Causes of a sour tone?

[Dave Locher]

I am finally getting close to being able to post photos of the guitar build I started over 3 years ago (really excited!), but in the meantime I have a question about the guitar that I've used as the model for my build:
It's a heavily modified mid-'70s Gibsom Marauder (bolt on maple neck, heavy alder or mahogany body, typical Gibson hardware) with a 1978 Ibanez V-2 neck pickup in the bridge position, an aluminum pickguard and a bone nut. I also installed a mini toggle to bypass the tone control because the original tone pot really muddied up the tone. (It was a 250k, probably because it came with a single coil pickup in the bridge position and a really shrill humbucker in the neck position.)

The problem is I hear odd or harsh harmonics when playing with distortion. I replaced both pots because I thought that would solve it. I have adjusted and checked the intonation. No change. At this point the most likely culprits I can think of are: position of the pickup, something amiss with the neck, or wear to the bridge.
I just eyeballed the pickup position when I mounted it so that seems most likely. I'd have to make a new pick guard to move it, so before I do can anyone tell me if pickup position can cause odd tonal issues? I used this same pickup in two other guitars so I know it's not the pickup.
Any help?

[Gordon Bellerose]

I have some questions before I try and give you any kind of answer.

1. Are all pickups humbuckers now? If not, what configuration do you have?
2. If so, are they both wound the same way?
3. Do you get the overtones on "Bridge Only", "Neck Only", or "Both" ?
4. Is the aluminum pickguard grounded?
5. How close to the strings are the pickups adjusted?

[Dave Locher]

I have some questions before I try and give you any kind of answer.

1. Are all pickups humbuckers now? If not, what configuration do you have?
2. If so, are they both wound the same way?
3. Do you get the overtones on "Bridge Only", "Neck Only", or "Both" ?
4. Is the aluminum pickguard grounded?
5. How close to the strings are the pickups adjusted?

1. Yes, both humbuckers.
2. Yes, both wound the same way.
3. Not positive, but I think bridge only.
4. Yes, it is grounded.
5. I'm out of town so I can't measure it, but I'd guesstimate bridge pickup is maybe 1/8" or so below the strings.
I guess I should mention that it's pretty mild - no one seems to notice but me but it is definitely there.

[Mark Swanson]

How close to the bridge is the lead pickup?

[Gordon Bellerose]

One more question.

Does that guitar have a Tune-O-Matic bridge?
If so, it could be the bridge pickup is also picking up the overtones that happen behind the bridge.

[Art Davila]

Plus one
on the tunomatic bridge can you use a jimmy clip or something simular to mute the strings after the bridge and after the nut?

plus are you talking 70's classic rock distortion or high gain amp distortion?
Because that type of gain magnifies all the bad stuff so that,
what would not bother you at mild gain irritates the crap out you.

http://www.thejimmyclip.com/

Watch the video's they talk about what I think your hearing.

[Dave Locher]

Aha! I never thought about the strings behind the bridge, but I bet that's it! The Marauder has the "harmonica" Tom bridge, which means the stop tailpiece is further back than a typical Gibson (to clear the extra-wide bridge), which means there is more string behind the bridge than a Les Paul or SG.
As soon as I get home I'm going to muffle them and see if it solves the problem.
It's crunchy classic rock gain, not modern metal (1978 Randall amp head) but the pickup is very sensitive so I suspect that is exactly what is happening. I had a tremolo tailpiece guitar once that I put a strip of masking tape on the strings to solve this same problem. I can't believe it never occurred to me.

[Gordon Bellerose]

Let us know if that is the cause.

[Dave Locher]

Let us know if that is the cause.

Will do, but I won't have the guitar back in my hands until June 30. I've already ordered some pick guard plastic so I can relocate the pickup if this doesn't solve it for me.

[Dave Locher]

Nope. Not the problem. Although muting the strings behind the bridge does make a very slight difference it does not make my ears happy enough.
I think it's actually a problem with the intonation and/or fret buzzing. The bridge saddles are very worn, as are the frets, and one or the other seems to be causing issues. It think the string radius at the bridge no longer matches the neck radius.
I'm going to deal with both of those the first chance I get and see where that gets me.

[Gordon Bellerose]

If the intonation is out, you will play out of tune.
If the saddles are rounded, you will get buzzing, and play out of tune.
What happens, is the string will buzz against the edge that is rounded.
Just the same as the nut must have a square edge facing the fret board, so must a bridge saddle.

[Art Davila]

Now that your back can you post pictures of the frets being worn, and the position of the pickup to the bridge?
Also Gordon asked questions 3 and 5 which you did not say what your findings were, in that respect.

Do you hear any rattle if you hit the neck with the side of your fist?
I remember another member had a rattle from a truss rod which, he would hear when he played hard.

[Dave Locher]

I tried to attach photos but cannot figure out how to make them small enough on my iPhone. The guitar has a lot of miles on it! It was already modified and heavily used when I got it, which allowed me to further modify it with no guilt and I then played the heck out of it for several years and then sold it to a friend who used it as his main guitar for a few years.
Bridge pickup is 1/8" below strings.
No truss rattle.
Hard to say if the odd sound occurs with the neck pickup because it turns to pure mud when I play hard in the neck or both-pickups position. (This guitar puts out a lot of lows & mids and this particular pickup works great for notes but not so much for chords.)
I suspected the bridge pickup position because I cocked it back when I installed it back around 1992 or so.
I just played it hard unplugged and I believe the bridge saddle for a couple strings might be the problem. Does anyone know where I can get replacement saddles? I'd hate to replace the whole bridge - it's just about the only original part on the whole guitar! (And vintage Gibson harmonica bridges go high on eBay despite their only being used during the low-quality years.)

[Gordon Bellerose]

The bridge saddles can be filed just like the nut.
You can square the front edge off, and then file a groove to the correct height for your fingerboard curvature.
Then simply adjust the height of he bridge.

[Dave Locher]

Good point. I think that may work if I swap some of the saddles' positions first, because the G, B, and E string saddles are really low - those strings sit well below the tops of their saddles.

[Dave Locher]

I am embarrassed to admit this, but it turns out that most of the problem was my tuner. It just wasn't accurate enough. I bought a new tuner when I was finishing up my first build a couple weeks ago and suddenly my Gibson sounds okay.
I still have some fret work and bridge saddle work to do, but apparently the majority of the problem was that I have been setting my intonation with a tuner that wasn't precise enough to get it just right. On the one hand I feel pretty dumb for not figuring it out sooner, but on the other hand I'm relieved to have a solution and thankful for all the suggestions and help I received on this forum.
(If I'd known tuners were so inexpensive these days it would have been the FIRST thing I tried!)

[Dave Locher]

Final update: problem 100% fixed/solved.
Getting a more precise tuner did allow me to set the intonation more accurately, but that just made the problem less noticeable. It still sounded "wrong" to me. Yesterday I finally found someone in my town who knows how to properly level and crown frets. That was the last piece of the puzzle. As a couple of you correctly guessed, some of my frets were flatted to the point where they were causing the note to be off just a bit just on that fret. Now the guitar sounds right all over the neck on all strings.
Thank you to everyone who helped.

[Gordon Bellerose]

Thanks for letting us know the final result.
Yep. Flat, wide frets can certainly sour a note.