First post/question, so please pardon my ignorance. Some context: bought a Casio MG-500 new decades ago. Which is to say conversion latency was unacceptable even back then. Stumbled upon MG3Hex. So,
Goal today: To use fast 600 MHz microcontroller-USB device directly connected to Roland GT3 hex pickup board to send ‘the needed data’ to MG3Hex via microcontroller’s USB-C port.
I’ve read up on post re MG3Hex and GT3, and the GP10 - e.g. setting must be “Dry-Guitar” not USB Audio (Oct2025 by JamO).
To quote Dutti67: “All what MG3Hex takes from any Boss device are the 6 audio signals coming from the hex-PU. All internal stuff is “bypassed”. Whatever you simulate within such a device has no influence to the raw audio signal from the PU.”
Dutti67’s statement seems to indicate that a full Midi Library loaded onto the microcontroller is not even needed, for as long as the output from each of the six pickups is sent to individual analog pins on the microcontroller and relayed to the USB-C port in the proper format expected by MG3Hex.
With such an inexpensive working interface (which shouldn’t be that difficult to set up) dedicated midi guitars such as the Casio MG-500 or Jamstik would not be needed at all - MG3Hex would (like Loopy Pro), decimate the need for pricey Boss/Roland (loopers) synths/sound modelers.
Best of all latency would be nearly non-existent.
So the questions are: What is the format of the data expected by MG3Hex? Will the setup as described work, and if not, what’s missing?
MG3 Hex must receive 6 audio streams, therefore your idea using the Casio MG-500 controller will not work because it sends MIDI through the USB connection.
My apologies (@dutti67). I was not suggesting the use of my ancient Casio MG-500 at all.
Rather, I am suggesting a full internal Roland GT3 Hex pickup kit (on any ordinary electric guitar) with its small board connected directly to a microcontroller’s analog pins (i.e. the Teensy 4.1) with Midi Library loaded (but likely not fully required) appearing as a USB device to the MG3Hex, connected via the Teensy’s USB-C port.
Right now (it seems), a GT3 Hex pickup + GP10 can be used with MG3Hex via the GP10’s USB port (Channels 3-8 dry), which is connected onto a USB hub with all other devices. Please correct me if I am wrong.
Would welcome any suggestions and information on exactly what data, format, etc that MG3Hex expects to receive, to get this setup to work.
There should be no need to purchase an expensive Roland GP10 or Boss GR 20 to 55 let alone GM800 or SY series just to connect to MG3Hex.
If successful the template hex board + controller would increase MG3Hex sales dramatically - because it would make low latency affordable and gig-able.
Currently, there is no commercially available product that meets the requirements in terms of cost and size. You would have to develop a 6-channel audio interface from scratch. The cost of that is virtually impossible to estimate.
The Teensy 4.1 you mentioned only has one “experimental” audio input, but you need six fully functional inputs.
All I require is precise info on what MG3Hex needs to see.
In a previous life I made equipment far more complcated from different vendors talk to each other.
Breakout cables to a Behringer audio interface seems so 1980s. Just like I would not use my Casio MG-500 internal midi into a GK adapter for a GM800 today.
Am not inclined to purchase a proprietary Jamstik either. So I am looking at the MG3Hex.
I don’t know what I did in previous lives but in this current one I tried exactly what you are trying to do and had to give up. Even well experienced audio application designers didn’t want to touch this subject. The difficulty is the number of channels needed to be processed. I still think that it is possible and probably the easiest way is to do a reverse engineering of the audio → USB part of a GP-10.
I wish you good luck!
@syzinteg, thank you for your courage and impartiality.
Why only 6 channels? I would think further to at least 10 (e.g. for Chapman Stick).
And then the new interface should enable the sound range to be transmitted from the lowest note B0 (bass guitar) to the highest note of a string instrument such as a guitar, mandolin, or violin…
And all this with a latency of just a few milliseconds.
@Dutti67 has described the current status well. This project is very difficult, even for an experienced electronics engineer, but not impossible!
As long as a USB 3.1 connection (5 Gbit/s) proves to be sufficient, such a special audio interface would sell like hotcakes. Perhaps with the likely market launch (in summer 2026) of Bluetooth 6.2, a low-latency connection will also be possible, which is also a very frequently requested feature.
@syzinteg, get started and we are all looking forward to your next progress reports.
In a nutshell, MG3 Hex setup always incorporates a hexaphonic pickup and a device that delivers the six individual audio feeds, one per string, over USB to the computer runing MG3 Hex.
For the hex pickup, users commonly gravitate toward a Roland GK-2A, GK-3 or GK-5. There are other systems one can look at, but Roland’s hex pickups are the most accessible.
You can use a BOSS GP-10, SY-1000, VG-800, GM-800 to send individual audio channels per string to your computer / MG3 Hex. This is what your hex pickup connects to via a 13-pin cable.
For users who are not interested in these particular hardware devices, you can connect your hex pickup via a breakout cable to a multichannel USB audio interface.
Do yourself a favour and find a cheap used GP-10/GK-3/13-pin cable combo.
I completely agree! Ideally, someone with excellent electrical engineering and programming skills should try again. Hardware development is one thing, but writing the firmware for the controllers is a completely different challenge.
Does it serve MG3Hex (sales and community) to say “Do yourself a favor” and buy a GP10 and interface with 6 inputs, make a breakout cable to your GT3 hex pickup? Yeah, as mentioned here somewhere: “All 50 of us” on this forum would.
30+ years ago I was already using a Casio MG-500 on Roland to get both modeled sounds and latency. Haven’t checked, but the GP10 likely came out around that time.
MG3Hex is the progress I expected from today, so it is what I intend to use, sans latency where avoidable.
As mentioned all I required is precise info on what MG3Hex needs to see. I could sniff it out (as I do today on non-musical electronic devices) but then I’d rank the effort as pro, and not hobby.
Best regards to all in the forum. Thank you for your time.
P.S. @anjo I am a big fan of Maestro Bob Culbertson, the Chapman Stick Mozart. Yes, the device should be able to easily expand beyond six strings.
you’d be engineering a solution for a piece of hardware which may not be in prime shape and is probably not replaceable (the hex pickup on the casio).
before doing so it may be worth your while to examine the output the pickup is producing currently.
there are many who advise wax potting and other techniques for optimizing/preserving roland hex pickups. as yours is quite old and may not have been wax potted etc, it may not have aged well.
good luck. the vguitarforum is probably a better place for you, you don’t seem happy here.
As mentioned in the thread (respectfully), I have no intention of using my ancient Casio MG-500. I am using a new set of internal Roland GT3 Hex pickup and board(s) onto a microcontroller to fit everything into an ordinary electric guitar.
Apologies if I seem ‘unhappy’. I’m very glad for all the advice. I’m just looking for information.
MG3Hex is a product that I’ve been waiting for, for decades. It just needs an equally modern direct interface.
To answer your question @syzinteg, MG3 hex needs to see 6 audio streams from some type of audio interface that can be recognized by either macOS, iOS, iPadOS, or Windows. This could be analog or digital. If you can come up with a way to get a Roland hex pickup (or any hex pickup) to do this, I for one would be interested in it.
I do currently use the Boss GK-5 to a Boss GKC-DA convertor to Separate Strings 13pin 6 audio out breakout cable to a multi input audio interface. I prefer this over a GK3 as the TRS cable for GK5 is a much better cable and not near as stiff. But if there is a way to minimize all of this, this would be very interesting. Please keep us informed of your progress.
otoh, imagine posting such a request on the ableton or protools forum.
at least here people tried to be helpful.
the information you seek is documented in abundance elsewhere. there is nothing unique about interfacing with mg3hex, it is just the same as interfacing with ableton live or protools etc.
if you care to do the legwork, you’ll find i’m correct. jamo has no responsibility to walk you through your process.
Hi @syzinteq , you’ve come to the right place here in the forum, and you’re very welcome here.
For anyone who wants to get started right away, the solutions suggested by @Dutti67 and others are still valid, but they are also outdated and involve considerable equipment and financial investment. The cheapest solution from Sixstring Billbax with 6 cables for GK3 is manufactured in the UK, but unfortunately is not sold in EU countries.
But finally someone is saying it: MidiGuitar3 Hex needs a modern interface! Not just for Roland GK pickups, but for all 6-10-way pickups of any kind and affordable for everyone.
You should definitely use Vguitarforums as a second forum (some people from this forum do too). There are also good electronics and software specialists for audio there who are very helpful.
Yes, you’re a dreamer until you’ve implemented your idea. Sure, but otherwise @JamO’s visionary MidiGuitar3 would never have been created (over 17 years ago).
My experience so far in the forum and in personal contact is that @JamO is very helpful and accommodating, and I am sure he will help you obtain the information relevant to you.
@Dutti67 and others here are more competent with hardware solutions than I, but what I can say is that if you come up with any kind of solution that feeds 6 or 10 channels of digital audio into a PC or Mac, via USB (or somehow circumventing USB to read a steam of bits directly), we will make MG Hex support for this device. All that is required is that the audio samples from the device can be read in a predicatable way.
i just read that gumtown’s speed test of the gk-5 in combination with the gm800(?) offered the slowest response of any roland gk interface going back to the beginning.
is there additional latency added by the a/d stage? it seems like a giant step backwards.
what features are lacking in currently available multi-channel interfaces?
in my view, what would be most useful is a multichannel interface capable of fitting inside a typical guitar cavity.
ideally that would be paired with an onboard tiny pc, but even if not all you’d need would be a single usb cable, which would also provide power (which is yet another non-trivial challenge).
That must be with the newer Boss/Roland synth boxes. I don’t have any latency issues running the GK5 with the GKC-DA. I have GK-5s on 3 different guitars and don’t have any real latency differences from regular MG3 mono input. I have been switching back and forth today between my main guitar with GK5 and a new nylon electric with piezo bridge and mono MG3 and both work equally well. I do wish I could get a pickup for they nylon string (Kiesel AC26 nylon), but you need steel strings to work with their pickups.
To each his own. MG3 in either mono or hex is worlds beyond anything Roland/Boss has out. MG3 just lets me be creative without having to worry about the technology. As always, many thanks to @JamO for creating this magical software.
Kimyo, you are mistaken. the pitch to midi speed of the VG-800 and GM-800 are the fastest Roland/Boss devices to date. Quit spreading bullshit. The only device faster is the Tripleplay. And Midi Guitar 3 is slower than both. These are the facts! I know you are a Roland hater, but don’t let that lead to spreading lies. What is this Gumtown speed test you are referring to?
