Thin Tone from my '72 Jazz

[s_wood]

I have a '72 Jazz which produces a lot less low end than my other '72 Jazz, or my '64. The pickups are original. I don't think that the pickups are out of phase - I know what that sounds like because I've dealt with that problem before, and I also have a Ripper with an out-of-phase setting. This bass doesn't have that "hollow" out of phase sound, it just lacks low end, as if one backed way off on the bass knob on the EQ of an active bass. Plus, the problem is with both pickups, whether both are at max volume, or any combination and even with one off. The tone control works. Pickups are the correct height.

I am out of ideas. What should I try to troubleshoot next?

 

[ctmullins]

Does it sound thinner than your other basses when you play it unplugged? If so, then it isn’t an electronic issue. You may be able to mitigate it with different strings - strings are one of the primary components in the recipe for tone - but this may just be part of this instrument’s inherent voice.

 

[JeezyMcNuggles]

I have a '72 Jazz which produces a lot less low end than my other '72 Jazz, or my '64. The pickups are original. I don't think that the pickups are out of phase - I know what that sounds like because I've dealt with that problem before, and I also have a Ripper with an out-of-phase setting. This bass doesn't have that "hollow" out of phase sound, it just lacks low end, as if one backed way off on the bass knob on the EQ of an active bass. Plus, the problem is with both pickups, whether both are at max volume, or any combination and even with one off. The tone control works. Pickups are the correct height.

I am out of ideas. What should I try to trouble shoot next?

Suck the neck to the body. It helps with bottom and sustain. Tune it, then loosen the neck bolts and wait for the pop. Tighten it back up.

 

[winegamd]

What is your pickup height compared to the other two? What value pots are in it?

 

[pepj]

If the 72 is all original, your hands are tied.
Make sure what you take out can go straight back in.

But also, sometimes Fender got it all wrong.
How much is a 72 worth as it stands because an original could collect decent money.
If it has been messed with, then the damage is done.

I'd do simple easily reversable mods at first like pickup height.

 

[s_wood]

The bass is all original, AFAIK. I don't want to modify it by swapping parts, unless one of the parts has failed and is the source of the problem. The pickup height is 7/16" on the bass side, right in line with factory specs.

 

[winegamd]

7/16" seems pretty far away to me, but then I have modern humbuckers and run them 1.5-2mm from the string when fretting at the 24th fret.

I would try raising the pickup, up to 1/8" (when fretting at the last fret) if necessary. Specs are great for factory repeatability, but settings to achieve a preferred tone can vary widely between players and instruments.

I agree with Vinny and Joey at Fodera. Pickup height is best measured by your ears.

There is not really a tone curcuit component that could fail and cause more treble. So, it may just be the characteristics of that bass. Changing the strings may be your only option if an electronics swap is out of the question.

 

[pepj]

Nearly half an inch from the strings?
Mine would never be more than a quarter onch from strings.

 

[dwizum]

The pickup height is 7/16" on the bass side, right in line with factory specs.

Where are you getting that factory spec from?

Here's Fender's setup guide, which covers pickup height:

How do I set up my bass guitar properly?  · Customer Self-Service

Pickup heights are spec'd in the range of 6/64" - 8/64" depending on the model. Your 7/16" is much further away. Maybe you typo'd and meant 7/64"?

Can we see some photos of the backs of the pickups and control plate? Basses work on incredibly weak signal strengths, sometimes a bad solder join or other wiring issue can cause problems like this.

 

[s_wood]

Pickup heights are spec'd in the range of 6/64" - 8/64" depending on the model. Your 7/16" is much further away. Maybe you typo'd and meant 7/64"?

Ayup… brain cramp! The pickups are 7/64” below the strings. Here’s the control cavity.

 

[iiipopes]

In the early 80's I had a '75 J-bass which the neck pickup started to sound thin. A winding let go. I don't know what happened in the '70's with the winding machines or wire source, but it is common knowledge that occasionally a 70's J-bass pickup will just let go. I hope this has not happened to you, as if you can keep it original it is worth more than a replaced or rewound pickup, even if done correctly.

 

[dwizum]

Nothing awful in that photo and it looks original. Do you have a multimeter? Would be handy to check the pickups and pots.

 

[narud]

get a multimeter. early 70's pickups are notorious for shorting. whoever their wire supplier was at the time was providing wire in which the insulation would break down over time and the copper wire would short against a pole piece. when this happens, they dont die completely, but will have low output with no low end. while this may not be the case in your situation, checking with a meter is an easy way to find out.

 

[Funkinthetrunk]

get a multimeter. early 70's pickups are notorious for shorting. whoever their wire supplier was at the time was providing wire in which the insulation would break down over time and the copper wire would short against a pole piece. when this happens, they dont die completely, but will have low output with no low end. while this may not be the case in your situation, checking with a meter is an easy way to find out.

I had the same issue with my Stingray, Sabre and Jazz from that era. Simple rewind fixed all.

 

[s_wood]

get a multimeter. early 70's pickups are notorious for shorting. whoever their wire supplier was at the time was providing wire in which the insulation would break down over time and the copper wire would short against a pole piece. when this happens, they dont die completely, but will have low output with no low end. while this may not be the case in your situation, checking with a meter is an easy way to find out.

Sounds like a good idea. How do I do that without desoldering the pickups?

 

[iiipopes]

Sounds like a good idea. How do I do that without desoldering the pickups?

Unfortunately, you don't. Unsoldering the white wire from the volume pot lug is the least invasive way to do it. Do one pickup at a time so you know where to solder it back when you are done. This isolates the pickup from the rest of the circuitry to get a more accurate reading. It should read @ 7 to @ 8 kohms DC resistance, give or take, depending on when the pickup was made. What you are looking for is not a particular number, unless it is way outside these parameters. What you are looking for mostly is a stable reading in the ballpark. If the multimeter doesn't make a reading, or if it wobbles or the numbers keep churning and won't settle down, that lets you know the pickup needs attention, whether a rewind or replacement.

 

[s_wood]

Thanks!

 

[Bass4ThePublic]

Yep 70’s fender pickups had both decaying wire and shoddy lacquer potting, send it to Tom Brantley and have rewound in plain enamel wire and wax potted.

 

[jymyben]

Yep 70’s fender pickups had both decaying wire and shoddy lacquer potting, send it to Tom Brantley and have rewound in plain enamel wire and wax potted.

was going to also suggest a brantley rewind…

 

[jza57]

I would have a good tech see if your pickups have become demagnetized . That is if you want to keep it stock. If your pickups check out then have them check you your pots. If it were me I would start checking here before rewinding pickups . If you have a multitester YouTube testing procedures.