Wierd idea, but had to ask.

[TonyFlyingSquirrel]

I use treble bleed mod on my volume pots, but the thought occurred to me.

What if I want to add one to the neck pickup, and switch it in/out?

Would there be any perceived difference? Would it be the same as High Pass Filter?

Anyone ever done this? Got a wire diagram?

 

[Prometheus]

That's not exactly going to be straightforward. Because the usual implementation of a treble bleed is of a high-pass filter acting as a shunt across the two non-ground lugs of the volume pot. So it's downstream of your pickup selector, and acts on the combined signal of whichever pups the selector has activated.

In order to have it act exclusively (switch-enabled or not), it'd need additional wiring that would be dependent upon the selector being in the neck position. So no, not easy, so far as I can see. I'll think on it some, and hopefully someone else will offer up an inspired solution

 

[Prometheus]

Okay, I have an idea. Couple things though. First, it will probably take some sort of "super" selector switch. And a dual-gang pot where your volume is now. And if you really want to toggle it in/out, then that will be a push-pull pot, or you'll need to install a new separate switch. If you want me to take a run at this for you, I'll need a schematic of your entire setup as it is now

 

[TonyFlyingSquirrel]

Okay, I have an idea. Couple things though. First, it will probably take some sort of "super" selector switch. And a dual-gang pot where your volume is now. And if you really want to toggle it in/out, then that will be a push-pull pot, or you'll need to install a new separate switch. If you want me to take a run at this for you, I'll need a schematic of your entire setup as it is now

Simple 2 p/u with one volume, no tone.  Like some of the Charvel's out now.
I don't mind wiring up the switch as a stand alone 2 pos switch like the ones Warmoth sells.  Drilling a hole into a strat pickguard is easy peasy.

 

[Prometheus]

OK, so you're going to need to replace your volume pot with a dual-gang pot. Good idea here to test a few (or swap some wafers around) because it'd be nice if their resistances matched. And as mentioned, a toggle switch, which can be a real simple SPST. Last thing is a new pickup selector. You'll need one with at least three poles (3P3T(. I found the Schaller Megaswitch T on their site, and a wiring diagram that leads me to believe that it is a 4P3T. That particular one is a blade-type, and I'd forgotten to ask if that was your flavor or what. But such is definitely obtainable in a rotary, and maybe (?) also in a toggle.

The selector in the diagram is in the green box. The toggle switch for the neck-only treble bleed is in the red box, and the treble bleed resistor and cap are in the blue box. I just arbitrarily chose the treble bleed as a series config, but you could also do it in parallel - whichever floats your boat. Incidentally, with all treble bleeds, the resistor and cap sizes must be carefully chosen to match the volume pot's resistance and the characteristics of the pickups. That last part is usually a pain, as it changes with selector position. But here it's only ever hooked up to the neck pup, so you can choose optimal component values for that.

The top pole of the selector switch is the trick here. It routes the neck pickup to the top volume pot (and the treble bleed) only when the selector is in position 3 (neck). In positions 1 and 2, it routes the neck signal to the second pole, which in position 2 ends up combining with the bridge, and in position 1 it is unconnected. All good. Pole 3 is dedicated to the bridge pup's signal in the normal way. And pole 4 is unused (I guess I could have just left it out).

So in position 3, you get neck. Check. And if the toggle switch is closed, you have neck-only treble bleed. Check. And if the toggle switch is open, you have neck-only no treble bleed. Check. All this runs through the top volume. In positions 1 and 2, the output is run through the bottom volume. But since that's a dual-gang pot, and both gangs are the same value, you're all good.

OK, anybody .... what have I messed up here? (there's always something)

 

[Prometheus]

BTW, I also ran across some 4-position blade-type selector switches. Maybe one of those could be used to come up with an alternative arrangement, where position 3 would be neck "regular", and position 4 would be neck+bleed.

 

[Prometheus]

Looking further into that 4-position switch, I found the Telecaster 4-way switch. I thought that'd be a good idea, so I did up a layout with that. The 4-way does away with the extra toggle, because position 3 is the regular neck-only, and position 4 is the neck+bleed. Looked good.

And then I saw the problem. Both volume pots always have a path to ground. Looking at the new diagram, take for example position 4. This is supposed to be neck+bleed. The neck pickup's signal is the only one to make it to output, via the upper volume pot and the treble bleed. As the volume knob is turned, some signal goes through upper pot's resistance and out to ground via lug 1. The rest of the signal goes to output. Except that signal can also go to ground via the still-connected center lug of the lower volume pot, through that pot's resistance and its lug 1. So if the volume is halfway, instead of half volume, you'll get less, because of the parallel ground route. The the first layout has same flaw. Drat.

So, not so good as I'd hoped. One way around it would be to increase the volume pot's resistance values. That could compensate for mid-rotation volume loss. But it would give the maxed knob position a bit harsher sound (as higher-value volume pots always do). And it would make for an altered taper, due to the parallel resistance. But linear taper pots could at least partially offset that effect.

A better solution would be to be able to open the lug2 connection on whichever pot is not in use. That requires another position-dependent switch. Going back to the first layout, maybe the unused pole of the selector switch could be tasked with this. I'll think on it some more.

And in the meantime, welcome other suggestions.

 

[Prometheus]

All right, third time's a charm, right? Back to the multi-pole selector switch. Again, all that's needed is 3P3T, but a 4P3T with an unused pole is fine. No more dual-gang volume. Two poles do the regular pup switching. The third pole makes or breaks the treble bleed, and it's connected only in position 3. The SPDT toggle switch comes back in.

All normal pup selection in all positions. Position 3 alone has treble bleed, and only when the toggle enables it.

Whew.

Sorry for all the false alarms.

 

[TonyFlyingSquirrel]

All right, third time's a charm, right? Back to the multi-pole selector switch. Again, all that's needed is 3P3T, but a 4P3T with an unused pole is fine. No more dual-gang volume. Two poles do the regular pup switching. The third pole makes or breaks the treble bleed, and it's connected only in position 3. The SPDT toggle switch comes back in.

All normal pup selection in all positions. Position 3 alone has treble bleed, and only when the toggle enables it.

Whew.

Sorry for all the false alarms.

I think I "get it", but I'm not sure if the switch in this diagram is a toggle or a blade.

Since the SPDT is back in play, that also opens up the option of using a push/pull pot to minimize real estate.

 

[Prometheus]

The selector switch can be any type you want. It's physical makeup is immaterial to the wiring, so you could use toggle, rotary, or blade. The only thing is for you to find the one you want. I moved the one pole away from the others in the layout, just to avoid long lines, but of course all three poles are still on the physical switch, and you'd have to run the wires to it. No biggie.

A 3P3T or 4P3T blade-type switch as typically used in guitars could be hard to get. I mentioned that the Schaller Megaswitch T looks (from the wiring diagram on their site) as though it fits the bill. And apparently the blade switch used in the Ibanez JBM is also suitable, but you'd have to confirm that yourself as I didn't dig too deeply.

If you want a toggle or a rotary, well, there's probably a gajillion of 'em available from the usual suppliers, Mouser, Digitech, etc.. As well as maybe some from guitar parts suppliers. Google up.

I'd asked about the push-pull earlier, and you said that you didn't mind a separate toggle. But again, it's just a matter of taste. It'd be easy to get a toggle from just about anywhere, and most guitar parts suppliers will have a push-pull pot with the correct resistance and taper for use as a volume control. Just use any SPDT part of that. You could even use a Fender S-1 switch (some people like 'em, others don't), and use just one of it's poles.

 

[TonyFlyingSquirrel]

This is totally cool, thanks for your efforts on this.
My brain works at warp speed, so often that I think out loud more than I should.
Cool thing is, with a strat pickguard, you could come up with all sorts of options that aren't invasive to the guitar itself, things you may never want to do to a rear routed guitar.
Thanks again!

 

[TonyFlyingSquirrel]

Found some more info, may have to get another pickguard to load this on & drill for the switches.
http://www.premierguitar.com/articles/print/21112-three-must-try-guitar-wiring-mods

It's the Treble Cut, and Bass Cut mods.