Pablos RC-4

[pablopepper]

Ended up going with white again. Should be here pretty soon.

Wiring question: So, after wiring this thing up I've noticed a couple of oddities. The centre position of the switch (both pickups) is noticeably quieter than either of the single pickups by themselves and when the volume of either is dropped (still in the centre position), even very slightly, it kills the signal from that pickup all together. Only get sound from both pickups when the volumes are equal. There is also a loud clack when using the switch.

Does this sound like a busted switch or have I stuffed something up (more likely)?

[wokkaboy]

hey Pablo, thats a strange problem, so does the volume pot work ok when either the bridge only or neck only pup are selected ?
sounds like its not your pots but most likely is your switch if the soldered connections are ok and its earthed to the bridge ok. Have you got the hot tip on the output jack the correct way ?

[WeirdBits]

I have a feeling it could potentially be a combination of things. Your pickups are a Fender bridge and Gretsch neck, right? It's possible there could be a phase issue when they're combined in the middle position which could impact the output level, or it could just be faulty contacts in the switch, or both. But I think there may be something more as well. Are you using the PBG RC4 wiring diagram, and are your pots 500K A or B? Maybe post some pics of your wiring setup?

[pablopepper]

I am using the same layout as that diagram and yes, Fender in the bridge and Gretch in the neck. Pots are all Bourns 500k audio taper. I was pretty thorough with my soldering and I've gone over it since and everything seems good. I hadn't even considered the phase issue, how would I check that?

Here's the only pic of the wiring I've got


Thanks Scott and Wokka.

[wokkaboy]

your wiring appears to be ok Pablo, think Weirdy maybe onto something. will be a bugger if you have to match the pups !

[WeirdBits]

Buy some more colours! Easiest way to test the phase issue (assuming at least one of the pups has separate positive, negative and ground/shield) is just reverse the positive and negative connections on that pup then give it a listen in the middle position. If you have a multimeter you can do some specific tests.

Edit: Just did a quick search, looks like Fender has red as hot and green as ground, while Gretsch probably has white as hot and black as ground... I think.

The layout is LP style with the pickups on the outer lug of the volume pot and the switch on the middle lug, so if you want Jazz bass style independent volumes you may want to swap the pickup (and tone link) to the middle lug and the switch on the outer lug. Not sure if that would help with the volume sensitivity issue.

[Nickosaurus]

I'd say phasing or the switch's connection/function would be the issue/s here. It's happened to me before in the past mixing pups.

[pablopepper]

Thanks heaps for the help guys, I really appreciate it.

It seems phasing is the best explanation for the weirdness. So after reading up a bit and watching that excellent video (thank you Scott), I have three ideas, all of which are probably going to demonstrate exactly how little I still understand. Only dealing with the Fender pickup as it's the easier of the two to move/modify. I'll start with the simplest.

1. Flip the pickup 180 degrees. To me this sounds too simple, but in my mind it does swap the magnets to where they need to go. Might not have enough slack on the wires.

2. Reverse the hot and ground wire. I keep coming across this solution, but invariably paired with folk who say it won't work.

3. Reverse the wiring on the pickup itself. Currently it's wired up like this

If I swapped it around to this configuration

will that do what I need it to?

Opinions? Will any of these work?

Thanks again, once again this forum proving invaluable.

[wokkaboy]

hey Pablo, probably best wait for the guru Weirdy to answer that one.
In the meantime I'd try option 1 and flip it 180 degrees, doesn't have to be screwed down (hopefully the screw mount holes should line up). You may have to lengthen the wire but to me this seems the simplest possible solution without mucking around with the pickup wiring configuration

[WeirdBits]

Flipping it may *slightly* change the tone of that pickup by itself, but it won't affect the phasing in relation to the other pickup. That's controlled by the configuration within the pickup itself, regardless of its physical orientation. Options 2 and 3 are essentially the same, it's just that option 3 is doing the reversing within the pickup itself.

What wires do you have coming out of each pickup, are they both two conductor like in the image above? If so, just reverse your hot and ground connections for the bridge pup and give that a try. If that does correct the phase issue, if that's what this is, the sound should be noticeably fatter in the middle position.