IBANEZ'S BLACKBOX SWITCHES

3PS1CGAE5 (HSH) and 3PS1SC5 (HH)

 

02/28/15- Most pickup selector switches in popular guitars like Stratocasters and Les Pauls are pretty straightforward. Three-position switches (like on a two-pickup Les Paul) are easy to figure out, connecting the output to the bridge pickup in position 1, and the neck pickup in position 3, with position 2 being a switched together combination of both pickups in parallel. Originally, Strat switches had only 3 positions that connected each of the 3 pickups to the output separately, with no combined positions. During the '70s they came out with a 5-position selector that offered the 2 extra combined positions-- an easy enhancement, since all they had to do was put 2 extra detents in the frame for the bearing that held the lever in the selected position. If I recall correctly, the CRL-style switch is basically a 5-position switch with two sets of poles. One set of poles is for selecting which hot pickup lead goes to the output and the other set is for selecting which positions connect the output to either of the two tone pots. (Personally, I've always thought it was quirky and weird that the bridge pickup had no tone control...)

With the growth of interest in coil-split/coil-tapped humbuckers, in-phase/out-of-phase, and series/parallel wiring, there's been a corresponding growth of interest in how to wire all these possibilities, and in the switches that are needed to do it. Consequently, 4-pole/5-position lever-style "superswitches" (like the CRL and Oakley) were manufactured that let you "program" connections for each of the five positions. The switches themselves are relatively easy to figure out. The fun (for some folks) challenge is to figure out how to structure the pathways to get the circuit to do what you want it to do. It's like programming through hardware, and can be a mind-bending exercise. (Equally mind-bending is trying to figure out what the switches do if you haven't used them in a while.) There are plenty of websites with great information about popular superswitches and the wiring to get all the aforementioned configurations, and Google is your friend for finding them (if you don't mind friends who stalk you, nyuk nyuk).

This article deals with the two weird switches (3PS1CGAE5 and 3PS1SC5) that Ibanez has put in many of their guitars to achieve similar results. Why bother with 'em? Because those are what came in the Ibanez guitars that I bought, and sometimes they're the only thing that will fit. It's been hard to find tinkerer's information about them on the web, so I've been forced to get out my VOM to figure them out again. There are plenty of Ibanez connection diagrams out there, but if you want to riff on variations of the standard wiring, you need to know what's inside the blackbox.

First off, if you've got the space, a CRL-style superswitch is likely a better, more reliable choice. They're made of four sections of contacts, with a more robust/reliable slider/contact system than the wiper-on-printed-circuit board design. I believe that also applies to the upscale Ibanez vlx91 switch (which I understand is also a 4-section switch); although I don't have one, pictures seem to indicate that it's a pc-board switch. The 4-section switch gives you ultimate freedom to program the operation of the switch with jumpers, at the cost of taking up more space. The pc-board construction is more compact, but comes at the cost of reliability. A big plus is that they're basically just a simple 1 x 5 position switch, multipled by 4. No secret blackbox innards to make it difficult to figure out what's being switched.

The 3PS1CGAE5 and 3PS1SC5 switches aren't top-shelf switches, but they're not poorly-made or poorly-designed. Basically, they were designed to provide coil-tap functionality in as small a space as possible, using standard (cheap & easy) manufacturing techniques for the masses (that's us). No mil-spec features. They achieve coil-futzing functionality on a single pc board layer with preprogrammed connection paths for the 8 pins, depending on the 5 selector positions. This saves space, but makes it more challenging to figure out ways to make the switch do things that it wasn't specifically designed to do. And that's the main reason for wanting to understand how the switches work.

Outwardly, both switches look the same, but they're not. They're purpose-designed to connect the pickups in specific ways. Therefore, using the stock wiring diagram, they aren't interchangeable: They're different inside, and you can't easily figure them out by just looking at them, hence the term "blackbox".

Generally speaking, both switches have two groups of contacts that make contact with various pins in the different positions. Although the pins are mainly divided into a hot/signal set (pins 1-4) and a ground set (pins 5-8), some pins can be jumpered to serve either role for parallel connections (as the HH switch does). Both switches have a "hot" bus (pin 4) that's present in all positions, serving as the output. The HSH switch also has a (potential) ground bus on pin 5.


To trace the circuit through the table, choose a pickup selector position and note which pins are connected in the table (1-8 on the right hand column). Find those pins on the switch in the wiring diagram and follow where the wires go.

HSH Configuration: This is a pretty straightforward wiring design, and the symmetrical switch table (orange and green connections are mirror images) reflects the symmetry of the actual pickup wiring. The only slightly fancy thing is the splitting of the humbuckers in positions 2 and 4.

The humbuckers' split coil taps connect to ground (pin 7) through pins 6 and 8, depending on the position of the switch. This gives you one coil of the humbuckers when they connect in parallel with the middle pickup in positions 2 and 4.

 

.

(bottom) I think Ibanez got the bridge and neck labels wrong on the selector switch(?): The pc board side is usually near the edge of the body, which would make the bridge position downwards (nearer to the bridge pickup), or to the right in the diagram.


HH Configuration: The HH 2-pickup diagram is much more complicated and more difficult to trace than the HSH shown above. In trying to fill the five selector positions with only two pickups, the switch is doing some tricky series and parallel stuff.

The jumper on the switch from pin 2 to pin 7 makes some of these combinations possible and adds to the challenge. They had some really smart people figure this stuff out!

To understand the wiring of a switch like this, It's helpful to make 5 copies of the wiring diagram and trace the connection paths for each position.

Again, I had to make some slight corrections to the Ibanez wiring diagram to make it jive with my table.


 

GUITAR INDEX