My P-Rails Build

[RadsRock]

Hello all -- what an awesome community there seems to be here!

So, I am trying to decide how to wire my HxH project guitar with 2 P-rails. This is my first full build, and my wiring/electronics knowledge is about pre-K level. I have read lots of threads on P-rails wiring and considered lots of options in how I might want to set up mine. Now, the body is from Warmoth, coming with no control holes/slots drilled, so all possibilities are open. I have come up with an approach that I don't think I've seen discussed, and wonder what y'all expert folk think about this.

The idea would be to use concentric pots in a sort of a spin-a-split approach. For each pick-up there's one concentric pot pair, 1 pot controlling the P-90 and 1 controlling the rail:

Inner pot turned all the way up, outer pot turned all the way down: P-90
Inner down, outer up: Rail
Both up: Humbucking
Both down: Pick-up is off (so no bridge/neck selector switch is needed).
​

The hot ouptut from each pot would then go to a mini-toggle, to allow series/parallel switching.

Is there a reason this doesn't work? Do you see pros/cons to the approach?

I am thinking it would be clean & tidy, and easy control to a huge tonal spectrum. One downside is it would be a bit slower to switch from bridge to neck on the fly, but I think I could live with that. On the plus side, it would provide a couple of things I "think" I want, but I'm frankly not sure the utility of:

1) The single coils on each P-rail are fully selectable independent of the other pick-up (eg, could have neck on rail and bridge on P-90). But is that really worthwhile? Since the coils are designed to be hum-cancelling with the matched coil on the other pick-up, would it get noisy to have the two non-matched coils on?
2) Serial/Parallel switching. Of course if that isn't wired in as a switchable option, I would want the humbuckers in series (so I don't think the concentric pots approach would work without the mini-toggle -- right?). But, is the series/parallel tone selection worth having at all?​

Now, one more key question while I'm at it. Here is the body... Pao Ferro top over Black Korina (IMO, going to be one beautiful axe!) So.... P-Rails in Black or Cream?

 

[ParameterMan]

Re: My P-Rails Build

You're going to have to link to the image- it's a fancy URL that doesn't end in .JPG so the BBcode parser won't like the taste of it.

 

[RadsRock]

Re: My P-Rails Build

I moved it over to picasa... that did the trick.

BTW, I think gold for the hardware, eh?

 

[ParameterMan]

Re: My P-Rails Build

With that wood? Yes. I'm not normally for gold, but I think it would look classy here.

 

[RadsRock]

Re: My P-Rails Build

Hmmm... too whacked of an idea? Or just too wordy in the OP? :1:

 

[ParameterMan]

Re: My P-Rails Build

I've messed about with making up a diagram that does everything you want, but I'm having a hard time getting things nailed down in my head. I think it may be possible, but here's some thoughts:

Pickup switching is too handy to lose, as is a master volume. I think this setup sounds awful fiddly and not terribly handy in a live situation. I would personally lean towards using two center detented ganged pots with a master volume and three way switch. The center of each pot would be humbucker mode, with one coil at each end. That way you could spin-a-split in either direction. Also, using both split knobs in equal amounts for a volume control will surely mess with the sound of the humbucker.

The series/parallel switch could be a pain, as spin-a-split works with the series connection. You have both coils in series with a pot in parallel with each one, allowing it to be variably bypassed. The easiest switching to parallel would turn both pots into master volume controls. What you want is both coils in parallel with a pot in series with each, allowing individual control. That's possible, except it would invert the volume settings. The coils would flip from fully bypassed to full-on and vice-versa. So what needs to be done, especially if you're using the ganged pots is to switch the pots around and use the opposite ends of the track for series and parallel. It surely can be done using a 4PDT for each pickup, I just need to figure out how. Or Artie could show up. Or you could drop that mode, but it's a cool challenge.

 

[RadsRock]

Re: My P-Rails Build

Actually I would plan on having a master volume (and single tone) with this plan. Sorry I left that out.

I would personally lean towards using two center detented ganged pots

By this, do you mean what is sometimes called a 'blend pot'? I did consider that, but thought that would leave me stuck with the coils in parallel.