Rotary switch and Strangle circuit in JM

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bigugly
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Rotary switch and Strangle circuit in JM

Post by bigugly » Mon Oct 04, 2021 11:08 am

Finally making the switch from my Jaguar to a Jazzmaster. I love the Jag, but my fingers are just too big for that shorter scale.

The JM is a lot more comfortable and easier to play, but I find myself missing some of the aspects of the Jaguar. So I'm looking to dig into it and make some modifications...

Right off the bat, the pickup selector toggle has got to go. I'm also missing the Jaguar Strangle circuit (yes, I know, different pickups, but I still want to try it).

Anyone out there know if it would be possible to wire up a rotary switch that would include the strangle circuit on one of the positions? I've seen some diagrams that show a 4 position rotary with neck/parallel/series/bridge configuration. I'm not necessarily interested in parallel/series and it would be cool if one of those positions could be bridge with Strangle circuit.

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Re: Rotary switch and Strangle circuit in JM

Post by bigugly » Wed Oct 20, 2021 8:12 am

One step closer to starting work on getting my Jazzmaster more Jaguar-like.

Curtis Novak came through with one of these for the bridge:
Image

Just waiting on scrounging up a strangle circuit capacitor and I'll be digging in. Still don't have a final wiring diagram to work off of, but it shouldn't be too hard to figure out. If anybody's got a suggestion, I'd totally appreciate it...

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Re: Rotary switch and Strangle circuit in JM

Post by bigugly » Thu Jan 13, 2022 9:09 am

Long post, but it's been an adventure, so I thought I'd document it.

Wiring this project together took a lot more head scratching than I anticipated. Not complicated in the grand scheme of things, but definitely the most complicated (and frustrating) guitar wiring project I've done in the last 30 years.

This is what I was able to come up with:
Image

I've never really worked with rotary switches before, so it definitely was a learning experience.

On my first wiring attempt, I made the assumption that the layout of the rotary switches was like this:
Image

Went through with all the soldering, plugged the guitar in and... nothing.

Turns out that the layout of the switches is actually this:
Image

Wired the rotary switches back up in the correct orientation and plugged the guitar in... still nothing :fp:

Triple checked my circuit design and quadruple checked my soldering job. Aha! I had accidentally reversed two wires. Soldered them into their proper lugs and plugged in. Got sound, but only out of the Bridge Pickup.

I grabbed the multimeter and determined that the Neck pickup was not giving any reading. Damn. This JM has shielding plates in the pickup cavities. They fit pretty tight and the neck one got stuck when I was removing the neck pickup and gave the ground lead a good yank, most likely damaging it. I tried to reflow solder on the ground lead, but no dice. Luckily I had a spare Pure Vintage 65 to pop in. With that new pickup in place, plugged in and success!

Everything works as intended.
The Rhythm circuit rotary functions the same as the original 2 way switch, but is wired to repeat (because it is a 4 position switch), instead of killing the circuit on the extra positions. So: A) On, B) On, C) Off, D) Off

The Pickup Selector positions are: A) Bridge (with Strangle circuit), B) Bridge, C) Bridge/Neck, D) Neck

Definitely happy with the results. Eventually, I will need to go back in to fix two problems. The first is that the Pickup Selector rotary does not quite fit in the existing cavity. If you look in the pictures, you can see where the knob is actually "leaning" a little, due to the switch being pushed up against the wall of the control cavity. No biggie, a tiny bit of sanding with the dremel should fix this.

The second problem is a little more daunting. The wiring between the Rhythm rotary and the Pickup Selector rotary is too short! I don't know how this happened as I don't recall dramatically shortening any of the existing leads. The wiring should route through extra space at the bottom of the neck cavity. Instead, I had to run them underneath the pickup support foam. Eventually, I'll need to go back in and rewire with longer leads.

Thanks to Curtis Novak for the custom Jaguar JM pickup and to Shadoweclipse13 for encouragement along the way!
Last edited by bigugly on Thu Jan 13, 2022 9:27 am, edited 1 time in total.

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Re: Rotary switch and Strangle circuit in JM

Post by bigugly » Thu Jan 13, 2022 9:18 am

Pics:
Image
Image
Image
Image

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Re: Rotary switch and Strangle circuit in JM

Post by Shadoweclipse13 » Thu Jan 13, 2022 10:00 am

I definitely didn't really help much, but happy the project is coming together so nicely. That is a gorgeous guitar!! Did your neck pickup wire get sorted out? (Or was that someone else?)
Pickup Switching Mad Scientist
http://www.offsetguitars.com/forums/viewtopic.php?f=8&t=104282&p=1438384#p1438384

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Re: Rotary switch and Strangle circuit in JM

Post by bigugly » Thu Jan 13, 2022 10:25 am

Shadoweclipse13 wrote:
Thu Jan 13, 2022 10:00 am
I definitely didn't really help much, but happy the project is coming together so nicely. That is a gorgeous guitar!! Did your neck pickup wire get sorted out? (Or was that someone else?)
Nah, had to replace it. I'm not sure where the damage is on it, everything "Looks" ok, but I don't even get a meter reading even at the the lead solder points on the pickup.

I'm not terribly impressed with construction on those Fender Pure Vintage JM's. Same thing happened with the bridge pickup on this guitar. The shield got stuck coming out of the cavity and pulled the ground lead out of it's solder point. I was being gentle when removing the pickups and barely tugged on the lead. Luckily I was able to repair that pickup. No dice on the Neck pickup though.

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Re: Rotary switch and Strangle circuit in JM

Post by Shadoweclipse13 » Thu Jan 13, 2022 11:43 am

That's a shame! I'm glad your switching schematic ended up working!

I'd said that that jumper wire wouldn't work, and then I was looking at it and realized that I was wrong. I was thinking about that jumper if you'd attached the pickup lead to the switchable terminals, instead of the common. Total facepalm moment. It's been a long few weeks, haha.
Pickup Switching Mad Scientist
http://www.offsetguitars.com/forums/viewtopic.php?f=8&t=104282&p=1438384#p1438384

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