"Blue Indy", a SHS S-style

[stevewf]

Here's Blue Indy, a strat-based 3-pickup guitar with added series, out-of-phase and hum-canceling features.





The guitar body and neck have been together since original purchase as an Indio (by Monoprice) "Cali Classic HSS Electric Guitar" but many things surrounding the neck & body have since been changed.

This guitar was adopted for modding because its neck played very well, despite the cost being very low. The one minor drawback in choosing this guitar was that the pickguard mounting holes didn't match the standard (which is the arbitrarily chosen stratosphereparts pattern).

Obvious differences from a standard Strat include:
Pickups: P-90s in the Neck and Bridge spots, and a HB Rail in the Middle
Added switch: a mini-toggle between two of the control knobs
The body heel has been re-shaped, matching the new curved neck mounting plate

And some less obvious mods:
The body cavity has been enlarged in 3 places to accommodate the new electronics
Made deeper under the selector blade switch as a precaution against short-circuiting with the shelding
Made wider for the 4P2T mini-toggle
Excavated for the 4P2T push-pull switch
The pickguard is provided with only 2 pickup holes but there are 3 pickups; the middle hole was added by the owner, as was the mini-toggle hole
The original pickguard mounting holes don't match the pickguards from stratosphereparts, so the body was redrilled.

Additionally, much hardware's been replaced:
Tuners have been replaced with black HipShot locking tuners; these left mounting holes unused in the headstock
Trem replaced with a Wilkinson unit; fit without modification
Knobs from Qparts
Pickguard from stratosphereparts; body plugged and redrilled to match the 11 mounting holes
Black jack and plate
Curved (black) neck mounting plate

Electronics, too:
4P5T "Superswitch"
Custom push-pull switch
Added mini-toggle switch
Swapped in A500KΩ Pots for Vol & Tone
Modified pot wafers for Fader


Many, many thanks to Yogi B for helping to create this scheme, here


Function
By design, the two-pickup combos are hum-canceling when possible (i.e. all but Neck & Bridge). Pickups, controls were purposefully selected/created in order to enable this.
A table of the pickup coil combos available:

Switches			Output
S/P	Phase	5-Way	Pickup(s)
Series	In Phase	1	B
		2	B × (MN + <Series Fader>)
		3	B × (N + <Series Fader>)
		4	−N × (−MS + <Series Fader>)
		5	−N
	Out of Phase	1	B
		2	B × (−MS + <Series Fader>)
		3	B × (−N + <Series Fader>)
		4	−N × (MN + <Series Fader>)
		5	−N
Parallel	In Phase	1	B
		2	B + (MN × <Parallel Fader>)
		3	B + (N × <Parallel Fader>)
		4	−N + (−MS × <Parallel Fader>)
		5	−N
	Out of Phase	1	B
		2	B + (−MS × <Parallel Fader> × Cap)
		3	B + (−N × <Parallel Fader> × Cap)
		4	−N + (MN × <Parallel Fader> × Cap)
		5	−N

Thanks to Yogi B again, for this table

This incarnation is the guitar's third. First was its factory HSS setup (monoprice.com) which didn't even split the HB when in Pos#2, sheesh. Its second form was pretty close to the present setup, but it used a pair of 4P2T slider switches; that setup didn't feature filtering the parallel out of phase combos.

For its third life (present), it has had two changes to its switches: a custom 4P2T push-pull switch and a 4P2T mini-toggle replace the pair of sliders. Also, the middle pickup was swapped for a higher-output one. Along the way (v3beta), the guitar had a 6P5T blade switch, created in a failed attempt to provide the Parallel, Out-of-Phase capacitor filtering ("PFOoP"), no longer in this guitar, since a standard Superswitch does the job (thanks to Yogi B!).

Push-pull switch

 Harness buildout on a temp pickguard (custom P-P switch seen at the bottom of photo)

This second attempt at a dual 4P2T push-pull has so far lived longer than the previous. The previous failed because it allowed the "sidecar" commuter block to tilt within its chassis instead of sliding, thus causing one of the poles to fail to "make" the connection to the "Down" throw terminal. In the re-done version, the blocks use the same method of linkage, but this time with a better-positioned link pin that lessens the tendency to tilt.

Assembling the new switch blocks together needed the assembly of the pot chassis (whose bendable tabs need shaping during assembly before the sidecar gets added). During the assembly, it became clear that the unit functioned better with the sidecar's position slightly off-square, so this is how it was fixed. The sidecar chassis is fixed to the main switch chassis using only two solder points, despite the increased risk of breakage, to avoid melting the plastic parts during attachment and to make disassembly easier, should it be required.

Cavity altered
In order to accommodate physically the new switches, the cavity was carved out in three places: 1) under the selector switch, thinning the back wall of the cavity, just to make sure the switch's terminals weren't connecting with the copper foil cavity liner; 2) to accommodate the bulk of the 4P2T mini-toggle in its desired position, a notch, obscured by the pick guard, was carved out of the body; 3) an extension to the cavity was dug out, cave-like, to accommodate the bulk of the new push-pull switch, which is under the "last" knob. The lateral depth of the cave extends beyond the pickguard, so it was excavated while leaving the body surface intact.


Altered cavity

Middle Pickup
The Strat-sized dual rail pickup that's currently in the middle spot came from stratosphereparts.com, apparently no longer available for purchase. This pickup was chosen over the previous GFS Li'l Killer because its higher power more closely matches the P-90s'.

Fader pot
The fader pot took the physical spot from the Middle Tone knob. It's a dual-gang pot; one wafer is for fading while in Serial mode, the other wafer being for Parallel.
Series: In order to obtain true 100% signal from the faded pickup when turned all the way up, the track of the serial fader was cut near its fully CW ("10") end. This wafer is an audio-tapered 250KΩ pot with its track cut just below the "10" mark (A250K cut<10).
Parallel: In order to obtain true 0% signal from the faded pickup when turned all the way down, the track of the parallel fader was cut near its fully CCW ("0") end. This wafer is a reverse-audio-tapered 250KΩ pot with its track cut just above the "0" mark (C250K cut>0). Note: to obtain a "C" taper in the 2nd wafer spot, an "A" wafer from a separate pot was flipped, cut, and placed in that spot.

Since the Fader got its location from the Middle Tone control, there's now a Master Tone instead (the 2nd knob).


(Cuting the resistive tracks. note: the wafer on the right was later replaced with an A wafer, which, inverted inside the pot, performs as a C taper)

This guitar has come a long way from the test bench.

Early stages, in the "Ash Lab", choosing the location of the middle pickup

A gallery of more photos is here: postimg.cc/gallery/FJ655xd

Thanks to all the GuitarNuts who've helped!

---

Is a customized guitar ever "done"? Here are my remaining Hopes, Wishes and Maybes:

• Try a higher value FOoP cap in order to make the Parallel, Out-of-Phase sound more distinct (thinner, weaker)
• Build another 4P2T push-pull switch for the Series/Parallel switching, thus doing away with the mini-toggle. The P-P switches could then be positioned more like JohnH's "Strat SP" for consistency.
  
• Flip the magnet of the middle rail HB (and swap its wires, too, for phase) so that the OoP coil is the coil that's further from its P-90 OoP partner; it may sound better (more traditional strat "quack" and/or more distinct OoP sounds.
  
• Paint the heel where it's been cut
• Thin the headstock where the tuners go through by milling/routing the rear. This headstock is thicker than others, so the staggered tuners barely reach through. A fancy rout would also give a chance to do some ornamental work.
  
• Remove the factory logo from the headstock; further, maybe replace it with a custom one (yet to be designed)

[cynical1]

Very nice. I like how you just kept modding the guitar over time. A good neck is a good neck.

HTC1

[stevewf]

Yes, the guitar kept getting modded. First, at its price, I was thinking of modding it before I'd even paid for it.

Since I started drawing plans for a new setup, this guitar has been about the pair of P-90s. But a plain ol' 2xP-90 Strat seemed too, well, plain; we can pretty much get a guitar like that off the shelf. So this is about P-90's Plus.

The P-90s had to be a hum-canceling pair (when in phase), just like off-the-shelf. I also wanted out-of-phase (OoP) sounds with each P-90, so there had to be two more coils added. The middle spot seemed the obvious placement.

While the middle pickup's main job was to provide OoP sounds, it seemed a shame to pass up the opportunity to use it also for its In Phase sounds, especially since the 5-way blade is a standard.

---

This guitar, again, was about the P-90s. It struck me along the way that the same sort of scheme could be done with normal Strat pickups instead of P-90s. One day I might try. If I do, it could be done a lot easier by using Fender S-1 switches. They'd be under standard Fender Strat knobs (which is a reason I made my own 4P2T switch: I wanted prettier knobs), and so they wouldn't need cavity carving. That way, aside from the dual-rail middle pickup, it'd be a stealth mod. Oh yeah, and the other giveaway would be the 2nd "Volume" knob on the 2nd S-1 switch. One day!

[kitwn]

It's a very pretty guitar, although it's always dangerous to listen with your eyes, though the picture that really wins it for me is the "Ash Lab". A bit of effort to make in the first place but what a useful tool for quickly testing all the switch combinations you can imagine and finding out which ones are worth the trouble and which not. Everybody who seriously wants to build/mod guitar electronics needs to make one of these.

Kit