4-Pos/3-Pole Rotary Switch for two pickup wiring

[Immo]

I'm looking to ditch the Jazz-style wiring on my P+P bass, because it doesn't work the way it should, rolling down one volume essentially makes its pickup inaudible anyway. I want to swap one pot to a 4-position rotary switch that will enable switching between: Neck PU only, both PUs in Parallel, both PUs in Series, Bridge pickup only.

I searched online and can't seem to find a wiring diagram nor a thread on forum/Reddit/etc. that understands that mission, and I could've sworn that before the search engines suffered a major episode of enpoopification, the diagram WAS there.

Anyway, I made a crude diagram myself and just want to make sure it's legit. My ADHD brain sometimes just won't cooperate with such focused tasks. Any help and feedback would be appreciated.

  

 

Edited September 17 by Immo
Cleaned the pic

[Mediocre Polymath]

I've done exactly this on a few guitars. I'm not near my computer, but I have diagrams somewhere. I'll have a look in the morning.

[Immo]

2 minutes ago, Mediocre Polymath said:

I've done exactly this on a few guitars. I'm not near my computer, but I have diagrams somewhere. I'll have a look in the morning.

This would be much appreciated.

[Mediocre Polymath]

Aha. Found it. I had a copy buried in my photos folder for some reason.

[Immo]

1 hour ago, Mediocre Polymath said:

Aha. Found it. I had a copy buried in my photos folder for some reason.

Looks the same, just w/ swapped pickups and one Hot output being soldered to output terminals instead of the inner pole (A). Is there any practical difference?

[Mediocre Polymath]

7 hours ago, Immo said:

Looks the same, just w/ swapped pickups and one Hot output being soldered to output terminals instead of the inner pole (A). Is there any practical difference?

I don't think so, no. I've not done any serious electrics stuff in a while, so I can't make sense of either diagram right now (despite drawing one of them myself). I just know that this works and that I wrote it down at some point. 

 

One bit of advice I would add is that the sealed plastic rotary switches that most vendors sell aren't very robust. I've had two fail now – not catastrophically, but annoyingly (having to wiggle the switch to get position 4 to engage, that sort of thing). I don't know if you can get heavier duty three pole switches anymore though.

[Hellzero]

Here are two diagrams from Cadfaels with the serial place on the switch better positioned (to avoid huge differences in output).

 

The second one uses Leds, which can be interesting too.

 

Click 3 times on the image to have it in full definition.

 

 

 

 

[Mediocre Polymath]

4 minutes ago, Hellzero said:

Here are two diagrams from Cadfaels with the serial place on the switch better positioned (to avoid huge differences in output).

 

The second one uses Leds, which can be interesting too.

 

Click 3 times on the image to have it in full definition.

 

 

 

 

Interesting. I had considered wiring a variable resistor into the series position, so I could adjust the output. I decided that a) I quite liked the "onboard boost" effect, and b) I couldn't be arsed.

 

This is a recurring problem with me and instrument wiring. Generally by the time I get to the wiring stage on one of my instruments, I've put in 40-60 hours of work over several months and I just want the damn thing to play. Finesse tends to go out the window.

[MartinB]

2 hours ago, Hellzero said:

with the serial place on the switch better positioned (to avoid huge differences in output).

You just mean moving the loudest (serial) position to one end of the switch, right? So that when flicking between settings, you don't have to go "across" the loudest one.

[Hellzero]

Exactly @MartinB. 😉

[Immo]

14 hours ago, Mediocre Polymath said:

One bit of advice I would add is that the sealed plastic rotary switches that most vendors sell aren't very robust. I've had two fail now – not catastrophically, but annoyingly (having to wiggle the switch to get position 4 to engage, that sort of thing). I don't know if you can get heavier duty three pole switches anymore though.

I found open one made by Alpha, specifically for guitar and effects that should do the trick.

[Immo]

13 hours ago, Hellzero said:

(...) the serial place on the switch better positioned (to avoid huge differences in output).

That's actually very good call. So I edited my design:

 

Should do the trick?

[Immo]

Forgot to post an update: I wired it the way it's been shown in the above pic and it worked bed because I forgot about swapping hot and ground wires from one of the pickups and it was comb-filtering and sounded thin. After fixing that, it's done. Honestly, the difference between both PUs in series and in parallel is negligible despite output DCR being doubled in series. The volume boost is barely noticeable, but the tone has a bit more oomph. Sound thicker and darker, and seems to better open envelope filters and make fuzz pedals more angry. In other words, the series setting seems to be more influenced by the middle pickup while the parallel setting takes more from the bridge pickup.

Overall, I'm satisfied with this modification and like it more than the Jazz Bass style wiring I had previously since it was inefficient. The middle, bigger chickenhead knob is the rotary selector.