Starr Labs Ztar Z7S

Fed up with the vagaries of pitch‑to‑MIDI guitar, but don't have time to learn to play a keyboard? The Ztar offers clean, keyboard‑like MIDI from an instrument that guitar players can relate to instantly. Could be just what you need...

San Diego‑based Starr Labs (originally the Starr Switch Company, until 1996) have been making guitar‑like MIDI‑controller instruments since 1992, but somehow it has taken us until now to get our hands on one at Sound On Sound. Taking a radically different approach to the pitch‑to‑MIDI strategy adopted by most of the other pioneers in this field, founder Harvey Starr reasoned that, as MIDI is a key‑based protocol, it made most sense for MIDI guitarists to address it via a set of keys, but with those keys arranged in a pattern that corresponds to a guitar fingerboard. The solution came in the form of the iconic Starr key‑based 'fretboard' that has continued to grace the majority of the company's models over the last 18 years since the Ztar came into being. The keys on a Starr Ztar neck are actually low‑profile, long, narrow buttons arranged in rows, to represent fret positions, and columns, to replicate strings. Pairing the pressure‑sensitive Starr fretboard with a set of triggers for the right hand results in a guitar‑like instrument that outputs clean MIDI with none of the delays and pitch detection errors that plague pitch‑to‑MIDI instruments.

Starr Labs' instruments have always been customisable to a degree, with plenty of options and configurability available to purchasers. Early Ztar models generally had a bank of six elongated switches, or 'Trigger Bars', for the 'picking' hand, as well as a selection of larger pad surfaces suitable for drum triggering, but an option for right‑hand triggers based on six short lengths of real guitar string was soon made available. These are perhaps easier to adapt to, for most guitarists, and also allow notes to be 'damped' in a fairly intuitive way. The strings generate no pitch data (in the basic 'guitar' mode), merely note‑on timing, and velocity. In other modes, however, the strings can also be used to send chords, trigger sequences, or apply Continuous Control messages simultaneous with picking notes. You might, for example, want to be able to add modulation or crossfade between voices via velocity.

Introducing The Z7S

The soft keys around the LCD control the major edit functions and, as pictured here, allow instant recall of complete setups of the entire instrument optimised for different playing styles or MIDI voices.

In recent years the company have expanded their offer to incorporate a wider range of models, including some more entry‑level instruments that replace the switchboard with an all‑in‑one 'fingerboard and frets' combo with virtual strings. The instrument we had on test at SOS was a Z7S model from the Ztar range — a Steinberger‑like, 'non‑bodied' guitar, with a switchboard neck and a maxed‑out set of additional sensors. To begin with, it felt as though whatever I touched on the instrument was transmitting some controller or other, whether I wanted it to or not! Once I'd found out how to turn a few of these off, I was able to establish that the Ztar could indeed transmit very clean, fast, accurate MIDI note data, ideal for programming parts into a MIDI sequencer.

Adapting to the array of buttons where the strings and frets would normally be was surprisingly easy. I had expected my radar to be thrown off by the fact that the 'fret' positions are all the same size, and the octave 'fret' a very long way down the neck, but inside a few minutes it had become simply a non‑issue. The length of travel of the fingerboard buttons is effectively about the same as on a very well set up guitar, so you can get around it very quickly and easily once you've got your bearings.

Surprisingly, the right‑hand string triggers took a little more getting used to. These use short lengths of real guitar string, all of the same gauge, anchored near the neck‑body joint and passing over a damper/bridge assembly down to six locking screws at the base of the body. A tuning screw allows tension adjustment from slack to 'pingy', and seems to be a key element in achieving reliable triggering at the same time as allowing access to a full velocity range. Velocity is read via a piezo pickup, and while stiffer strings allow for a much faster playing response, I found that a slacker setup, to the point of being almost unpitched, produced a much more articulate response in terms of MIDI velocity. The compromise to be reached there will no doubt vary from player to player.

The string triggers can also be used as one of the means for the player to damp notes and stop them sounding. The actual strings will stop vibrating almost immediately, due to the wide, felt‑covered bridge, but there is some kind of capacitive sensing going on that will send a note‑off message when you touch a string that is nominally 'sounding', at the same time as making contact with the conductive metal strip that runs down the centre of the back of the neck. In practice, your left hand is rarely not in contact with the strip when you are playing, so the damping mechanism is extremely intuitive for most players.

The string triggers and the neck switchboard are the two primary systems of the Ztar, but the review model was also fitted with the optional TCA1 Key Trigger assembly — pressure and velocity sensitive rubber bars that can be used instead of the strings — plus another optional sensor running along the entire upper edge of the neck, as well as more standard items like a joystick, control knobs for volume and modulation, and connections for sustain pedal and volume foot controller. Output is via USB (also used to power the instrument) or standard MIDI connector, in which case an external 9V DC 500mA adaptor can be used to 'phantom' power the Ztar via its MIDI input, by means of a (supplied) small interconnect box.

Six trim-pots, accessible through a small slot at the rear of the Ztar, allow you to adjust the individual string‑trigger gains to optimise the response for your fundamental playing style. There are also individual Gain parameter settings within the operating system and the opportunity to select any of 16 different response curves. I settled on a slightly lower sensitivity setting than the calibration point suggested, and a mid‑level curve, reasoning that spurious notes tend to throw you off more than missing ones when recording, especially as you can easily go back and put the missing ones in, but there is more than enough range in all parameters to make a very different choice. One caveat: while the sensitivity pots appear to be conventionally designated, with trigger one under the 'first string' and trigger six under the 'sixth string', they are in fact the other way round: the setting for trigger one relates to the string nearest the top when you are holding the instrument in the playing position, conventionally referred to as the sixth on a real guitar. It is also important to remember this when you are adjusting string‑based parameters within the software, as I singularly failed to do until I realised what was going on.

Keys, Hot & Soft

Connections (left to right): USB (I/O and power), sustain pedal, volume pedal (50k linear, passive, keyboard‑style), MIDI In, MIDI Out and switch to select between the MIDI sockets and MIDI via USB.

The upper edge of the Ztar body, facing the player, features a two‑line, 40‑character backlit LCD display with eight 'softkeys' surrounding it. If you've ever wondered what happened to the membrane switches that adorned music technology products of the late‑'80s, they are still alive and well on the Ztar. In addition, a number of dedicated Hot Keys take care of major functions: Oct Up/Down and Pat(ch) Up/ Down are self‑explanatory (other than that they apply only to the currently selected zone on the fingerboard), while Trig turns the string triggers on so that the Ztar can be played like a guitar, or off to allow the fingerboard to be played directly in a two‑handed 'tapping' style. G/Poly selects between a guitar‑like mode, where only one note can be played per string, and a fully polyphonic mode, where, theoretically, every note on the fingerboard can be sounding at once! Rather more practically, Poly mode will allow you to access piano‑like, tight chord voicings and clusters that would otherwise be impossible.

If that is getting a bit beyond your ambition (or technique), the Rec button offers a useful chord‑recording function that allows you to hold down a chord on the fingerboard and then touch any one of the sensors to assign those notes to it for instant playback. You can then rhythmically 'play' a complex chord sequence without having to actually make all the changes yourself. These chords can also be changed into step sequences by changing the pad setting. Chords or sequences may be looped as well. The on‑board arpeggiator adds another useful 'auto‑play' function to the mix. The 'strings' also all have fully variable tuning capability and, in fact, each key on the fingerboard may actually be tuned independently as well, if you wish. Obviously, this is not so useful with conventional instruments, but comes in handy for grouping related percussion articulations in convenient places, or simulating instruments that include drone elements, or creating diatonic instruments with no 'wrong' notes, or creating custom chord‑maps for the single‑key Chording function...

If your MIDI voice source should start displaying a mind of its own, the Panic button acts in a very functional, layered fashion: the first press sends All Notes Off and Reset All Controllers messages to active channels; a second press sends the same messages to all channels; and a third press 'nukes' everything on every channel, with All Notes Off and all controllers reset to default values. If you've still got a stuck note after that, your software's crashed or you've lost a connection somewhere.

In The Zone

The trim pots, accessed through a slot in the rear of the housing, set the basic gain of the piezo pickups on a per‑string basis. You can then further modify the response in software.

Like any good controller keyboard, the Ztar offers fully customisable splits and layers via its Zoning facility. Up to 32 zones may be active at any time, if your brain can handle it, and a zone can be just a single note if necessary, which you might use to send controller data or a program number without your fingers having to leave the switchboard. Zones may have their own unique MIDI program number and channel, as well as transposition and other performance settings, such as the MIDI controller assignments for the auxiliary sensors and any programmed chords. Setting up a simple set of zones with a bass at the low end, a piano in the middle and a string synth on top is a doddle, as the zone‑definition data can be input directly from the fingerboard.

The Solo button temporarily expands the settings of one of the programmed fingerboard zones across the rest of the keyboard, to let you either quickly change sounds during live performance or just try out a sound over a wider range of notes. You might also use it to set up a held chord or bass note in one zone and then improvise over the top of that by activating Solo in another zone. Using Solo with more than one zone selected gives you a quick way of setting up layered voices.

Once you've got everything as you'd like it, the entire setup of the instrument can be saved to on‑board, battery‑backed RAM via the Write key. What you'll be saving is, in Ztar terminology, a Song, implying that you might use one for each type of song in your live set, or perhaps each general setup of the instrument that you might find yourself working with on a regular basis in the studio. It is apparently advisable to exit Edit mode when playing, as this relieves the operating system of the need to be looking for programming input and therefore makes things a little faster. I have to say I occasionally forgot and found myself wondering why things didn't feel quite as responsive as normal, so it's undoubtedly a good idea. It's also possible, in the edit modes, to accidentally hit the joystick and change something unintentionally.

The primary data-input method might appear to be the membrane switches of the data Inc/Dec buttons, but it's often quicker to use the joystick, which doubles as both performance controller and data‑input source, especially when combined with the Chase feature that allows you to select a parameter to address just by touching it momentarily — for example, you can just play each trigger string in turn and fine‑tune the same parameter for each one via a nudge of the joystick.

Obviously, with no actual strings to bend, pitch bend has to be achieved by other means, just like on a keyboard. The joystick can be assigned like a standard pitch wheel, or you can use thumb contact on the neck strip, which has the benefit of keeping your right hand free, or any of the other data-input sources, although the net result is that it pretty much always sounds like 'keyboard pitch bending'. If really expressive pitch bending is your thing, then pitch‑to‑MIDI is probably still the way to go; you just have to be prepared to live with the other limitations.

It's Complicated...

Unlike a real guitar, the Ztar will allow you to play more than one note per 'string', creating interesting possibilities with combinations of conventional 'fretting' and right‑hand tapping styles.

The Ztar's goal of providing clean, keyboard‑like MIDI from a guitar‑like source is actually more complicated than it may at first appear, even having eliminated pitch detection in favour of fingerboard switches. Keyboards articulate each note from a single source — the key — whereas guitarists articulate notes in two places — the fretting hand and the picking hand. Or at least, they do most of the time... And herein lies the major challenge to the Ztar's designers: the more playable you make the instrument for guitarists, the less keyboard‑like its output potentially becomes. The Ztar, with its left‑hand 'fretting' switches and right‑hand string‑triggers, is actually analogous to using two MIDI keyboards at once, one of which determines the pitch of notes while the other is responsible for Note On messages and velocity data — more complicated than a single keyboard, admittedly, but perfectly workable in terms of producing viable MIDI data. The trouble is, guitarists don't pick every note, particularly when playing any kind of fluid, melodic line. Having had an initial note picked, a real guitar string will often retain enough energy for a couple of different notes to be sounded simply by fretting a different pitch ('hammer‑on') or releasing the string to allow a lower fretted position to sound ('pull‑off'). These are essential guitaristic techniques that must be correctly differentiated from simply pre‑fretting a note in preparation for picking it, if double triggers are to be avoided. And we're not done yet — guitarists also sometimes lightly fret notes under their left‑hand fingers in order to mute them. It would have been easy to allow the desire for 'clean' data to dictate the pragmatic choice of just ignoring all this potential player‑input, but the Ztar's designers are obviously aware that these are the very things that make guitar players feel at home on an instrument, and that familiar and instinctive techniques should, ideally, produce familiar and predictable results.

Delving down the 'Fretboard / Scan‑Mode / Hammers' branch of the menu tree gets you to the heart of the Ztar's adjustments in this critical area for expressive playing. Hammer‑on and Pull‑off can be separately enabled, and 'pull‑off to open strings', can be suppressed to help avoid spurious data when moving between notes. When Hammer‑on is disabled, a light touch on the 'fretted' note will mute it, just like a real guitar, but when Hammer‑on is activated, you have an adjustable parameter to determine the point where refretting an activated 'string' will sound a new note. Set it high and only a heavy hit will generate a hammered note: set it low and only the lightest touch will mute. I found I wanted significantly different settings for different types of playing, dictated by the type of voice I was addressing — the more 'string‑like' the voice (sampled basses and the like), the more left‑hand muting mattered — and decided in the end that this was best dealt with by saving Songs (entire setups) dedicated to different types of playing.

To add further realism to the whole hammer‑on/left‑hand muting simulation, the virtual string will decay over time (at a user‑settable rate), so successive hammer‑ons will get quieter to the point where they will eventually die out, just like the real thing. What happens when you 'pre‑fret' a note with a velocity above the hammer threshold and pick it straight after? You get a double note‑on, of course: the Ztar cannot predict the player's intention, but there is a Mask parameter that delays the sounding of hammered notes to create a window for the picked note to take precedence. It can be set up to work effectively in suppressing double triggers, but, as with most of the parameters, there is a fine balance to be struck between clean MIDI and making the instrument seem less responsive.

The Bottom Line

Enough of the detail; let's get back to the big picture. Does it work? You bet it does... once you've got it set up, once you've adjusted your technique a little and once you've realised what it does well and not so well. Then the Ztar is capable of rewarding you with an immensely satisfying playing experience. In no time at all, I found I wasn't approaching it as a guitar, or even a substitute keyboard, but more as an instrument in its own right and I think that is the best mind‑set to try to get into. Like any 'real' instrument, I suspect it will repay the time spent to really get to know it and I can tell from some of the virtuoso performances on videos scattered around the web that I have only just scratched the surface of what is possible with the Ztar. As a guitar player, I enjoy it for the new musical ideas that it stimulates, or even the recycled ideas that it allows me to express in entirely new ways. As a programmer, I appreciate that it will allow me to play infinite‑sustain parts without using a sustain pedal, so that, just as on a keyboard, I can sustain a high string note and play staccato notes underneath or hold an organ note as a common tone throughout a lengthy chord progression.

Having used or owned just about every guitar‑to‑MIDI instrument that there has ever been since the category existed, this one sits right at the top of the evolutionary path, in my opinion. Its design is based on a fundamentally sound principle and however many layers of additional complication may have been programmed on top of that, you can always get back to that basic principle and find something that works as reliably, predictably and, above all, as fast as a keyboard. It is not perfect: the OS is a bit obscure in places; the USB connector exits the base of the instrument in an area where it is constantly being bumped by the guitar strap (that you absolutely need to wear to make the 'minimal‑body' design stay somewhere sensible when you are playing it!); the membrane switches are, well, membrane switches. But, I have to say, none of that really mattered to me, seeming insignificant compared to what this instrument actually makes possible. Demonstrably, it is not for everyone — about half the guitar players that I asked to try it (all of them involved in recording and production) gave it back after a few minutes and said they couldn't see any serious use for it in their work. The other half, however, all saw it as somewhere between a problem‑solver and a musical revelation. If you are a guitar player for whom MIDI programming or performance is a significant part of your work and your keyboard playing is not so hot, you owe it to yourself to spend some time with a Ztar to find out what it could do for you.