Jazzmaster hums like a hummer.

[ThatBliss]

My 60s Lacquer Jazzmaster is about two days from being thrown out of a window. It hums and buzzes like a total bitch. I'm not a newb- I know what I'm doing with wiring and this is impossible.

Things as a list:

-The guitar hums, louder than the standard single coil hum and much louder than my other guitars (US Strat and AV65 Jaguar)
-Whenever I touch something metal (bridge, strings, pickup screws, switch surround) the hum goes. Magic. Same for poking the metal barrel of my lead.
-Keep your hands on the strings you might say. I play in open tunings live and often both hands are not on the strings, when i touch them again the hum goes with a pop.
-I've even noticed when I touch the on/off switch of my amps the hum goes too.

Things I've done

-Rewired the whole guitar. Twice. It currently has a pro wiring harness in it. Even wired without the rhythm circuit straight to switch and pots it was the same.
-Replaced the pickups. Handwound and lovely.
-Pulled the thimbles out and made sure they are grounded to the bridge. Done.
-Checked the whole thing with a DMM, resistance is zero or close to zero across the whole guitar.
-Tried different amps. Different parts of my house. At gigs indoor and outdoor. Still the same.
-Oh and it has a nice mastery bridge and tremolo, cos i like nice things to work properly.

Things I haven't done

-Looked into the shielding of the guitar, the black shielding paint is only over half of the neck pickup cavity. Problem?
-Replace the pickguard- everything else has been replaced except this. It has a nice sticker on it so I don't want to throw money at it and lose my sticker. The hum and pop is still there when the wiring harness is not joined to the pickguard.

I'm at a loss and it's really pissing me off. Does anyone have any ideas how to fix this? It's gotten worse since I got the guitar and it's currently sitting in bits on my desk as I trouble shoot it. I don't want to mess around with things that wont work and the internet is useless, i've been searching for weeks.

Help me offset- you're my only hope.

[Dennism]

Looks like you've exhausted just about every option you have. Do you have a qualified guitar repairman or tech in your town or city? seems to be your best bet. Good luck!

[ThatBliss]

Looks like you've exhausted just about every option you have. Do you have a qualified guitar repairman or tech in your town or city? seems to be your best bet. Good luck!

Nope I really don't. Hence me asking the wonderful internet. I'm going to blame the shielding, it CANT be the wiring or grounding now. I think.

[andy_tchp]

Whenever I touch something metal (bridge, strings, pickup screws, switch surround) the hum goes. Magic.

No. Not 'magic'. It's working as designed.

Jazzmasters are noisier than other single coil guitars like Strats and Jaguars.

Is the middle position with both pickups on quiet? You might need to use that setting for the songs you play which involve you not touching the strings at all (??)

[Larry Mal]

The shielding paint in half the cavity can certainly be a problem. Maybe look into some better shielding, either paint, or copper tape, or even those brass tubs that the vintage ones have.

Noise being noise, though, I'm still scratching my head that it goes away when you touch it. I wonder if everything is running to ground as it should be. Maybe it would be a good idea to get a multimeter and check the continuity of various components.

[andy_tchp]

^ Does the noise level on your Jazzmaster/s not decrease while you touch the strings Larry?

Mine exhibit the same behaviour, and they're shielded up the wazoo. It's pretty rare that I'm playing something and not touching the strings though.

(OP indicated they'd already checked continuity with a DMM.)

[Larry Mal]

I mean, maybe... I never really noticed it a whole lot. I use the middle position mostly, though.

But he's talking about a lot of noise that goes away when he touches the string. That tells me something.

The question of whether or not the guitar gets any more quiet in the middle position is a good one.

[andy_tchp]

But he's talking about a lot of noise that goes away when he touches the string. That tells me something.

Yes, me too - that it's working as designed.

Seen this exact thread play out 1000 times where folks spend an inordinate amount of time trying to fix something that isn't broken, expecting the Jazzmaster to be as quiet as their Strat/Tele/some other guitar that doesn't have a pair of (comparatively) enormous wide pickup coils hanging (usually) well outside of the pickguard that do a great job of attracting interference/noise.

Shielding the cavity or pickguard will not address noise being picked up/generated at the pickups...

[Larry Mal]

I'm taking it on faith that he considers this to be more than what the situation should be. It seems he knows his stuff. Maybe wait for clarification.

Can you record the noise?

[Larry Mal]

Shielding the cavity or pickguard will not address noise being picked up/generated at the pickups...

No, but bad shielding- like a partially painted cavity that might not be grounded- can make matters worse.

Although I did miss that he'd gone through the thing with a multimeter.

[mackerelmint]

If the noise is being generated at the pickups and there's no fault in the wiring or shielding, then try this:

Undo the pickup leads going to the selector switch. Twist them together along the length, taking up as much of the slack as you can. Solder them back to where they were. Wiring runs in amps are done this way to help reject noise. I tried it in my jazzmaster when installing a new set of pickups, and didn't feel like cutting the leads. So I just wound them together to take up the slack. It doesn't hum at all. YMMV, since I haven't heard yet from anyone else having tried it. I just know that I did it, and have a non-noisy jazzmaster.

[andy_tchp]

Mackerelmint's suggestion of twisting the leads together to aid noise rejection is a good one, and I prefer to do this rather than cutting pickup leads short.

I'm taking it on faith that he considers this to be more than what the situation should be. It seems he knows his stuff. Maybe wait for clarification.

And I don't? Shrug. I've been doing this stuff for a while... particularly Jazzmasters, for well over a decade.

Jazzmaster pickups, especially 'vintage' style, are noisy. (Funnily enough I only notice this if I've been playing something else like my ASAT or SC-3 for an extended period. When I played nothing but Jazzmasters all the time I didn't notice the noise at all.)




Anyway, best of luck guys

[sunburster]

Yeah, if you touch metal on the guitar and the noise goes away, that means the guitar is properly grounded. To reduce the hum you hear when you aren't touching the strings, you can try to shield the guitar better. Make sure the pickguard is fully shielded on the back (MIM pickguards are NOT fully shielded from the factory, unlike MIJs and AVRIs), and redo all the cavities with copper tape or vintage brass tubs (if they will fit -- not sure if MIM's have different cavity dimensions). JM pickups are noisy though, as mentioned by others above, so you can only reduce the noise so much by shielding.

My MIJ and AVRI62 JMs are pretty quiet, the AVRI62 is a bit quieter overall, but it has the brass tubs, which in my experience work a bit better than the shielding tape. My AV65 Jag is also pretty quiet.

[eigentone]

Some other stuff:

Use a good transformer for electrical isolation. There are dedicated products and less obvious products which will accomplish this, such as ABY boxes. I'd suggest a Radial BigShot ABY as an inexpensive entry.

Keep your distance from electronic devices, such as your cell phone and amps.

Use a power conditioner with your amps.

[windmill]

The shielding on the guitar is either insufficient or not connected properly.

You need to listen to Dave

https://www.youtube.com/watch?v=Qp-zFLylafE

The shielding bit starts at 5:00minutes

Get the copper tape or shielding paint out and cover all the cavities, make sure the the back of the pickguard is shielded and is in contact with the shielding of the other cavities.

Another example
https://www.youtube.com/watch?v=3dCze6napLA

I have had this problem on every Jaguar I have had, shielding has eliminated the noise.

HTH