Making your own MIDI Guitar Synthesizer - Part 1

Hardware Guitar Synthesizers have now been around for decades and it would be fair to say that the technology could be considered as mature. That said, commercially available guitar synths are still expensive and perhaps surprisingly, somewhat cumbersome to use.

The purpose of this article is to provide information for guitarists to set up an effective and affordable software alternative to the mainstream hardware MIDI guitar synths. This article explains what components you need to get the show on the road.

I'm currently running my guitars through a Casio WK-7500 (Keyboard) and Roland U-220 Sound Module (Synth of sorts). Since I'm running the synth outputs through my own simple but very effective Stereo Guitar Effects Patch Bay, I can have raw guitar, guitar effects, guitar synth or any combination of these ... in real-time.




Just to be clear ... This article is not about building your own hardware guitar synth. If that is what you are after, there are still a few (now almost uninhabited) forums out there, that have been flogging that particular dead horse for some years.
   

So ... Back to the story ...

Overall it would seem that guitarists simply haven't taken sufficient interest in MIDI / Synthesizer technology. At least, not to the level required to bring the price down and move the technology forward at the same pace as other guitar effects.

By now I would have expected that just about every electric guitar made (and at least the high-end ones) would be MIDI Ready and come pre-fitted with the required Hex Pickups as standard (see the Godin xtSA). It's just not that big of a deal. Sadly, the cost of hardware guitar synths means that they are still out of reach for many nonprofessional guitarists.

This particular project is based on (and made possible) by software written by some Danish lads (at JamOrigin) called MIDI Guitar. The input to the MIDI Guitar software can be either Monophonic (single notes) or Polyphonic (chords). More about the features and parameters of the software will be discussed later in this article.

At the time this article was first written the MIDI Guitar software was still in Beta (v 0.61), but was none the less fully functional (impressive actually for a Beta). I liked it so much (even back then) that I purchased and registered a copy. I still love it and continue to use it! Even though I now have a small collection of Roland/Boss guitar synths.

Supporting this software will help to ensure that development continues. Please do.



PLAYING STYLE

There is one requirement for guitar synthesizers, that really hasn't changed over the years and probably won't change (at least for some time to come):

To successfully use a guitar synth requires a meticulously clean and accurate guitar playing style.

This may in fact be the reason why guitar synths haven't caught on ... in that the guitar playing is too much like hard work for many guitarists.

From using the MIDI Guitar software, I have noticed that the note identification happens on the attack peak at the start of the note. So it works well with a Guitar Pick, less well with Finger Picked notes. It is almost a given that you will need to adjust your playing style for best results.

Note: The V2.0 Beta (which I have used now for a few months), does address some of the 'playing style' issues. However, adopting a cleaner playing/picking approach still helps in getting the note that you intended.

Worth noting though is the stated intention by the MIDI Guitar programmers to eventually completely remove 'playing style' from the performance of the MIDI Guitar software. I wish them well ;-)


THE GUITAR

Just about any electric guitar should work, though some will no doubt work better than others. This will mostly be due to the way the guitar is set up.

Ideally the guitar needs to produce a clean signal within which the notes (including notes in chords) can be easily identified. That is so much simpler to say, than it is in reality.

So, starting at the source ... To help accomplish this outcome you will ideally have pickups that have a strong low noise signal, but don't have an outrageously high and/or distorted output. All the things that many guitarists love, like that crunchy, growly sound with rich harmonics, will simply get in the way when trying to turn guitar notes into a MIDI signal.

This next obvious ramification is No Stomp Boxes (Guitar Effects) in the signal path to the Laptop/PC.
Unless they are being used to 'clean up' or equalise the guitar signal.

For example: A noise gate may prove useful to kill off the guitar signal at very low levels, if there is a lot of background noise. Some equalisation may be useful to balance the signal if you find that certain strings are producing too much or too little output. Some judicious EQ may also help remove unwanted harmonics. Just remember that in this instance Less is Better.

Just F.Y.I. - As of V2.0 Beta, MIDI Guitar has a built-in Noise Gate.

Other things that may make the Guitar to MIDI note tracking more difficult include: Fret Buzz (often the result of lowering the guitar's action ... perhaps a little too aggressively) and noise from your pickup covers or even your guitar lead.

Many of these noises are relatively low in level and can often be overlooked (essentially hidden by an effect called Acoustic Masking) during normal playing, particularly if you are used to using lots of compression and/or distortion. In this case however, ANY extraneous noise is undesirable.

One thing that I have noticed in both MIDI Guitar V1 and V2 Beta, is that my electrified acoustic instruments (Steel and Nylon stringed) work particularly well with MIDI Guitar. The crisp clean tone from the piezo pickups seems to be an excellent sound source.


THE GUITAR to USB INTERFACE

This is probably the simplest part of the entire process. To get a guitar signal into a computer in a usable manner, you will need to buy a Guitar to USB Interface that works with your PC / Laptop and Operating System and install a Low Latency ASIO driver (the ASIO driver should come with the hardware ... but you might want to check before buying).

An example (not a recommendation) is the Behringer Guitar Link UCG102 or similar. It is possible to get Chinese clones of these for under $20 (delivered). You don't need a bucket load of additional / optional software trinkets to install (unless of course you want those anyway). You only need the Guitar to USB Interface device and the Low Latency ASIO driver for this project.

If you are already bringing audio in to a PC/Laptop via a USB device for use in a DAW (or similar) - then you are most likely already set up.

For example: With the AXE-FX III (after installing AXE-Edit), a copy of the unprocessed input signal is available at USB output 5 (by default). That signal can be selected as an input in MIDI guitar - job done.


THE PC or LAPTOP

This is where things get a little more challenging (and potentially expensive). The amount of processing required to identify even a single note, let alone discriminating the notes in a chord, is well ... quite staggering. And in this case, it needs to happen in real-time. So the PC or Laptop needs to have reasonably good CPU speed. Ideally, the faster the better.

There is currently no information regarding the minimum requirements for running the MIDI Guitar software. I can however, definitely say that a 64 bit Laptop with a Dual Core 2.8GHz CPU, 8GB RAM, running Win 7 (without too much crap installed) seems to work well, with the signal preprocessed by a Guitar to USB Interface.

This assessment is based on the reported Buffer requirement of only 49 (apparently quite low), and the indication from the help page that anything below 150 would be considered good. Also CPU usage seems to be consistently low (less than 50%) suggesting the processor has plenty of headroom.

Currently using a well spec'd quad-core laptop under Win 10 with no problems.

There are of course still occasional tracking inaccuracies but it's hard to know whether this is due to my playing, the guitar, the laptop or the MIDI Guitar software. Some experimentation suggests that at least some of my problems are the guitar setup itself ... action is a little too low ;-)


MIDI GUITAR SOFTWARE

The MIDI Guitar software from Jam Origin is what it's all about. By making it possible to interface an electric guitar to essentially any MIDI device such as a keyboard, synthesizer, Software DAW and other MIDI software (via LoopMIDI), a humble electric guitar can become an orchestra.

After some communication with Jam Origin they were a little surprised that I was using MIDI Guitar for live playing. It seems that their primary goal was for MIDI Guitar to be used with Software DAWs, essentially as a Plugin ... interesting.

Installing the MIDI Guitar software is just a matter of copying / decompressing the files from the provided zip file to the folder of your choice. You can then run either the 32bit or 64bit executable from that folder (or create a shortcut to some other location, e.g. your desktop). I suspect that an installation package (setup.exe) will happen at some point.

The free Demo version does have an annoying 'Buy Now' beg screen which reappears every few minutes. This is removed once you purchase the MIDI Guitar program and place your registration file in the same folder.

The program setup is relatively straight forward and mostly a matter of selecting inputs, outputs and a few simple options. Essentially you can be playing guitar synth within minutes. A software MIDI piano is provided for testing and evaluation so you can get started even without an external synthesizer or MIDI sound module attached.

The MIDI Guitar Support Page gets you most of the info you will need for PC, iOS and more.



Update 15/10/2013:
Last night I updated the MIDI Guitar software to the latest Beta 0.9.3 and once again I'm impressed. Issues I noticed with the (over-enthusiastic) pitch bend sensitivity have been addressed and a raft of new goodies added including the start of a MIDI Learn functionality that allows you to assign MIDI input signals to control some of MIDI Guitar's functions.

Since I have a three pedal USB footswitch which sends/emulates Keyboard Strokes (i.e. key codes from a PC/Laptop), I have asked Ole at Jam Origin whether it would be possible to include some Keyboard Shortcuts for the MIDI Guitar interface.

In particular, Octave Up, Octave Down and Pitch Bend On/Off, as I seem to be performing these operations on a regular basis. Having to stop playing and grab a mouse is rather inconvenient when this actions could be done on the fly via the USB footswitches.

Ole seemed to think that these operations might be made to work using MIDI Learn. Unfortunately the MIDI Learn function did not work with/recognise Laptop Keyboard strokes or the USB footswitches ... fingers crossed for some Keyboard Shortcuts in upcoming releases of MIDI Guitar.

On December 17, 2013 MIDI Guitar came out of Beta with the much awaited version 1.0 and an added surprise, being a Beta release of MIDI Bass Guitar.
April 28, 2015 saw the release of MIDI Guitar v2 Beta ... just awesome!!!

Update 2020
Still using it after all these years, even though I have an SY-1000 with GK-3 as well.


MIDI SOUND SOURCE

For your MIDI sound source (Voices/Tones) you could theoretically use any MIDI device (or even software) that you can connect to the PC / Laptop / iPad that you are using to run the MIDI Guitar software. In this case having a Keyboard or Synthesizer that connects via USB MIDI may be an advantage.

Originally I was using the Casio WK-7500 (USB MIDI) and Roland U-220 (DIN MIDI) as a sound sources. This WK-7500 requires a bit of tweaking to set up, but once you know the process (and if you have the WK-7500/WK-7600 set to remember settings at shut-down), it's reasonably straight forward. Setting up a WK-7500 or WK-7600 will be covered later.

Roland U-220 requires virtually no setup apart from connecting a USB to MIDI Cable (the one labelled OUT) to the MIDI In Port. The USB MIDI Cable has a built-in Driver so there is nothing else to install.

One piece of advice (pre Win 10) is; select USB Ports on your PC/Laptop for each device you need to connect and always try to use the same port for that device. It will simplify using the devices and reduce annoying connection failures. I actually purchased a 4 Port USB Hub just to keep all the Guitar/MIDI related USB connections in the one place (and a single USB connection to the laptop). That won't work with all devices - be aware.

Also, if you have a multi-effects pedal (e.g. Zoom G9.2tt) with MIDI and USB I/O, you should be able to use the ASIO driver provided with your unit via a USB connection. Once hooked up, your pedal will simply appear as a drop down Input Option in MIDI Guitar. Make sure however that your pedal has a 'Clean' or bypassed output available to be used with MIDI Guitar. If not you will want a splitter of some sort or at least a Y connector cable.

With a little software trickery (BOME MIDI Translator in this case), program change signals from the Zoom G9.2tt multi-effects console can also be remapped to useful program change commands on the Roland U220. So you can simultaneously change synth patches when you change effects pedal patches via MIDI.


Update Dec 2022
These days I have a Godin xtSA (with built in 13pin circuitry) to drive devices like the SY-1000 and GR55 directly ... and I'm still using MIDI Guitar, rather than plugging in a great long, fat and rigid, 13 pin cable. I then use MIDI Guitar to send MIDI note information straight to a Roland Integra-7 or other synths (e.g. Korg Kronos) mostly for pads.

Things have moved on and the Zoom G9.2tt monster floor pedal now once more lives in a box, replaced by an AXE-FX III. BOME MIDI Translator does any heavy lifting when it comes to complex MIDI programming and routing tasks. But most importantly - I'm not even using a fraction of MIDI Guitar's available capabilities.

Your Comments:

140404 - (Excellent) - As a guitar player who started out with a plywood made Spiegals guitar for $19.95, I thought heaven had arrived when my arsenal included a Fuzz Tone, Wa-Wa and Sustain Pedal combined, and the word midi had something to do with women's fashions. I've been building a modest home studio for two years and last week was introduced to Jam Origin's MIDI Guitar. I love it. It took me five days to get the input-output and the ASIO drivers configured. Had better luck with loopbe1 rather than LoopMIDI, but that could have been me. In short ... for people like myself who struggle everyday with all the tech issues, I really enjoyed reading your comments on MIDI Guitar. It left me with a sense that I'm just scratching the surface of what might be possible with this small piece of software. Thanks for taking the time.

Editor's Note: You are most welcome. As time permits I will try to add some more info on getting MIDI Guitar set up and running. Like most things, once you've got it sorted, it's easy to forget how long you had to mess around to get to that place. But in this case, it is worth it.

131218 - (Excellent) - This was simply great.



Incept Date: Wizard - 130307
Last Updated: 221128