2 Pickups with their own Vol & Tone pots, then a Master Vol

[jlaff]

Greetings.

I have a question.  I'm working on a new build.  A brief description is:

Neck Humbucker
Bridge Humbucker

3-Way Switch

Each pickup goes to a concentric (500k/500k) set of pots.  In other words, Each pickup has its own dedicated volume and tone pots.

Master volume pot (500k) to control overall volume.

I'm worried about high end loss.  Should I use treble bleeds on all 3 volume pots (Neck, Bridge, Master)?  If so, what do you recommend?  I was planning on using the parallel resistor/capacitor style (Seymour Duncan style) but maybe I should only use that on the Master Volume and just use a capacitor on the individual pickup volume pots.

Thoughts?  Or maybe this whole thing is a bad idea.

Thanks for your help.

[newey]

jlaff-

Hello and Welcome to G-Nutz2!

I would consider closely how much you really want/need that master volume pot.

When either the neck or bridge pickup is selected by itself, you'll have three pot elements (V, T and Master) loading the circuit which can dull your tone, but maybe not something you'd notice. Flip to the center position on your three-way, though, and with both pickups active, you'll have 5 pots in the circuit. That's quite a lot. I'm guessing that will knock your high end off noticeably.

You might want to look at JohnH's GuitarFreq. You could at least get a graphical look at the changes that would be entailed with the pot set-up you have outlined. Not the same as hearing it, naturally, but just to give an idea.

Treble bleeds are fine, but they won't solve the issue I'm thinking here.

If you really want a master volume, just wire the guitar like a regular ol' Les Paul with individual V and T pots. Then get an active volume pedal with a buffer- no tone loss, and will operate truly independently of the guitar's onboard controls. But that's just my 2¢ worth . . .

[jlaff]

Thanks a lot for the response. 

I'm going to go ahead and add the master volume.  I've got a 1000K pot sitting around and I'll try that vs a 500k pot for the master volume.  If it doesn't work out, then I'll go back to the drawing board. 

I could technically achieve what I'm looking for here with 4 pots instead of five if I go with individual tone pots for each pickup, a volume fader and a master volume instead of the original plan.  If all else fails, I can try the fader option and still get the results that I want.

I considered doing exactly what you recommended (Les Paul wiring with active volume pedal) and I may still go with that option is plans A and B fall through.

Thanks again.

  

[JohnH]

I think you've hit on the issues to consider. Adding an extra volume control stage does take another slight edge off the tone. Very high pot values help at max volume but add more issues as you turn down. Treble bleed helps a bit.

My friend has a Gretsch, which have a similar arrangement. Here's how they are configured:

www.gretschguitars.com/support/basic-control-guide

It sounded good with its Filtertrons though, and fine for what it was for. We tried a few options of how best to set it (without mods) and one thing that made a nice difference was to change from his 20' cord to a 10' one.

No-load tone pots would be a great way to get high end back by reducing load. But this could be difficult to create out of dual-ganged pots.

My thought is, do the Master volume if you have a particular need to suit your playing, but otherwise I'd consider ditching it, like most other guitars.

[jlaff]

Yeah, man.  Turning the stacked pots into no-load pots would be awesome but it's out of the questions for me.  I've never even had a pot open before so I doubt that I'm qualified for that type of work (at this particular moment--I'll get there but it might be a while).  I checked out the Gretsch wiring and it's definitely leaning towards what I had planned but it's missing one important feature--independent tone pots for each pickup.  That's the whole point of this current build that I'm doing.

If that doesn't work out, then I can still achieve my aims by using a seperate tone pot for each pickup and a fader pot for blending and then have a master volume pot.  That would take one pot out of the circuit.

When I'm doing the installation, I'll wire an on-on switch to reroute the pickup selector switch directly to the master volume pot to bypass the volume/tone pots so that I can make a tone comparison as I work.

Thanks a lot.

[JohnH]

No-loads are easy to make out of standard 24mm pots, but a PITA with dual-ganged or concentric ones! having a tone on each PU is all fine.

If youd like a switch to help with this, how about its wired to completely cut out the Master volume? You can find out what the tone effect is with/without the MV and if its significant or not, plus, you get a handy 'blower' switch to quickly switch up to full volume for a solo?

[jlaff]

I'm definitely picking up what you're laying down.  I think I'm going to approach it a bit differently though.  Picture this:  an on-on switch that reroutes the pickups directly to the master volume control and a varitone.  Crazy, huh?  Well, this guitar is a Jaguar which comes with 2 seperate circuits and this idea would stay in line with that concept.

So you would have one channel that is the tone-blending channel and then another channel that is simply SD Hot Rails wired to a 1 Meg volume pot and a varitone.  That seems pretty wild to me.  But will it sound good?  I don't know but I do know this:  anything that can be soldered can be unsoldered.  I've got the time, the patience and the cash so why not?

[tubejockey]

I picked up a Gretsch 5220 wired like the one mentioned above.  I has Blacktop Broadtrons in it, which were billed as "the oomph of a PAF with the sparkle of a Filtertron".  There was no sparkle.  The layout of the pots meant that it had about 10 feet of wire going back and forth, with treble bleeds on all 3 volume controls.  It didn't help.  After playing around with pickup height, I broke out the soldering iron and bypassed the two individual volumes, leaving a master volume and master tone.  Huge difference, sparkle was back, even with all the wire left in place.  The middle switch position, with 3 volumes in parallel, was a muddy mess when it was stock.  
Blend pots tend to have similar results, as well as a loss of output through the middle of the rotation.  Varitones lose quite a bit too.

My advice:  Try it out to see what you like or don't like.  Then when you discover that there is no light at the end of that deep dark hole, look at some of the other ways to add tonal variety to a 2 HB guitar.  For example, try out a series/tapped/half-out-of-phase parallel switch for each pickup.  Or a switch that ties each coil to it's own, or the other pickups second coil.  I'll see if I can figure out how to post a schematic.