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Totally confused - help!

T

Tim1

Sep 9, 2005
4,531
3,750
New Zealand
#1
I have been asking about this but the issue seems to have changed, hence the new thread. The neck pickup on my 63 Jazz sounds thin and is down in volume compared to the bridge pup. I thought it was a pickup issue but when I removed the hot wire from the pot and connected directly to the amp, by passing the control plate, the bottom end and volume returned indicating I assume that the pup is okay. Now listen to this - I cannot get a reading from it, the bridge reads 8.3 but nothing on the neck. I cannot understand this, since it sounds fine when the control plate is bypassed. I even tried connecting the hot (white) wire direct to the output jack with an alligator clip and plugging in the cable to it - the thinner tone returned!!!
I have considered that maybe it is an earth issue, yet the earth links all test fine. Just cannot get my head around this one, electronics are meant to be logical I thought. Surely if the pickup is not dead I should get some reading from it, and it isn't dead because I am getting a healthy signal through the amp.
Aaaaargggghhh......:nailbiting::nailbiting::nailbiting:
Logic tells me the bottom line is, if there is no continuity it must be f*****d. My ears tell me it works - is it possible for there still to be a signal in these circumstances?
 
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#2
I am assuming that you attempted to measure DCR? If so, it is possible that there is a break somewhere in the winding. Capacitive coupling would allow a faint signal to pass through, but you would not see a DC resistance, since capacitance blocks DC. Something like this would best be diagnosed with an analog Ohm meter. Watch carefully for a sudden deflection in the needle, at the moment the leads are connected.
 
#3
Yes I was measuring DCR. I just used a different multimeter and I am getting a reading now, but it is not constant and goes up and down slowly from 3 to about 10 before settling eventually somewhere in the middle. However the bridge pickup sets straight to 8.1. It has me beat - I have put alligator clips to direct wire each pickup to the amp and the neck pup sounds wonderful. I have not desoldered its earth wire, so I may try that next as maybe it is adding some capacitance somewhere when attached to the input jack? There is also a second earth wire coming from the neck pickup which is soldered to the bottom of the control cavity, I assume that is from a grounding plate underneath the pickup.
Guess I will just have to go through a process of elimination, have both wires desoldered and slowly introduce things. The issue seems to be less one of volume than one of a low end roll off perhaps, giving perceived drop in volume. I am trying to figure whether maybe something is introducing capacitance or resistance which might cause this, yet it seems weird that it would not affect both pups. Ah well, I will sort it eventually. I get this feeling it is the pickup, but if that is the case why does it sound so good when it is wired direct?
 
#5
Hopkins said:
If you cant get a solid reading on the pickup, I would say you have already found the problem. The coil is damaged.
Click to expand...
I think you must be right, I just can't get my head around the fact that it is perfectly fine when I run it direct and bypass the control panel. I think I can get a Seymour Duncan Antiquity 2 so perhaps I will pop one in and see what happens.
 
#6
Tim1 said:
I think you must be right, I just can't get my head around the fact that it is perfectly fine when I run it direct and bypass the control panel. I think I can get a Seymour Duncan Antiquity 2 so perhaps I will pop one in and see what happens.
Click to expand...
imo an antiquity 1 wound to around 8k would be a better match for your bass. before i broke down and had the neck pickup in my 62 jazz rewound, i tried everything in there. duncan antiquities definitely won out. the softer upper midrange of the alnico2 in the antiquity 1 pickup would better suit the sweetness of the orginal pre cbs pickups.

im also very happy with the sound of the original neck pickup after mj at the duncan custom shop rewound it. if you ask them to inspect it before the rewind, theyll see if its anything more simple. one coil in the pickup from my 64 p bass kept cutting out and eventually stopped working. i sent it in and it turned out it didnt need a rewind, just refreshing of the solder at the eyelets. before i sent it in, i had tried soldering on new leads myself but still couldnt get it to work.
 
#8
The Duncan pup arrived today so I have installed it.
The installation was interesting – no practical problems, pup was a tad boomy which I could live with but when I put both pups on full the sound again became thin and quieter (although the Duncan had plenty of volume by itself which was lacking in the original)! Sounded fine and low end returned with both on the moment I backed one off a tad.
Anyway, after a wine and much head scratching I could only think that polarity or phasing must be an issue. On the off chance I reversed the leads on the Duncan so that yellow was earth, black was live and lo and behold - sweet music, everything balanced nicely. The bass is sounding and playing as it should - a sweet 63 J :hyper:.
The Duncan is an Antiquity 1 which reads 8.45k, not too far away from the 8.3 on the bridge pup so balance is good and tonally there is no mismatch. I can only assume that at some stage someone has reversed the polarity on the bottom of the bridge pup, or the Duncan is wired opposite which would be unusual but not impossible.
I was tempted to put the original back and try that again with the polarity reversed, but there seemed little point since it lacks a constant reading on the meter and swings all over the place. It definitely needs a rewind.
Anyway, band practice on Saturday and I am looking forward to giving her a whirl. Thanks for the advice, Narud, the Antiquity 1 does seem a good match for the original neck pup and does not draw attention to itself at all as a newer pup.
The world of vintage basses is intriguing/funny/frustrating/rewarding.........you name it. But the journey has certainly been worth it for me in the case of this bass. I feel that we have bonded;).
 
#9
Tim1 said:
The Duncan pup arrived today so I have installed it.
The installation was interesting – no practical problems, pup was a tad boomy which I could live with but when I put both pups on full the sound again became thin and quieter (although the Duncan had plenty of volume by itself which was lacking in the original)! Sounded fine and low end returned with both on the moment I backed one off a tad.
Anyway, after a wine and much head scratching I could only think that polarity or phasing must be an issue. On the off chance I reversed the leads on the Duncan so that yellow was earth, black was live and lo and behold - sweet music, everything balanced nicely. The bass is sounding and playing as it should - a sweet 63 J :hyper:.
The Duncan is an Antiquity 1 which reads 8.45k, not too far away from the 8.3 on the bridge pup so balance is good and tonally there is no mismatch. I can only assume that at some stage someone has reversed the polarity on the bottom of the bridge pup, or the Duncan is wired opposite which would be unusual but not impossible.
I was tempted to put the original back and try that again with the polarity reversed, but there seemed little point since it lacks a constant reading on the meter and swings all over the place. It definitely needs a rewind.
Anyway, band practice on Saturday and I am looking forward to giving her a whirl. Thanks for the advice, Narud, the Antiquity 1 does seem a good match for the original neck pup and does not draw attention to itself at all as a newer pup.
The world of vintage basses is intriguing/funny/frustrating/rewarding.........you name it. But the journey has certainly been worth it for me in the case of this bass. I feel that we have bonded;).
Click to expand...
good to hear! id probably want the duncan to read around 8k to match well with the old pickup. less wire on the newer magnets seems to sound closer to the old magnets with more wire to me.

old fender pickups have the start of the coil as the hot lead. this leads to buzzing when you touch the pole pieces. duncans are the opposite and dont buzz when you touch the poles. this caused the out of phase wiring even though the duncan was wired "correctly". i reverse the leads on all my old fenders so the poles dont buzz.
 

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