JEM style pickup wiring

A dissection of a live specimen

My default wiring approach

So, arguably I have plugging away at wiring setups that treat each pickup as a separate unit, in contrast to a holistic set of sensors intended to work together.

Sometimes these have been variations on the Strat wiring theme with a wrinkle: like coil taps for humbuckers,

HSH circuit diagram

or parallel / series combination for the humbuckers

The 30 year tune-up: serious and parallax

BTW, [confession time]: I upgraded one HSH to parallel / series, mainly to retain the noise rejection that would have been undermined with coil tapping the humbuckers.

Essentially though, the scheme is simple: select a pickup; for some special positions you get 2 (occasionally 3) in parallel.

There is another way

But with the recent purchase

So, I bought another guitar…

I get the chance to look at a pretty recent, stock guitar — “it’s been a while since that happened”

So, this guitar has the JEM wiring

How Steve Vai's Ibanez JEM Revolutionized the Super Strat

Initially popularised in the JEM range, and implemented in many other of the Ibanez range to this day, including the S771.

Reality check

Ok, it does sound broadly similar to the other schemes: your average newbie will not be able to tell much difference.

But

There is a different paradigm at work here: much like Paul Reed Smith’s assertion that “they’re just the microphones”, we leave the old model where pickups were labelled “rhythm” and “lead”.

Digression. As an eighties kid, coming across a (knock-off) guitar like that blew my mind. Initial thoughts: “why that way around?” and “then what about the middle position?”, “Both?”, “Neither?!!”

So, if we follow the paradigm that “they are just microphones” and we know that most good recordings are achieved with multiple microphones, surely it seems legitimate to mix together what “sounds best”?

Problems arise

Most will probably be aware and agree that the majority of legacy and modern wiring schemes do not allow just any combination of pickups to be dialled in. Some more expensive boutique setups have been available for years that allow this, but either it never caught on, or guitarists did not become as rich as the sales projections predicted.

The constraints / reasons are many…

Passive electronics

With this technology choice, you can only ever realistically cut signal frequencies. And typically, guitarists have already been fighting since forever to get enough signal, while retaining the tonal characteristics, so historically at least losing signal was not going to be popular. Arguably, in recent times buffering and gain have become very widely accessible, but the core electric guitar spec. is still legacy compatible.

Hence, although some passive tone shaping is possible, quite reasonably the primary approach has been blending frequencies arising from different pickup with this, unless you load the guitar with kilograms of magnets, compromises will have to be made.

Constraints of the pickup paradigm

We’ve touched upon some of the constraints of the passive pickup design above; in addition, merely connecting pickups to each other alters their tone.

So now the designer has to consider whether the combinations of pickups offered make varied and pleading sounds, in addition to their independent sounds.

The uncanny valley

Finally (for now), the electric guitar is to an extent an audio and cultural artefact: people expect certain types of sound, albeit jazz, country or rock or even

You can’t stray too far from those parameters or people will not like them.

To be fair to manufacturers, there are many factors that will attract people to buying an instrument — guitar heros’ models, favourite albums, classic designs, colour, finish.

As an example, I was blown away when I found in one of my favourite songs that

https://www.amazon.com/In-Your-Eyes-2012-Remastered/dp/B07D1FX67F

was not a synthesiser, but in fact guitars… — check out 1:05 in the full recording

The JEM style wiring

Whipping the back off — the “buckle rash” was already there, honest.

initial view of a nice tidy control cavity

A close up on the switch

left had side of the switch selects the pickup; the RH side either routes the signal through the other humbucker coil or shorts it out

This should represent the pickup selection logic (omitting tone controls)

A little bit naughty

So the single coil has no shielding on the 2 wires ; I’m not sure how well the cavity shielding paint is working, but I did notice the single coil on its own has more noise pickup than any of the other guitars, which are shielded to the max. When combined, I would seem the phases have been configured to allow the hum bucking principle to operate for the in-between positions.

Noisebusters — the Movie

How Does it Sound?

Conclusion

It’s simple, clever and effective.

Does it make a huge difference? Not really?

The in-between positions are quite bright and jangly, which is nice.

The primary benefit I would hazard is that it allows high output humbuckers to be matched with a lower output single coil while retaining the ability to have a good variety of tones easily dialled up.