J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

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Tarquin
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J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by Tarquin » Sat Dec 04, 2021 11:35 am

Hi all. I have a VM Jazzmaster and it's great, but I find the bridge pickup a little bit hot but still on the 'thin' side as well, if that makes any sense. I like the sound of the Squier J Mascis Jazzmaster and have picked up a used J Mascis bridge pickup. There is only 1 wire coming from the Mascis pickup, as opposed to 2 wires going to the existing VM pickup. So where do I join the Mascis pickup to? Electronics is not my strong point but I can solder, so any help appreciated!

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by MayTheFuzzBeWithYou » Sat Dec 04, 2021 12:48 pm

If it has a metal cloth around the other wire this (the cloth) would be your ground.
I‘ve seen this in some parts-ads like below:
https://reverb.com/item/23893499-squier ... -harnesses

If this is not the case then you should at least have two solder points (and one cable missing) in that case - just resolder.
They made both versions.

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by Tarquin » Sat Dec 04, 2021 2:40 pm

Thanks, and yes the pickup is exactly same as the one in the link you sent. It looks like the core wire goes to the selector switch, so what do I do with the outer metal cloth? Does it have to be physically connected to work as the earth, and if so, where to? The same point on the switch? Thanks again, at least I know there isn't a wire missing now.
Last edited by Tarquin on Sat Dec 04, 2021 6:07 pm, edited 1 time in total.

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by MayTheFuzzBeWithYou » Sat Dec 04, 2021 2:52 pm

Happy to help!
Yeah, middle lug of the selector switch and from there you might bridge it to the back of your volume pot (grounding)...
But knowing/finding out that the braid=ground was the hard part. Now you might just follow whatever wiring you already have installed (or in mind) - best use a wiring diagram. There are some variations out there... just choose one! :)

Good luck! You can do this!

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by Tarquin » Sat Dec 04, 2021 6:07 pm

Thanks, I'll get there! So can I solder a wire directly to the cloth, and then run this off to solder to the volume pot to ground it?

I'm trying to visualise how the cloth is actually connected!

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by timtam » Sun Dec 05, 2021 4:42 am

The braided shield can be grounded to any grounded point in the guitar you like. In an actual Mascis with braided shield pickups (not all have this ?), the bridge pickup's shield is soldered to the already-grounded point on the toggle switch, while the neck's is attached to the grounded rhythm switch body. There's no electrical advantage to those locations, just that they are nearby to where the pickup hots (central conductors) are soldered.

I typically unravel the wire strands of the braided shield at the end of the wire (with a pointed pin-like tool to tease them out), then twist it into a single piece, tin it to hold the strands together, and then solder that to the ground point. Other people just solder the shield a little way back from the end of the wire to the ground point. It's a good idea to cover the shield with heatshrink. Otherwise you have a uninsulated ground floating around in your cavity, ready to silence any hot signal it comes into contact with (the reason why uninsulated braided shield should have been left behind in the 1950s - no other area of electronics uses it).
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https://reverb.com/item/3259725-fender- ... d-anodized
"I just knew I wanted to make a sound that was the complete opposite of a Les Paul, and that’s pretty much a Jaguar." Rowland S. Howard.

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by Tarquin » Sun Dec 05, 2021 1:17 pm

That's amazing, thank you. The picture of the pickguard with the braided wire in place now makes it all clear.

I was all ready to install the pickup the other day, but when I removed the pickguard on my VM and saw that the wiring was (on the face of it...) mismatched, it completely threw me.

Thanks to all, feel confident to tackle it now!

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by MayTheFuzzBeWithYou » Sun Dec 05, 2021 3:00 pm

That is great to hear!
Also thanks to you Timtam to step in with with the technical details! :)

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by Steve Y. » Sat Aug 13, 2022 12:23 pm

Hi all - I'm new here and signed up to ask a specific question (but maybe I'll stick around!)
I recently acquired a J Mascis Jazzmaster and upon plugging it in I noticed that when the 3-way toggle is in the middle position (both pickups selected, Lead/Rhythm switch in Lead position), the tone from the guitar is thin/nasally/brittle. It sounds like a Strat middle pickup that I once mistakenly wired in reverse and was therefor out of phase. I believe the pickups in my JMJM are out of phase with each other.

Now, on the Strat the fix was easy - simply reverse the lead wire connections from the pickup and the problem was solved. In the case of the JMJM, I tried two approaches:
1) Reversed the hot wire and the braid of the bridge pickup where they connect to the 3-way switch and the ground. When I did this I got no signal out of the bridge pickup. So then I put the bridge pickup wires back to where they were originally.

2) Reversed the hot wire and the braid of the neck pickup where they connect to the 'Rhythm' circuit switch. I now get the normal sound from the middle pickup position, but when I put the 3-way toggle into the Neck position it does not change to the neck pickup - it stays in the middle position.

Any ideas for how to maintain the proper middle position tone while getting back the neck position capability?

Thanks in advance for any help!

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by timtam » Sun Aug 14, 2022 3:02 am

Steve Y. wrote:
Sat Aug 13, 2022 12:23 pm
Hi all - I'm new here and signed up to ask a specific question (but maybe I'll stick around!)
I recently acquired a J Mascis Jazzmaster and upon plugging it in I noticed that when the 3-way toggle is in the middle position (both pickups selected, Lead/Rhythm switch in Lead position), the tone from the guitar is thin/nasally/brittle. It sounds like a Strat middle pickup that I once mistakenly wired in reverse and was therefor out of phase. I believe the pickups in my JMJM are out of phase with each other.

Now, on the Strat the fix was easy - simply reverse the lead wire connections from the pickup and the problem was solved. In the case of the JMJM, I tried two approaches:
1) Reversed the hot wire and the braid of the bridge pickup where they connect to the 3-way switch and the ground. When I did this I got no signal out of the bridge pickup. So then I put the bridge pickup wires back to where they were originally.

2) Reversed the hot wire and the braid of the neck pickup where they connect to the 'Rhythm' circuit switch. I now get the normal sound from the middle pickup position, but when I put the 3-way toggle into the Neck position it does not change to the neck pickup - it stays in the middle position.

Any ideas for how to maintain the proper middle position tone while getting back the neck position capability?

Thanks in advance for any help!
Welcome.

I assume both pickups sound OK when selected on their own ? (at least in a wiring configuration that 'works' for each single pickup !).

Is there any reason to believe that the combined pickups would be out of phase, other than sounding thin ? Do you know if the pickups are not stock ? And if not stock, what they are ?

And any sense of any other re-wiring or other mods that might have been done ? With a bare braided shield floating around in a Mascis cavity, I would be looking for places where it might be shorting with another exposed wire. If it turns out that your original problem was not actually out-of-phase pickups in the first place (although that would have been my first thought too), then both your above error scenarios probably now have a bare 'hot' braid floating around in the cavity.

This is the stock circuit for a JM, as in the Mascis.
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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by Steve Y. » Sun Aug 14, 2022 5:20 am

Welcome.

I assume both pickups sound OK when selected on their own ? (at least in a wiring configuration that 'works' for each single pickup !).

Is there any reason to believe that the combined pickups would be out of phase, other than sounding thin ? Do you know if the pickups are not stock ? And if not stock, what they are ?

And any sense of any other re-wiring or other mods that might have been done ? With a bare braided shield floating around in a Mascis cavity, I would be looking for places where it might be shorting with another exposed wire. If it turns out that your original problem was not actually out-of-phase pickups in the first place (although that would have been my first thought too), then both your above error scenarios probably now have a bare 'hot' braid floating around in the cavity.

This is the stock circuit for a JM, as in the Mascis.
Thanks for your reply!
Both pickups sound normal on their own. Before posting here I read a guide for checking pickup phase by using a multimeter and a screwdriver:
* Connect multimeter across output jack tip and ring
* put toggle switch in Bridge position and bring screwdriver to poles, then move it away and note whether the voltage fluctuates positive or negative.
* Move toggle switch to neck position and repeat with neck pickup.
* if one pickup fluctuates positive and the other negative, the pickups are out of phase.

Sure enough, I found that one went positive and the other negative, so I figured that was the smoking gun.

Best I could tell, there were no modifications to the wiring and I believe the pickups are the originals; however, I will go back in today, now armed with the wiring schematic (thank you!) and see what I find.

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by Steve Y. » Mon Aug 15, 2022 3:04 am

Well, the fix was relatively simple. I reversed the lead wires of the bridge pickup where they connect to the 3-way toggle switch and that put the pickups into phase providing a much fuller sound when both pickups are selected. Oddly, before I made any changes the bridge pickup was wired with the outer braid going to ground and inner ‘hot’ wire going to the lug on the switch, but in order to get it in phase with the neck pickup I had to reverse those wires such that effectively now the outer braid is the ‘hot’ lead. This also meant I had to put insulation around the full length of the wire to prevent it from shorting out against the painted cavity of the guitar or any other wiring/components.

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by LeamanCrews » Tue Aug 16, 2022 7:37 pm

Steve Y. wrote:
Mon Aug 15, 2022 3:04 am
Well, the fix was relatively simple. I reversed the lead wires of the bridge pickup where they connect to the 3-way toggle switch and that put the pickups into phase providing a much fuller sound when both pickups are selected. Oddly, before I made any changes the bridge pickup was wired with the outer braid going to ground and inner ‘hot’ wire going to the lug on the switch, but in order to get it in phase with the neck pickup I had to reverse those wires such that effectively now the outer braid is the ‘hot’ lead. This also meant I had to put insulation around the full length of the wire to prevent it from shorting out against the painted cavity of the guitar or any other wiring/components.
Glad you got it sorted out. I wonder, are the pickups on the Mascis JM out of phase by default? I ask because on the J Mascis Tele released earlier this year, they are out of phase by default.

Maybe it's a preference of J's? Playing at the volume levels he usually plays at can bring out the best in out of phase pickups.

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Re: J Mascis Bridge Pickup into VM Jazzmaster - only one wire?

Post by Steve Y. » Fri Aug 26, 2022 5:13 pm

LeamanCrews wrote:
Tue Aug 16, 2022 7:37 pm

Glad you got it sorted out. I wonder, are the pickups on the Mascis JM out of phase by default? I ask because on the J Mascis Tele released earlier this year, they are out of phase by default.

Maybe it's a preference of J's? Playing at the volume levels he usually plays at can bring out the best in out of phase pickups.
It’s possible! I’d be curious for other JMJM owners to chime in here and share their observations. I can say for sure that the out of phase thing is not my cup of tea, so I’m glad it ended up being an easy fix.

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