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I recently switched out a 250k volume pot on a strat. The problem is that the customer has voiced a complaint that since he got the guitar back he has noticed that he gets very little volume from both the low E and D strings on the neck and middle pickups ONLY. The bridge pickup is a JB jr. and that picks up the signal and sounds terrific through an amp. Acoustically the guitar sounds just fine which is what makes me think that the problem lies somewhere within the electronics.

This guitar has two tone knobs and only the one master volume knob. I am far from an electronics expert but have a basic understanding. That being said, is it possible that somewhere there is a bad ground connection that is causing these two strings to find their way to earth faster than finding the output jack? I was under the impression that treble, not bass, generally "bleeds" off first.

I see some suspicion in the fact that the two problem pickups are the only ones that have tone controls, but I am also hesitant to find a problem in the tone controls due to the fact that only two strings seem to have volume issues.

The guy is bringing the guitar back tomorrow and my plan of attack is to check all connections visually and then with a meter.

Any advice regarding this issue would be very much appreciated!

Colin

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Colin,
firstly, pickups can be remagnetised and Fralins, for instance can be supplied with the poles unmagnetizied - I have not remagnetized pickups so I'm clueless on this (there is some stuff on the web I recall).

Now, having learned the hard way (a set of Fralins I was provided to install which checked out for continuity but were dead silent due to the poles being unmagnetized) I know the following: pickups can be demagnetized through shock, heat (grinding pole ends for instance) and exposure to AC electrical fields (such as big electric motors or purpose build degaussers -growlers) - also putting the pole of a strong magnet on the pole of the slug will either magnetise or demagnetise the slug depending on what magnetic orientation is used. So do not use another magnet to clean off magnetic filings from the pole pieces (such as those left by steel wool) - use gaffa tape to lift off the iron filings. And, if a pole piece is not magnetised the pickup will still work sorta - the adjacent poles will still sense the string and the string will appear weak but not dead silent. Also, a demagnetised pole does not attract a ferrous metal screwdriver when the tip is placed near the pole.

Stick to your guns Colin - the very fact that you point out something tone or noise-wize to a customer is a guarantee that it will become an issue as once heard (or not heard) the problem will become embedded in the mind and focused upon. The solution is to give the instrument a thorough going over when you take it on board - point out the issues to the customer and advise him of the possible causes and solutions. This prevents a lot of heartache down track with difficult customers and also reinforces your image as being particular with your good ones. Good luck with this one. Rusty.
there is a section in dan erliwines repair book on remagnetizing pickups
Thanks a lot Rusty, you've been a great help.

Luckily, this guy is turning out to be a pretty level headed guy - I had a tele of his in while he was at home with his shitty sounding strat, and he got the Tele back from me and was really happy with the work I had done on the Tele. So, overall I think the amount of emotional damage done is minimal and he just wants his strat to play the way it should so he can get it on the market and off his hands.

Wow, that was stressful!

I've now got an Ibanez Prestige in with a zero resistance bridge...you betcha it's getting plugged into the amp before I do anything to it.

Thanks again,

Colin
You might try re magnetizing one of the problem pickups just to see if that would help. Just make sure and get the polarity correct.

Ya never know. Stranger things have happened...

--eron
I'd contact Duncan. They've always been very helpful to me. I got a bad pickup from them once, and they replaced it without issue (I am a stocking dealer). Have you tried wiring them out of phase to see what happens?
try a new pickup?
I came in to this late but I wanted to make it known that Fender Stat pickups made before the mid 1960 DO NOT have adjustable pole pieces - the fine wire bears directly on the rough magnet outer casting and over a few years glue itself there - it wasn't until the mid '60s that a plastic bobbin was put between the pole piece and the wiring and allowed individual magnet adjustment. I went on vacation in Jamaica and let a customer -a "supposed" guitar repairman with a good local reputation - have my 1960 Strat to dress the frets while I was gone in return for a recapping job I'd done on his Fender Champ. But when I came to get the guitar I noticed that there weret two "strange' pickups on the instrument and asked him what was up. Well, totally without my permission, he had decided that my G pole piece's response was weak (it was made from wound G strings) and so he attempted to adjust up the level by grasping the pole piece with a pair of hemostats and pull the pole piece up. He was then suprised that my pickup went dead! Arrggggg, But were I really got pissed off was that he tried it on another of the pickups with the same results. He had only worked with later Fender pickups until that time and didn't know that these are essentially unadjustable for string height. It turned out "well enough" - I send the pickups to Lindy Fralin who rewound them and he also provided me with some compensation. But still the Stat doesn't sound like it did originally - originally the highs were to strong that there was no position to play in that didn't require some treble knock off but now I can play it with the tone all the way up. This was over 10 years and I've mostly gotten used to but sometimes I still awake from a dream where I remember the original sweet sound and get ticked off. To this day I understand how he screwed up the first pickup I just don't understand why he didn't quit after breaking the first one!!!

Don't mess with pre '60s pickups unless you know that they've been rewound and a plastic bobbin added.

Rob
Rob,

Man, thats a jaw-dropping story. Was the guy trying to pull the wool over your eyes in replacing the pickups? Seems like he should have more sense than that seeing as you are aparently an electronics tech, and it also seems like he would have been more concerned, considering the guitar he was working on!

Anyway, the strat I was working on was an early 90's strat and I didn't try to adjust the pole pieces.

Thanks for the story,

Colin
Amen to that, also one of the causes of pickup failure or weak output is when sweat/moisture wicks down the magnet pole pieces on these kind of pickups and corrodes the insulation on the adjacent coil wire which shorts to the magnet causing all sorts of trouble which is terminal (requires a rewind). A good reason not to give your old Fender (and others) a beer on a hot day!
Rusty,

That's an interesting point and makes total sense, never would have thought of it. And, man do I know I want that cold beer more than I want my guitar to have it!

Colin
Colin,

No he wasn't trying to pull the wool over my eyes - we were more of less friends - but instead he wanted to return a guitar to me that at least had three pickups in it but unfortunately he was somewhat self delusional as he just couldn't believe that it had happened as he had done the same adjustment on scores of other Strats - unfortunatly mine was the one where he found out the the pre-mid '60s Stats pickups were wound without a bobbin between the wire and magnet. As is I compromised for the Fralin rewounds cuz' I knew he didn't have the bucks to purchase working original pickups on e-bay, etc. (would have probably cost almost a grand then) but in the long run I still feel dissatisfied with the deal and, as I mentioned, still can't believe that he screwed up the second one. But some folks just don't subscribe the the "cautionary" principle which is pretty close to the physicians' "first do no harm." I tried to stay friends with him but he also screwed up in '"dressing the frets" on an old mandolin for me in return for other work and wound up removing so much fret metal that he really shortened the life of the frets. Finally I as his finances are poor - daughter got pregnant at 15 adding another mouth to the family - I recapped a Black Face Champ for him and only charged $25 - about 1/3 what the job wa worth - and he complained so I dropped him.

The sad thing is around here he actually has a good reputation as a repairman just because he's been doing it for so long but when I asked him about a Martin neck reset he'd never heard of such a thing? A truly small guppy in the Pacific!

I guess the lesson is that no matter how good a reputation someone has it's always good to solicit another quote especially now that the internet is available - but it behooves the owner to learn enough terminology to describe what repair is wanted and to do so honestly and accurately to solicit an opinion from some distance. This is not to be construed in any manner that one should not support their local folks - emergencies happen where you can't ship to CA and money/expertise need circulate locally - but we all need competition and we all get complacent. I've always though that a "kiss of death" response is "we've always done it that way." Kills a deal for me!

Rob
Hmmm, skimming this thread quickly again I couldn't tell if there original issue was ever fixed or not. Of course the way to check the pickup is to unsolder the pickup leads and solder them directly to the guitar output jack - this way nothing is between the signal source (pickup) and the amplifier. If the pickups then work on all strings then something else is bad but if not then it's the pickups. Systematic trouble shooting works by either starting from a point where you've got a signal to the amp and working backward or starting at the beginning of the signal chain and working forward until you get signal - been around in electronics since the 1920s or so and is still the standard method. "Parts changing" may work for those problems that are so common with particular instrument/amp/etc., that you're likely to hit more often than you miss but for all other repairs step-wise diagnosis prevents wasted time and hair pulling.

Rob

(over 35 years in electronics)

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