin and unattractive. A sound quality/tone that was unacceptable to me

 

A week before the sound failure I'd also just changed the bridge base to ebony to match the ebony bridge I put in 6 months ago. So I was a bit suspicious that moving from rosewood to ebony may have been a contributing factor.

 

So the journey began to regain the great tone the guitar once had. I tried to buy 2 matched '57 classics as you suggested but they (Gibson) apparently stopped making matched '57 classics in 2011 so I didn't explore this option to buy another set of '57 classics although this could have become an option if I couldnt regain an attractive tone.

 

In the next visit I replaced the 2 x '57 Classics (thinking that one of the pickups may have been faulty) with a Benedetto S6 and in the bridge a Seymour Duncon '59. The result was still very disappointing. So I took the guitar back and replaced both pickups with Benedetto B6 pickups and the tech also decided to examine and fix the treble bleeds. No idea exactly what fixing the treble bleeds means. Fortunately i already owned these pickups and just swapped them from one guitar to the Tal Farlow.

 

The result has been very good. Interesting tone, great clarity, rich warm and mellow tone, great treble tone on the treble strings around the 10 to 12th frets. Chords tones can all be heard and the sound is not overly muddy. I dont need to wind the tone controls to below 5 to get a warm mellow sound. All in all a good result. I'm playing at a jazz festival next week and will use this guitar. so that's a good endorsement.

 

Thanks very much for your advice. I actually took my tech thru your advice as a starting point on this journey. Much appreciated.

[SteveFord]

It sounds like he stuck the wrong tone pots in there the first time around.

[AlanC]

1423306770[/url]' post='1625865']

It sounds like he stuck the wrong tone pots in there the first time around.

 

Lol if that's the case Its cost me a fair bit of time and effort

[nprenger]

It's possible that your luthier simply had a bad solder joint. I didn't do the greatest job of soldering in one of my new pickups when I replaced them and rewired my Les Paul, and the sound was thin and trebly. After I resoldered it, it sounded fat and round like it should. Maybe this is what he changed when he said that the treble bleed circuit wasn't quite right. Another possibility is that he adjusted the treble bleed's capacitance and / or resistance values, as those affect the frequencies that are passed through when you roll back the volume control.

 

nprenger