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A Guitar Schematic I've Grown To Enjoy


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Thought I'd share this with everyone. Probably not everyone's cup of tea, but it does give very useful tones and there's not a huge volume change between the different settings (something I tend to like).


I used this on my Les Paul BFG rewire.

Basically you get all the normal LP (or twin pickup) tones, plus you get pickups in series for a phat tone, and pickups not quite out of phase for a Strat tone (not the thin wimpy nasal out of phase tone you normally think of).

The 4p3t switch is wired like this:


One of the pickups (preferably the neck) has to have its ground lifted, iow, it needs two signal wires, and a ground wire for its own hum prevention. All 4wire pickups do this. The 3wire pickups also do that. Most "braided one conductor" pickups can be converted if you're ok working on pickups. If the normal position of the rotary switch gives you out of phase tones when you're using both pickups, just reverse the red wires on the diagram.

I've been using this with a p90 in the neck and HB at the bridge - the BFG setup - and very much pleased with the tones. The next Tele build will have this setup for wiring, no question about it.

One thing I like about it, is you get a toggle, thats useful for live play, and gives you expected results. Yet you get some special tones too via rotary if you want them (more confusing in a gig, but not unbearably so... as was the Gibson L6s' rotary switch).

The other thing - a real winner - is the Lawrence Q-filter for use as a "middle" control. It knocks out the mids, and leaves the sparkle of the highs. Amazing device (although you need to experiment with cap and resistor values a little, to best match your pickups)

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Thanks, CB, this looks interesting. I'm a bit of a noob so bare w/ me here. Is the 4p3t switch a rotary? Do you have a link? And is the Q-Filter a separate thing? I looked it up and it appears so. I have a guitar that has the Seymour Duncan JB/59 combo in it and I think this would be a cool mod. the JB is 4 conductor and the 59 is 2. Which leads me to my final question - How do you convert a 2 conducter pup to a 4-conductor? Is there a good resource w/ pics on the web?

Thanks again for the cool post. I'd really like to try this once I wrap my head around it.

Edited by dap9
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Is the 4p3t switch a rotary? Do you have a link?

And is the Q-Filter a separate thing?

How do you convert a 2 conducter pup to a 4-conductor?

The 4p3t switch is in fact a rotary. Any 4pole3throw rotary will do - assuming the physical size is ok. The company ALPHA is sold by Mouser (electronics distributor). Alpha makes a lot of different switches. Most are under $3 each. You can get "make before break" and "break before make" options on many rotary switches. Have a look at www.mouser.com and do a search on "4p3t rotary". That should get you started.

Mouser part # 105-SR2511F-43RN


Price $2.20 (plus shipping)

The Q-filter is great device. Its made by Bill Lawrence (the real Bill, not the folks using his name). He says its a .9hy inductor, but the ones I got both measure 1.85hy each - a GOOD thing imho, as the higher the henries (assuming low impedance) the more highs are retained. The L6s has a 1.5hy inductor, as also does the real Gibson Varitone. These can be just a bit lacking on the high end sparkle (depending on how you set it). The Q filter does the job really well, and measures about 3/4 inch square.


Note, the picture is old. Price $20.00 plus $7.50 shipping (no matter how many you buy, its only $7.50 for the whole order, flat rate).

To convert a 2 conductor (1 wire with braid) to what we need is pretty simple. Generically -

a. Remove the cover from the pickup, and or remove the OUTER layer of tape

b. Tease the leads out from their resting place between/under the coils

c. Carefully unwrap their tape

d. Desolder the 1 wire with braid. The braid is connected to the pickup frame, one of the lead wires is also connected to teh pickup frame, desolder it from the frame

e. Wire the leads to two wires of the 4 wire cord you've supplied. Note the white lead from the pickup is "hot" and black is now the opposite of hot (but no longer ground). I chose black and red to with red to white and black to black inside the pickup.

f. Wire the bare ground wire on your cord to the frame of the pickup.

g. The white and green wires can be pulled from the 4 conductor sheath if you want. Alternately... instead of wiring the bare wire to the frame, wire the green wire to the frame and just have 3 wires coming from the pickup, no sheath at all. Naturally, the green wire is ground

h. Re-tape the connections and tuck the wires back safely between the coils

g. Replace the covers or outer tape on the pickup (use fresh tape)

What we want is not really a "4 wire" pickup, but a "2 wire, with separate ground" pickup. If you have a 2wire pickup (wire plus braid) and a 4 wire pickup, no rewiring is needed. Just use the two signal wires and keep connected those two wires that need to be connected for the pickup to work. Usually its the white and green that get tied together, with black and red being signal wires and the bare wire ground, but not always. See the following diagrams for your particular pickup brand:


Thanks for the interest!~

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Thanks CB! When I first read your post I was at work so the image didn't show up. Once I got home I was able to see your schematic which will help. I'm still learning how to read those, but yours seemed laid out nicely so I'm sure it'll be easy enough to figure out.

Thanks for all the explanations on the Lawrence thing and converting the 2-wire pup. Some of that was a little Greek to me, but again, I'm new at this and it gives me reason to look stuff up (like henries). I like all the learning.

I'm not sure when I'll get around to this mod, but I'll print the stuff out and study it for a while so I know what I'm getting myself into. I kinda want to do it on an ES-335 copy I have, but I'd have to get new pups to do it. Rats! :D More gear :D

Edited by dap9
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