Push/Pull for Series/Parallel Issues

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adamrobertt
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Push/Pull for Series/Parallel Issues

Post by adamrobertt » Fri Jul 16, 2021 1:56 pm

Hey guys. I'm wiring a J style bass with master volume, pan, and passive tone. The master volume is a push/pull switch that I'm trying to wire for series/parallel.

I used this diagram:
Image

Everything is wired correctly but the circuit does not work as intended. I get no output in any position except that the bridge pickup works when I pull up on the push/pull. In all other positions I get no sound at all. Anyone have any ideas on where I went wrong? The pickups both tested at around 9k, so I know they work fine. Any help would be appreciated.

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timtam
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Re: Push/Pull for Series/Parallel Issues

Post by timtam » Fri Jul 16, 2021 10:23 pm

Complex wiring diagrams are hard to troubleshoot. Schematics are easier. And of course we can only assume that you wired it as the diagram shows. ;)

A useful strategy when some switch positions don't do what they are supposed to do is to print out as many versions of the diagram as there are switch positions. On each printout, use a highlight pen to highlight the signal lines that are in-circuit for one switch position. That should show if there is a missing connection to make a complete, functional circuit in any switch position(s). If it doesn't, and each printout shows the circuit doing exactly what it is supposed to, then chances are that you missed something when wiring it up. So follow the highlighted connections on each printout in your actual wiring, one at a time.

When you get no sound at all from intact pickups, that often means an open circuit in the wiring - that is, the coil hot or coil ground is not connected all the way through - or a short of the hot to ground somewhere (eg to cavity shielding ?).

Also, if using the CTS push-pull pots that have the strange pin layout, check that you have the correct pins connected, and no shorts between connections to the close pins (I always use heatshrink to cover all bare wire). In fact check with your multimeter that the switch contacts are being connected as you assume, in case the switch is faulty.
"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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jorri
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Re: Push/Pull for Series/Parallel Issues

Post by jorri » Sat Jul 17, 2021 5:10 am

-i cant spot anything, but the problem suggests an issue with the neck signal for sure so at least thats a place to start debugging. (See below, series requires both pickups to work or none will)

-do you realise the pan will act simply like a volume control when in series? The bridge side is disengaged. This is common, to have series only work when the last pickup's selection is on as it now all goes thru that pickup, whilst the first pickup is taken off its own switch entirely.. Unless you add more switch poles to bypass the switch or something.

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adamrobertt
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Re: Push/Pull for Series/Parallel Issues

Post by adamrobertt » Sat Jul 17, 2021 5:16 am

timtam wrote:
Fri Jul 16, 2021 10:23 pm
Complex wiring diagrams are hard to troubleshoot. Schematics are easier. And of course we can only assume that you wired it as the diagram shows. ;)

A useful strategy when some switch positions don't do what they are supposed to do is to print out as many versions of the diagram as there are switch positions. On each printout, use a highlight pen to highlight the signal lines that are in-circuit for one switch position. That should show if there is a missing connection to make a complete, functional circuit in any switch position(s). If it doesn't, and each printout shows the circuit doing exactly what it is supposed to, then chances are that you missed something when wiring it up. So follow the highlighted connections on each printout in your actual wiring, one at a time.

When you get no sound at all from intact pickups, that often means an open circuit in the wiring - that is, the coil hot or coil ground is not connected all the way through - or a short of the hot to ground somewhere (eg to cavity shielding ?).

Also, if using the CTS push-pull pots that have the strange pin layout, check that you have the correct pins connected, and no shorts between connections to the close pins (I always use heatshrink to cover all bare wire). In fact check with your multimeter that the switch contacts are being connected as you assume, in case the switch is faulty.
I went over the connections like 10 times and I'm pretty sure it's all correct - but then again by the end I was burned out. I have continuity at all points on the circuit as tested with a multimeter but I didn't actually check the switch, I'll do that first thing.
jorri wrote:
Sat Jul 17, 2021 5:10 am
-i cant spot anything, but the problem suggests an issue with the neck signal for sure so at least thats a place to start debugging. (See below, series requires both pickups to work or none will)

-do you realise the pan will act simply like a volume control when in series? The bridge side is disengaged. This is common, to have series only work when the last pickup's selection is on as it now all goes thru that pickup, whilst the first pickup is taken off its own switch entirely.. Unless you add more switch poles to bypass the switch or something.
Yes I did realize this, I actually had previously tried a different scheme that bypassed the pan pot in series mode to get around this problem, but oddly enough when I wired it all up I had the exact same problem that I'm having now. It really seems like the neck pickup should be bad, but it tests fine with a multimeter. I'm pretty stumped.

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jorri
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Re: Push/Pull for Series/Parallel Issues

Post by jorri » Sat Jul 17, 2021 5:34 am

Hmmm, looking at the diagram is ok, hope i havent missed anything...

First thing i would check every connection the neck goes through with a multimeter in sequence- place one pin on the + of the pickup and follow through to output and you should find it (with pots/switches open allowing full path of the pickup); and if not, try its -ve same process.
Bad component or solder, is probably most likely.

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