Some of the performance issues associated with guitar‑to‑MIDI systems may not be insurmountable after all!
Minneapolis‑based Zivix build innovative electronic instruments and related software, including the Jamstik range of ‘guitar‑like’ designs, created with an emphasis on portability and learning. The latest model in the Jamstik range, though, the Jamstik Studio, is very much a real guitar, utilising a Chinese‑made, compact body, headless design from ALP Guitars, and incorporating within it one of the best pitch‑to‑MIDI‑based systems yet made. Yes, you read it right: it’s pitch‑to‑MIDI and it’s really rather good!
Pitch‑to‑MIDI conversion — reading the vibration of strings on a real guitar and endeavouring to convert the pitch and amplitude information to MIDI data — has been at the heart of most MIDI guitar systems that have made it to market in significant numbers. Roland especially deserve an honourable mention simply for sticking at it for decades, and there have been incremental improvements over the years, notably from Axon and latterly the Fishman TriplePlay system.
The inherent limitations of pitch‑to‑MIDI, namely pitch‑variable latency and mis‑tracking, have spawned a number of new approaches to MIDI conversion, from the wired frets of the Zeta Mirror 6, the Sonar detection of the Yamaha G10, through to instruments like the Synthaxe, the Starr Ztar and You Rock Guitar. Some of the latter group actually work quite well as MIDI controllers, mainly because they are not guitars at all, but really ‘keyboards’ whose notes are arranged in a guitar‑like pattern, albeit with the complication of the involvement of secondary triggering with the picking hand.
It seems to me that two distinct groups of people take an interest in MIDI guitars. The first comprises guitar players who simply want to be able to play keyboard sounds from the familiar interface of a guitar. The second consists of those who want to bring some of the expressiveness of their chosen instrument to the world of keyboards, and especially to synths, where you may not be trying to replicate traditional keyboard sounds and playing styles. The two interests are quite distinct, almost to the point of being in conflict.
The former camp, in which I count myself, want the kind of ‘clean MIDI’ that you get from a keyboard, and for which the ‘language’ itself was invented. Note‑On, Note‑Off, Velocity value and a bit of sustain pedal gets you 90 percent of the way there, with a data density that any DAW can handle and any voice module or virtual instrument can understand.
Those in the latter group, however, require something a lot more guitar‑like, with proper strings to bend and apply vibrato to, and to damp with the right hand, using all the instinctive ‘guitaristic’ techniques they normally rely on. In reality, guitar‑to‑MIDI systems don’t actually serve these people particularly well either, and it’s not surprised me to see a growing trend in recent years to bypass MIDI altogether and use digital oscillators and filters acting upon the signal taken directly from the strings; this makes for very playable synthesized sounds, with good tracking and no latency. But it doesn’t get you MIDI and all the advantages it brings in terms of the range and quality of sounds available and the deep editing available in DAW software.
Just when we all thought pitch‑to‑MIDI had nothing substantially new to offer, the MIDI guitar world was shaken up by the arrival of the Jam Origin MIDI Guitar app. This remarkable piece of software utilised the DSP of its computer host to analyse the output from a normal electric guitar signal with all the strings combined into a single audio stream. It wasn’t significantly faster than other pitch‑to‑MIDI systems, in my experience, but it was reasonably clean and accurate, although to many people, still the most remarkable thing was that it worked at all.
It did set my mind to wondering, however: if today’s DSP could now extract MIDI out of the combined waveform of a polyphonic guitar signal, what might it be able to achieve with a hex pickup that gave it each string as a separate signal? Well, that’s rather what I think is going on here in the Jamstik Studio. In this case, the DSP is on board the guitar and because the system is integral, rather than a retro‑fit, the designers benefit from the elimination of a number of possible variables: the exact relationship between the pickup and the strings is known, as are the bridge type, the scale length and the resonance of the body. Having to allow for variation in all of these factors in retro‑fit systems makes a difference to how hard the software has to work just to do the basics, and if it has an easier time doing that, it can devote more power to trying to interpret your playing in meaningful ways. The curious thing about the Jamstik Studio compared with other systems is that there is nothing to adjust in terms of playability parameters — it just works!
The Jamstik Studio guitar has a ‘headless’ configuration with a scaled‑down mahogany body, somewhat like a travel guitar, but it sensibly retains a full 25.5‑inch scale‑length on a 24‑fret, bolt‑on neck that is a familiar 42mm wide at the nut. A pair of covered humbuckers, three‑way selector switch and volume control with ‘pull coil‑tap’ allow it to function as a conventional electric guitar too. It performs that job adequately, if unspectacularly, and that’s not intended as any kind of slur: highly characterful electric guitars don’t make the best MIDI platforms, in my experience. A conventional hex pickup sits behind the bridge humbucker.
Strings are inserted at the nut end of the fingerboard, leading down to the bridge: it’s a slightly odd affair, comprising roller saddles, normally associated with a floating trem bridge, and what looks like thumbwheels for fine‑tuning. I find them a bit too stiff and close together for finger operation, and I guess you are primarily meant to operate them with the mini hex wrench that’s conveniently attached magnetically to the body of the bridge, so you won’t lose it easily.
Given how important accurate tuning is to the performance of MIDI guitar systems, experienced users tend to do rather a lot of it, and whilst every attempt has been made to minimise the potential for slack and slippage in the basic design, the greatest variable of all is temperature. The pitch of steel strings moves over time as they warm up. Just playing the instrument warms them up, so accurate tuning is not a set‑and‑forget activity. The thumbwheel tuners’ gearing is also a bit on the coarse side, I find, so adjusting them with the supplied 20mm right‑angle hex key can be a bit hit and miss. I used a longer key to give me better control, but if there is ever a Mark II of the Jamstik Studio, I hope it has some easier‑to‑use tuners.
As supplied, the guitar was adequately set up, if a little on the conservative side. MIDI guitar setup is a delicate balance of playability versus clean notes for good pitch detection. A higher action will give you a cleaner note with less fret choking, but is more difficult to play, resulting in more ‘release’ noises as you move about the fingerboard, all of which are usually translated as spurious short MIDI notes. The truss rod already had the ideal amount of relief for the supplied .010‑.046 gauge strings, but as the nut is height adjustable, I found it could be lowered a useful amount to achieve a much better playing experience without causing any triggering problems.
Any adjustments at the bridge need to take into account the fixed curvature of the hex pickup. The latter has height and tilt adjustment via a screw at each end, and would, ideally, be positioned with its six pole‑pieces at an identical distance from each string. There are sensitivity settings in the Jamstik Creator software app, but I find it always helps to start from as even a response as possible in the basic setup. Bridge adjustment is not immediately obvious — there are two hex screws in each saddle, like a Strat, but one does the height and the other locks the position after adjustment.
The setup wasn’t ‘wrong’ as supplied, but a bit of basic ‘fettling’, certainly made it more playable in a clean, MIDI‑friendly way. If you make significant changes to the action, you may well find you need to reset the intonation. The saddles are locked in place by a hex bolt that sits directly under the string, which has to be slackened off to access it. Though not ideal, you should only have to do it once unless you change string gauge.
Digital connectivity comprises a USB‑C port, used for both MIDI and charging the onboard battery, with the alternative of a 3.5mm TRS ‘conventional’ MIDI output. There’s also the option of wireless MIDI connectivity using the BLE (Bluetooth Low Energy) protocol. This will add a little more latency to an already very latency‑sensitive activity, so a wired connection is always preferable, but Bluetooth BLE is certainly a convenient option for using Jamstik Studio with iOS and other mobile devices.
Operation via the USB‑C connector requires a data‑enabled USB‑C to USB‑A cable: a ‘USB‑C to C’ charging cable will not transfer MIDI data. The onboard Lithium‑ion rechargeable battery will give in excess of eight hours unconnected playing time, but if you are connected via a powered USB port, you’ll be charging as needed anyway. I must just add, having poked around under the hood, ultimate kudos to Zivix for what looks like a user‑replaceable battery. No rechargeable device should be able to be sold without this possibility, in my opinion.
The USB‑C and mini‑TRS, along with an activation switch/indicator, appear on a small mounting plate on the lower bout. When playing the guitar seated, as I and I suspect many others tend to do when recording MIDI into a DAW, this places the USB‑C connector directly sticking into my right thigh, and I’m sure sustained usage would damage the connector over time. A right‑angle USB‑C adapter made it both more comfortable and, I suspect, in the long term more reliable.
Notably absent from the Jamstik Studio, is the 13‑pin, multichannel analogue output traditionally associated with hex pickups. It is entirely logical, given that the Jamstik Studio is processing the hex pickup signal on board to output MIDI directly, but it does mean you can’t take full advantage of ‘guitar‑synth’ products that can use the string output directly for modelling and harmonic synthesis, like the Roland VG and SY units.
If you are wondering where you set up things like the basic modes of operation (single channel versus multichannel; pitchbend on or off etc.), that’s all in the Jamstik Creator Mac/Windows plug‑in. That’s also where you can adjust individual string sensitivity, MIDI tunings/transpositions and check tuning. It’s also a VST instrument that makes good use of Jamstik Studio’s MPE (MIDI Polyphonic Expression) mode, which is now part of the MIDI spec.
MIDI guitar players have been using a sort of version of MPE for years, with each string on its own channel so that individual pitchbend messages to be transmitted, but the full MPE spec allows for other per‑string real‑time control data, too. When the Jamstik Studio is set to MPE mode, MIDI CC11 data is generated from string amplitude, tracking the envelope of the notes and then mapping that data to the synth voices in the plug‑in. It makes for a very natural ‘guitaristic’ playing experience, as instinctive things like left‑hand lift‑off damping and right‑hand palm muting have a useful effect on the output. Of course, the receiving instrument has to know how to do something useful with CC11 data, so you’ll not find it particularly effective just firing a torrent of MPE data at any of your DAW’s virtual instruments that aren’t set up for it.
Because it has its own DSP on board, outputting MIDI directly, the Jamstik Studio is capable of standalone operation connecting to any MIDI device without a computer or tablet in between. The makers Zivix call it “the first contained MIDI guitar solution available for a mass‑market audience”, although I have a Casio MG510 sitting here as I write that also outputs MIDI directly. I do think Jamstik Studio would be more effective in standalone mode if it had just a little more control of basic functionality on board, specifically a ‘multi/single‑channel’ switch, and pitchbend On/Off. As it is, you’ll still have to dip into the plug‑in for those — personally I’d happily dump the coil‑tap switching in favour of MIDI pitchbend On/Off. The Casio had all of that on board in 1988, and a tuner, too. The Jamstik’s standalone tuning can be taken care of with a clip‑on (most will fit and function perfectly well on the vestigial headstock), or using the guitar quarter‑inch output jack connected to a normal electronic tuner.
When you are using the plug‑in for tuning, you will have to remember to have pitchbend activated as the software will be reading the MIDI output for this function. It has to, of course, because there is no analogue output from the hex pickup as there is with the 13‑pin protocol. You can still use the software to tune in single‑channel mode once you realise that only the top‑E display works for all the strings. Logically, the sensitivity monitor display works in the same way — one for every string in multichannel mode, or all strings in the top‑E window in single‑channel mode. Less logical, to me, is the sensitivity‑adjust sliders being in a different window to the sensitivity display. There’s one for each string and a master slider, and at present, adjusting the master resets all the individual sliders to match. A more logical behaviour would be that, having set your individual string sensitivities, you could then adjust the overall sensitivity up or down just to match the requirements of the synth voice you were addressing, without losing the offsets. Some synth voices benefit from a bit more push, others a bit less, while the individual sensitivities are about string‑to‑string balance, which, once set, you wouldn’t want to change.
Currently, there is no facility for changing the preset pitchbend range parameter in the control software settings, although I understand that is about to be addressed with an update and may well be in place by the time you are reading this. Of course, you can change the setting in the receiving instruments, but they may be already set how you want them to work with existing sources.
The guitar has no onboard sound creation of its own, but the free Jamstik Creator plug‑in does offer up some beautiful synth sounds that really show off the potential benefits of MPE mode. When you launch the plug‑in it suggests that you engage MPE mode for “best performance”. That would certainly be the case for live use, where the possibility of greater physical interaction with the sounds certainly gives an increased sense of control. I wonder, however, if the biggest potential user group for Jamstik Studio may actually be people who just want better, cleaner MIDI for playing keyboard parts in their DAW, and they will neither want nor need to be in MPE mode most of the time. For those people, a simpler control app without the synth would be a more useful thing, addressing mode selection, pitchbend range, tuning and sensitivity setup.
The curious thing about the Jamstik Studio, compared with other systems, is that there is nothing to adjust in terms of playability parameters — it just works!
Basic audio‑to‑MIDI conversion in software is now a well‑established process that works very effectively. ‘Real‑time’ pitch‑to‑MIDI, however, is a considerably greater challenge, and deriving ‘real‑time’ MIDI from guitar playing is another layer of complexity beyond. Leaving aside the fact that what we call ‘real‑time’ here can never actually be real‑time — at least some of the note has to be in the past before you can begin working out what it was — guitars have the complication that notes can be initiated in two different places, and in fact usually are. When you move from one fretted note to another and pick the string to sound it, you will have ‘pre‑fretted’ the new note before your picking hand goes into action. It’s something we all learn very early on as players and never have to think about again. Potentially, that pre‑fretting results in a low‑velocity MIDI note just before the wanted picked note. Of course, that ‘unwanted’ note could potentially be excluded by applying a tiny amount of time‑windowing to see if a low‑velocity note is followed immediately by a picked note of the same pitch, but now we are adding a fraction more time to the conversion process over and above just working out the pitch. And some pre‑fretted notes are actually wanted hammer‑on notes that would never be picked anyway… and is that a hammer‑on modulation of an existing note with pitchbend or an entirely new note? As you can see, it’s complicated, and I have to express my admiration for people who continue to push boundaries in this comparatively narrow field.
There may be a few things about it that I would prefer to have seen addressed in a different way, but Jamstik Studio is still one of the best guitar‑to‑MIDI instruments I have used. It offers fast, accurate MIDI, with less spurious MIDI ‘chaff’ in the output than most other pitch‑to‑MIDI‑based systems on the market today. Oddly, it ‘feels’ faster than it measures, although perceived MIDI‑guitar latency is substantially determined by buffer size and the attack characteristics of the actual synth voice you are addressing. My measured times from pick transient to the start of the converted MIDI note have the top‑E at a rapid 5‑6 ms, with low‑E at around 25‑30 ms. The vagueness in the numbers stems from the fact that my measured times weren’t always consistent, There is perhaps some contextual interpretive ‘intelligence’ in play. The developers are, perhaps understandably, unwilling to reveal anything about their conversion algorithm other than to say that it is new and developed entirely in‑house. Whatever they’ve done, it works, and means that you seem to get more of what you intended and less of what you didn’t, like open strings ringing, lift‑off re‑triggering and the rest of the rubbish that MIDI guitarists have just become used to hunting down and deleting in their piano‑roll editors.
Even for the most experienced MIDI guitarist, the activity has always been a mixture of delight and frustration. Whilst there is still room for improvement, the Jamstik Studio certainly brings me more of the former than the latter, and represents a very worthwhile advance in its field. A full‑size MIDI guitar has apparently “always been a dream of the team of developers at Jamstik. The product we’ve wanted to launch since the beginning”, and I’m delighted they stuck at it!
- Fast, ‘clean’ MIDI output.
- Familiar, real‑guitar format.
- Outputs MIDI directly.
- Jamstik Creator soft‑synth makes good use of MPE mode.
- Works in standalone mode.
- Tuning via hex wrench is a bit of a pain.
- Important control parameters exist only in software.
Combining pitch‑to‑MIDI with powerful onboard DSP has resulted in a worthwhile step forward in performance. This iteration may not be perfect, but I’d still have to rate it as a strong contender for ‘best in class’.