Dan Armstrong Series/Parallel Blend Pot Mod | Part 1

Part 2 ▶

Dan Armstrong - A More Versatile Strat

Dan Armstrong's 'A More Versatile Strat' was featured in the February 1987 issue of Guitar Player. In the article, Armstrong describes a wiring modification that uses "only the stock parts" of an S-style and retains "all five stock pickup combinations." This mod alters the stock control layout from Volume/Tone/Tone to Volume/Tone/Fader. The fader control [formerly Tone 2] blends in four new pickup combinations, with the pickups either in series/in phase or parallel/out of phase. All this is clearly explained in the scanned article and wiring diagram [Fig. 1] below, as sourced from AshBass.

A More Versatile Strat. Guitar Player Feb 87, p. 96.

Fig. 1: Wiring Diagram. Guitar Player Feb 87, p. 99.

Breja ToneWorks - Dan Armstrong Series/Parallel Blend Pot Mod  

Breja ToneWorks has also posted a very informative YouTube Video on the 'Dan Armstrong Series/Parallel Blend Pot Mod.' By closely following the procedures outlined by Breja, I reckon anyone with decent soldering skills should be able carry out this mod successfully. Be informed, though, that in contrast to Armstrong's wiring scheme [Fig. 1], Breja ToneWorks has swapped the fader pot's hot [input] and ground tabs [Figs. 7, 14].

Stock Components

The images you will see hereon have been adapted from the aforementioned video. Let us begin by looking at Fig. 2 below, in which stock components have clearly been retained. These include the three single-coil pickups, volume and tone pots, five-way switch, and output jack. 

Fig. 2: Components.

Pot Lugs and Grounding

Before we go any further, I'd like to draw your attention to the lugs on all three pots, which have been labeled L1, L2 and L3 [Fig. 3]. Note that L3 is grounded to the casing on both the volume and blend pots. Following this, we will need to solder ground wires connecting the casings of all three pots, as well as a separate ground wire from the back of the volume pot to the tremolo claw [Fig. 4].

Fig. 3: Pot Lug Identifiers.

Fig. 4: Grounding.

Switch Lugs and Jumpers

Having installed the ground wires, we move on to the five-way switch, which may be a CRL, an Oak Grigsby; or a similarly constructed component. For ease of reference, the lugs on the left side have been labeled A1 to A4, and on the right; B1 to B4 [Fig. 5]. The next step is soldering two jumpers. The first [yellow] connects A1 and B4, while the second [blue] connects A3 and B2 [Fig. 6].

Fig. 5: Switch Lug Identifiers.

Fig. 6: Switch Jumpers and Related Lugs.

Switch to Pot Wiring

Now that the switch jumpers are in place, we may proceed to connect the switch lugs to their corresponding lugs on the volume and blend pots. Three lengths of unshielded wire, soldered on each end to a lug, are used for this purpose. The first connects A2 to blend pot L1, the second, A4 to volume pot L1; while the third grounds B3 to the back of the volume pot [Fig. 7].

Fig. 7: Switch to Pot Wiring.

Master Tone Wiring

Let's shift our attention to the pot in between the volume and blend pots, which is the designated master tone control. In order for it to function as such, one leg of the tone capacitor first needs to be soldered to L3, and the other grounded to the back of the pot [Fig. 8]. Following this, a length of unshielded cable is soldered from tone pot L2 to volume pot L1, completing the tone circuit [Fig. 9].

Fig. 8: Capacitor Wiring.

Fig. 9: Master Tone Wiring.

Pickup Wiring

It's now time to wire in the pickups. Each of the three single-coils has two unshielded leads, one black [negative/ground], and the other in a much lighter color [hot/positive]. Starting with the neck pickup, the ground lead is soldered to L2 on the blend pot, and the hot to A3 on the switch [Fig 10]. Meanwhile, the hot lead of the middle pickup is soldered to A2 on the switch, and the ground to the back of the volume pot [Fig. 11]. Finally, the ground lead of the bridge pickup is soldered to L2 on the blend pot, and the hot to A1 on the switch [Fig. 12].

Fig. 10: Neck Pickup Wiring.

Fig. 11: Middle Pickup Wiring.

Fig. 12: Bridge Pickup Wiring.

Output Jack Wiring

Last but not least, the output jack needs to be soldered to the volume pot. In keeping with convention, light-colored unshielded wire is hot [positive], and connects L2 on the volume pot to the positive [+] tab of the output jack. In contrast, black wire is normally used for the ground [negative] connection. One end is soldered to the negative [-] tab of the output jack, and the other is grounded to the back of the volume pot [Fig. 13]. And that's all there is to it, folks! Fig. 14 is Breja ToneWorks' visualization of the completed 'Dan Armstrong Series/Parallel Blend Pot Mod.'

Fig. 13: Output Jack Wiring.

Fig. 14: Completed Dan Armstrong [Mod] Wiring.