Help: Wiring a Mike Richardson variation

[ring0]

Hello all. Long time reader, first time poster.

I'm having a no sound issue that I am unable to troubleshoot. I have some presumptions as to where I've buggered up the wiring on this guitar but I'd like an expert's opinion before I recommence surgery.

About me: I have soldering and electronics experience. I researched for five weeks before committing to this project - Figured I'd actually do something with all that I'd learned.

What I'm trying to do:

My guitar is a Yamaha Pacifica 112 CPJ - One humbucker, two singles, one volume pot, one tone pot, mono output jack.

After having it for many years I wanted to improve my sound options, as well as the guitar itself. I did some physical work on the guitar (aligning neck, paint touch-up, general maintenance) before getting to the bulk of my project: the electronics.

The electronics that came as stock weren't of a great quality. Took 'em all out. Wires weren't soldered cleanly and long stretches of braid criss-crossed around the cavity. No treble bleed circuit. Lastly the guitar had the standard small piece of foil on the pickguard's corner as shielding.

Replaced with better quality parts:

* Volume: CTS 500k Audio Push/Pull (DPDT) Pot.
- Treble bleed circuit: .001uF Orange Drop Cap in parallel with a 130k resistor.
* Tone: Burns 500k Audio no-load Pot.
- Tone Cap: CDE Film .022uF Cap.
* Switch: StewMac Super Switch (4-pole, 5-throw) .
* Output Jack: Switchcraft 1/4" Stereo Jack.

My overall scheme involves applying quality shielding & grounding (as per the Shielding a Strat instructions), modify the humbucker from two-conductor to four-conductor, followed by unmounting the stock electronics and putting in the new ones. I then want to do the Mike Richardson wiring and rock 'n' roll my guitar.

What I did:

It was smooth sailing until the last part. First I installed the shielding, along with the grounding ring in the cavity + the 400 DC .33 uF cap and checked that everything worked before removing the old parts.

Humbucker's change went without a hitch. Potted all my pups at this point.

All the new parts checked out and were within 1% of their specified specs. Put 'em in. Left the new switch out and did a trial with the stock wiring. No problems.

Swapped the new switch in and carried out the wiring. No sound comes out and the multimeter is indicating a short between hot & negative at the output jack.

I'm certain I have no dud components or cold solder joints, but I can't spot where I messed up the wiring. I suspect three locations for the issue:

- I had to mickey mouse the initial schematic as I have one tone pot. I found a thread by another gentleman who had a similar issue and used that as my basis. My electrical diagram is below.

- Tone pot has been wired incorrectly.

- Volume pot has been wired incorrectly.



For reference here's the original:



In my guitar the B- going to ground includes the conductors for south coil start and bare shielding. The north coil and south coil finish are spliced together as in a standard two-conductor. North coil start is B+ in the circuit.

Any thoughts on what I did wrong? Any improvements are also welcome.

Some pictures of the spaghetti bowl.





Thanks in advance,
Cesar

[pete12345]

I've spotted one error with your tone pot wiring- you don't need the ground connection. The tone pot should be wired 'around' the neck pickup only, as you've done with the middle and left terminals. The right terminal should be left disconnected. As it is currently, turning the tone pot fully up will short the jack.

As an aside, the disconnected terminal on the N- pole of the switch will cause the neck pickup to hang from hot when M+B is selected. You can avoid the noise this creates by instead wiring that terminal to the N+ connection. This shorts the neck pickup when it's not being used.

[ring0]

As such:

[ring0]

I've sat down with a cup of tea or three and had a good think. I still can't figure out where I went wrong - The issue isn't apparent to me from the diagram.

I did a quick sanity check and re-did all the solder connections (everything seemed to be fine, but just in case) and took the opportunity to test the pickups individually to the volume pot and out the jack. All three checked out on the multimeter and through the amplifier. Put it all back the way it's shown on the above picture and it's back to no sound.

[newey]

ring0-

I haven't had a chance to check your diagram, but it is unlikely that a no output condition would result based on a diagram error, especially since you've been through it already. More likely is that something is shorting the output by touching where it shouldn't.

Start at the output jack. Check continuity to hot and ground with the pickguard off the guitar. Work backwards through the circuit.

Did you perhaps shield the jack cavity?

Are either of the pots' lugs facing outward, towards the side of the cavity? If so, rotate 'em inward.

Check for output from the 5-way switch (via "A").

[ring0]

I followed your suggestions and was able to make some progress. I now get a hum when plugged into the amp though no signal from the pickups - The volume pot reads 0 on the multimeter, ~150k ohms when approximately halfway (hum intensifies), then back to 0.

I'll take a closer look after work.

And yes the pots are facing inside. The ground ring is squeezed in-between the volume pot and the switch. My control cavity is roomy, though the super switch is quite large - There's no shielding on the jack cavity.