Sonuus G2M guitar to MIDI converter

The Sonuus G2M is a compact guitar-to-MIDI converter imported to the USA by Peterson from a UK manufacturer. It's a small box, approximately 1 x 2 x 3 inches, with jacks on the end for guitar in and through and MIDI out. Four LEDs show operational status (including tuning).

The G2M is powered by a 9V battery. There's no provision for an external power supply. The specs say the unit draws 10ma. Depending upon the unit's cutoff voltage, I'd expect it to run for 50 to 70 hours on an alkaline battery. One of the LEDs is a low-battery indicator. The G2M can supply phantom power to an attached MIDI device. I don't know whether the phantom power is included in the specified 10ma battery drain.

There's a switch next to the input jack to boost the signal for low-output pickups. This is probably not necessary for most guitars, but it's nice to have if you want to use a guitar with underwound pickups. One of the LEDs is a clip indicator. I didn't find the unit to be at all sensitive to clipping. I did notice that I was much more likely to hit the clipping indicator around the middle of the guitar's range. I don't know whether that's a function of the guitar or the unit.

The power LED doubles as a tuner for a guitar in standard tuning. You pluck a string and then tune it until the power indicator blinks as slowly as possible. There's no high/low indication, so you have to start low and bring the string up to pitch. The G2M's tuner feature is not going to replace a great tuner, but it's good enough for the intended purpose.

The G2M converts a single note line played on any electric guitar to a stream of MIDI data that can be used to drive any synthesizer. The nature and quality of the sound is therefore determined by the synthesizer.

The most important thing about a pitch-to-MIDI converter is how well it tracks what you play. There is always some latency, more so on lower notes than on higher notes. Sonuus specs the G2M's latency at 15 to 30 ms. This is the same latency you'd experience due to the speed-of-sound delay when standing 15 to 30 feet from your amp. It is right on the edge of being noticeable for most players. With just a bit of practice you'll find yourself anticipating the note to compensate for the delay.

The G2M tracks well. You have to play cleanly and be careful to mute unplayed strings. The wound strings are a bit trickier than the unwound strings. The pitch detector will often track the changing pitch as you lift your finger from the fretboard. I find it necessary to mute with the picking hand.

The manual offers a number of suggestions for how to adjust your guitar for best tracking. I found the G2M to be remarkably insensitive to pickup choice, volume and tone settings. Picking and muting technique, however, has a profound effect on the G2M's tracking ability.

The G2M is as plug-and-play as a pitch-to-MIDI converter can get. There are no adjustments whatsoever and no unnecessary features. With proper playing technique, the G2M tracks very well.

The only thing that's a bit puzzling is the fixture provided for attachment of a carrying strap (not included). I can't imagine why anyone would want to carry the G2M on a strap around their wrist or neck.

I had a Roland GR-30 about eight years ago. I had to modify a guitar to install the clunky and finicky divided pickup. Apart from comping Hammond organ parts, I never found much use for the GR-30's polyphony. Most of the GR-30 sounds are for monophonic instruments. The Hammond was the only decent polyphonic sound. The GR30's piano, for some reason, didn't track well; the guitar sounds were pathetic.

The G2M's monophonic converter is perfect for 99% of what I want from a guitar synthesizer. I use it to drive a Roland SH-32 for lead sounds and pads.