Tom's Music Page

Guitar Electronics

Gibson Les Paul Standard with Seymour Duncans & CTS push/pulls schematic
I have a Les Paul with a hot set of Seymour Duncans, SH-4 and SH-2N, four CTS 500k potentiometers with push/pull switches, and two .047uf Orange Drop tone capacitors, following Seymour Duncan's recommendation on the pots and capacitors.

While chasing electrons through wiring diagrams for about a week, I could not settle on having dead zones. A final decision was made to follow Gibson's layout of the four push/pulls; coil splits for both pickups, phase, and bridge direct to output. The bridge coil split is meant to be twangy, so I don't see a need to pull back on the tone. The only draw back to my setup is that the bridge tone control is by-passed only when the bridge coil split is selected, but no dead zones.

An alternate setup where the bridge was changed from split to series with itself was considered, but had a drawback of retaining the series mode when set to direct output, we'll see how this setup works out.

- The neck volume push/pull switch splits the neck pickup coils.
- The bridge volume push/pull switch splits the bridge pickup coils, and also by-passes the bridge tone control.
- The neck tone control push/pull switches the pickups to be out of phase with each other.
- The bridge tone control push/pull set the bridge pickup to direct to output.

Switch position summary table
Push Pull controls				Toggle Switch
Neck vol.	Bridge vol.	Neck tone	Bridge tone	Rhythm	middle	Treble
down	down	down	down	Neck	Neck, Bridge	Bridge
UP	down	down	down	Neck single coil	Neck single coil, Bridge	Bridge
down	UP	down	down	Neck	Neck, Bridge single coil	Bridge single coil
UP	UP	down	down	Neck single coil	Neck single coil, Bridge single coil	Bridge single coil
down	down	UP	down	same as above but out of phase
-	-	-	UP	Bridge direct to output

Ibanez RG-550 with Seymour Duncans & CTS push/pull schematic
Used Seymour Duncan Pickups: SH-4, SH-2N, and STK-S4 RWRP, two CTS 250k potentiometers with push/pull switches, a .047uf tone capacitor that are recommended by Seymour Duncan for this pickup configuration.
- The volume push/pull coil splits the humbuckers.
- The tone push/pull turns on both humbuckers and eliminates the middle pickup.
- The optional Bridge Direct toggle switch by-passes all the electronics and connects the bridge pickup directly the the output jack. Throw the switch down to play a lead.

Switch position summary table
push/pulls		toggle	5 way switch
volume	tone	direct	1st pos.	2nd pos.	3rd pos.	4th pos.	5th pos.
down	down	off	Neck	Neck, Middle	Middle	Middle, Bridge	Bridge
UP	down	off	Neck single coil	Neck single coil, Middle	Middle	Middle, Bridge single coil	Bridge single coil
down	UP	off	Neck & Bridge
UP	UP	off	Neck & Bridge both single coil
down	-	ON	Bridge direct to output
UP	-	ON	Bridge split coil direct to output

	    	
Keystone Division 2
	    	
Plum Creek Railroad
	    	
PghTGaus