9

I have been looking for a way to get a truly divided signal from each string on an electric guitar.

The problem is I don't want the signal to be in a midi format because midi throws away a lot of useful information in the signal.

I'm looking into getting a guitar with a divided pickup (like the Roland GK-3), also known as a hexaphonic pickup, and I was wondering if there was any way to get the "raw" (non-midi) signal from a pickup like this while keeping the signal divided.

I would prefer a solution that doesn't require cutting into any wires or hacking together some circuitry myself ... because lets face it, this thing is expensive.

Is this possible? (please note: it doesn't have to be with a Roland GK-3).

Anything that will get me the result I'm looking for would be acceptable.

11

It has been done, in several different pickup designs. These are called hexaphonic pickups, meaning "six separate sounds" or six audio signals, one for each string by itself.

There were a couple of commercial products offered in the last ten years or so by Gibson Guitars and Keith McMillen Instruments that did exactly what you are looking for, but they are no longer being sold. See below.

You can purchase hexaphonic pickup systems from Fishman and Graph Tech that might be capable of being wired up according to your idea. These systems are in the form of six separate piezoelectric pickups installed within an electric guitar bridge -- with a separate pickup under each of the six independent bridge saddles. The Fishman PowerBridge offers this, as does the Graph Tech Ghost system. Each of these require purchasing a bridge-and saddle assembly, and wiring each of the six separate bridge piezo pickups into an internal or external six-channel preamplifier. (These kinds of pickups also are "Roland-compatible" and can use the Roland DIN-13 output jack like the Roland GK-3 you mentioned.)

enter image description here

Graph Tech Ghost piezoelectric bridge elements to be installed in a Stratocaster-style bridge

enter image description here

Graph Tech Ghost internal preamplifiers and wiring kit for their bridge pickup system

The Keith McMillen company used to market the StringPort, a six-channel preamp and analog-to-digital converter that could accept the "Roland-ready" DIN-13 pin output from a hexaphonic piezoelectric bridge pickup, convert all six discreet channels of analog signal into digital audio, and send them all to a DAW in a computer for processing or recording each string's signal on its own separate track. But this product is no longer offered.

Gibson also used to make a Les Paul guitar with a hexaphonic piezoelectric bridge pickup and similar capability, sold with an outboard preamplifier and an external interface box with six separate analog audio output channels. One model was called the Dusk Tiger; the original model in the line was called the "Gibson Robot Guitar". [Note that Gibson has used confusing nomenclature: more recent Gibson instruments called "Robot Guitar" refer to guitars equipped only with an automatic string-tuning system, and not with the original hexaphonic audio output system.]

enter image description here

Diagram of the six-channel "breakout box" for the original Gibson Robot Guitar with its hexaphonic piezoelectric bridge pickup

Brian Moore Guitars make electric guitars that come from the factory with a hexaphonic piezoelectric bridge pickup, and a Roland DIN-13 connector installed internally. I don't know if Brian Moore is using Fishman, Graph Tech, L. R. Baggs or RMC piezo bridge pickups these days, but they should all work about the same. If you had a Brian Moore guitar you'd still need a hexaphonic preamplifier with six audio outputs to plug it into.

Note however that all of the systems described above use piezo-electric pickups, the same kind of pickup used in under-saddle bridges for acoustic guitars. Therefore the sound these pickups produce is of the "acoustic" variety. You would have to use a lot of signal processing to try to make these pickups sound like a conventional magnetic pickup on a conventional electric guitar. You would have to have six separate channels of signal processing (e.g. six separate distortion boxes), whether in the analog or the digital domains.

It would be possible to build six single-string pickups using conventional passive electric guitar single-coil pickup technology, which means winding thousands of windings of hair-thin copper cable around a permanent magnet, but this would be awkward to create. I remember reading about just such inventions back in the crazy days of the 1970s -- there were some prototypes made, but they were never mass-produced and never became popular.

In particular, the Hamer company made such a design for bass guitars, using four separate magnetic pickups, one for each course of string. This would have been easier than a similar design for a guitar, because on the bass the strings are farther apart and there would be more room for those large magnetic coil pickups.

enter image description here

The Hamer Quad Bass as played by Jon Entwistle of The Who

Note the built-in four-channel "mixing board", leading to four separate outputs, one for each string

In the mid-1980s the Kramer guitar company made some guitars called the Ripley line that had hexaphonic pickups that mixed down into a two-channel, stereo output, with a pan-pot for each string. I'm not sure if these were all piezoelectric designs or if there were magnetic pickups involved as well. You can read about them here.

http://www.vintagekramer.com/ripley.htm

Update:

After a Google search I found a one-man company that sells a more conventional magnetic hexaphonic pickup for electric guitars. The company is called Ubertar Hexaphonic Guitar Pickups. I know nothing about them or their products.

http://www.ubertar.com/hexaphonic/index.html

UPDATE TO THE UPDATE

Much to my astonishment I found a current product that does exactly what you want (assuming it is indeed still being manufactured). It's the RMC Pickup Fanout Box. RMC Pickups has been around for many years. You ought to be able to plug any guitar with a piezoelectric hexaphonic bridge pickup and a Roland-Ready DIN-13 pin output into this device. (RMC sells piezoelectric hexaphonic bridge pickups, though these days it seems their kits are only for acoustic guitars, not electric. Have a look around their website.)

http://www.rmcpickup.com/fanoutbox.html

enter image description here

  • Many years ago I had a Brian Moore iGuitar (a cheap Korean one) with a hexaphonic piezo bridge pickup. But I used it for MIDI only, plugging it into a Roland MIDI converter and an Axon MIDI converter. However, I remembered that there were some gizmos for processing hexaphonic audio. The Gibson Robot Guitar to the Dusk Tiger were rather impractical because Gibson only put this technology on high-end, expensive guitars, and I knew it wouldn't last. – user1044 Jun 19 '15 at 10:37
  • The Keith McMillen system looks to be the most promising. It also came with a suite of custom software for hexaphonic signal processing on Mac OS X. But McMillen doesn't make them anymore -- they got into unusual MIDI keyboard and foot pedal and keypad controllers for keyboardists and DJs and those are selling briskly. – user1044 Jun 19 '15 at 10:37
  • RMC is a small company that built in small batches. They used to own the hexaphonic bridge pickup market, but when Fishman and Graph Tech got into that space they took much of RMC's business away. Since the RMC website, ancient though it is, is still up, I'm hoping they are still in business, but I don't know for sure. – user1044 Jun 19 '15 at 10:38
  • It turns out that with divided pickups that have a 13 pin output, 6 of the pins will carry the individual signals to each string so what I want to do is completely possible! I will look into many of the options mentioned in your post. Thanks for the very detailed answer! – tjwrona1992 Jun 21 '15 at 4:18
  • Another item to add to the list of not-available-any-more kit is the ARP Avatar – Brian THOMAS May 12 '17 at 11:52

Not the answer you're looking for? Browse other questions tagged or ask your own question.