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electronic MUSICIAN


By BobBeauSoleil | November 1, 2001

Although guitar-to-MIDI converters have improved since being introduced in the early '80s, they are still inherently finicky and unpredictable, and the range of MIDI control data they can generate is often limited. At best, conventional guitar controllers represent a set of work-arounds that many electronic musicians, especially guitar players, find less than satisfying. The Starr Labs Ztar represents a giant step forward in the quest for sophisticated real-time MIDI controllers, helping to bring electronic music with subtlety and nuance within reach.

The Ztar's design bears some similarity to the SynthAxe, a guitarlike MIDI controller. Despite a few reported reliability problems, the SynthAxe offered a superior method for translating guitar technique into MIDI control streams. The Ztar incorporates many advances in sensor and large-scale integration technologies that developed in the intervening years. Starr's controller offers dependability, advanced MIDI implementation, and more control options, all for about one quarter of the SynthAxe's original price.

Since entering the market in 1991 (see the Ztar 624-D review in the November 1994 EM), the Ztar has continued to evolve. Starr Labs refined the instrument's design by improving materials and mechanisms, frequently updating the firmware, and adding new features and controller options. The two models' gesture-input functions have a few significant differences (see Fig. 1).


From a construction standpoint, the Ztar has little in common with traditional guitars. It doesn't even have strings, in the conventional sense. Its radical design is the root of its success as a MIDI controller.

The Ztar exhibits none of the quirks that have long plagued guitar controllers, such as tracking delays, pitch flutter, false notes, and erratic triggering. Instead of translating string vibrations into MIDI data, the Ztar employs an array of specially designed potentiometers, switches, and sensors, providing a far more direct connection between the player's input and its conversion to MIDI data. Starr's controllers respond to touch with an almost startling immediacy. They translate a variety of gestures into a comprehensive and flexible stream of MIDI control data with predictable precision.

The Ztar is neither a guitar nor a replacement for one. If you approach the device expecting to play it in exactly the same fashion you would a guitar, you probably will be disappointed. On the other hand, if you approach the Ztar with some understanding of the concepts behind its design and of its strengths and weaknesses, you will be rewarded with extraordinary creative and expressive possibilities.

Essentially, the Ztar is a sophisticated keyboard remodeled to mimic a guitar's shape and much of its playability. Its controls let guitar fingerings initiate notes, and they provide techniques for articulation and modulation, including finger pressure, breath, and foot control. In addition, the Z1 has a bank of Velocity- and Pressure-sensitive trigger pads, and the Z1-S has string triggers to facilitate picking techniques.

You can program the Ztar's controls to perform more than one task and to transmit corresponding MIDI messages on several channels simultaneously. The instrument supports user-programmable transposition, alternate tunings, and multiple splits and layering.

Aside from guitarists and bassists, percussionists who want to step out from behind the kit should try the Z1. The Ztar might also be attractive to remixers, sound designers, Foley artists, or anyone who can benefit from a controller with such advanced MIDI implementation.


The Ztar arrives in a well-padded, plush-lined canvas gig bag. An accessory pouch contains a pair of MIDI cables, a wall-wart AC adapter, a 32-page manual, and a black metal junction box for routing MIDI signals and supplying power to the Ztar. A flexible 30-inch plastic tube with a mouthpiece for the optional Breath Controller ($130) input was included with the unit supplied for review.

Like an electric guitar, the Ztar is composed of a body and a neck-and-fingerboard assembly. The neck fits snugly into a notch on the upper body and is fastened with three bolts, forming a solid and ergonomically functional neck-to-body joint.

The housings for the body and neck assemblies are castings of a black resin compound. The body has an attractive, finely pebbled matte finish, and the neck's glossy veneer facilitates easy sliding of the hand against the neck's back and sides. Replacing the wood used in earlier Ztar designs with the cast resin material makes the units less likely to contract and expand with atmospheric changes. A tendency to flex or warp would have compromised the tolerance of the tiny touch-sensitive components, resulting in erratic performance.

Designing a stringless, touch-sensitive instrument that feels good and works well is a challenge for anyone, and Starr Labs' design succeeds. After many years of playing guitars with real strings, I found the Ztar's virtual strings to be a bit of a struggle at first. Within a surprisingly short time, though, I was comfortable playing chords and scales and generally riffing around on the Ztar's fingerboard.


The fingerboard features a 24-by-6 matrix of tiny oblong buttons — the equivalent of the fret positions on a guitar's fingerboard (see Fig. 2). The surface of each 3/32-inch-by-¾-inch Velocity- and Pressure-sensitive button is smoothly rounded. Buttons are black or white, are arranged in a pattern imitating guitar fingerboard positions, and are activated by a light touch. Dot-inlay position markers are on the side of the neck.

When playing a Ztar for the first time, those accustomed to guitar fingerboard spacing should expect a brief adjustment period; the semitone intervals are spaced an equal distance apart. Instead of tapering in the manner of a guitar neck, the Ztar's neck is 23/16 inches wide along its 22-inch length.

The Ztar's fingerboard supports Polyphonic Aftertouch, which provides dynamic expression of notes (assuming your synth supports it) in response to finger pressure applied to keys. The Zone/EFX submenu lets you adjust the threshold and sensitivity of the Pressure response. You can also defeat the fingerboard's Velocity sensitivity, leaving the picking hand to perform dynamic expression with the triggers on the body.

The optional Pressure-sensitive Neck Strip Sensor ($95) is well worth the extra cost. It is affixed to the side of the neck nearest the player's view, partly obscuring the dot-inlay position markers and extending the length of the neck. Controlled with the thumb of the fingerboard hand, the Neck Strip Sensor can transmit Channel Pressure, Pitch Bend, Expression, Sustain Pedal, and other MIDI continuous controller messages.


The Ztar body assembly is molded into a wedgelike trapezoidal shape that is gently rounded at the bottom, is symmetrically sloped at the sides, and terminates in the contoured point at which it joins the neck. With a depth of 2¾ inches, the body is about half as thick as that of an average solid-body electric guitar. The slope of the side panel on the body's opposing side gives the instrument a tendency to slide off your knee unless you hold it at a slightly awkward angle. The shape is less than ideal for playing the controller while seated, but Starr offers an optional knee rest ($35) to remedy the problem. Fortunately, the instrument balances perfectly when used with a guitar strap.

The 80-character backlit display is positioned in plain view on the sloping side of the body (see Fig. 3). The display and its surrounding soft buttons offer access to configuration presets, tunings, controller assignments, operation modes, MIDI status, and so forth.

Most physical controllers are on the top of the body. Each of the six virtual strings connects to a dedicated trigger mechanism on the Ztar's body and operates independently of the others. When you activate a trigger, it samples its corresponding virtual string to determine the correct pitch and transmits the appropriate MIDI control data. In other words, select notes with the fretting hand and trigger them with the picking hand, as you would on a guitar.

The six triggers are just below the fingerboard and aligned on the same axis. Their location and orientation on the Ztar's body will seem familiar to guitar and bass players immediately. Alternative operation modes let you play the fingerboard with both hands by disengaging the triggers from their relationship with the fingerboard.

The Z1's six triggers are elongated membrane-type keypads in a raised-relief pattern to provide tactile feedback. They are Velocity- and Pressure-sensitive and respond equally well to tapping and strumming techniques. Below the triggers are 12 rectangular button-type pads in two columns extending down the center of the body; they also respond to Velocity and Aftertouch. The pads can send controller messages on as many as eight MIDI channels at the same time.

In place of the Z1's keypad triggers, the Z1-S provides six short metal strings stretched between the pickup bridge (just below the fingerboard) and the metal termination bridge (at the bottom of the body). Those strings respond with excellent Velocity sensitivity. For notes triggered from the strings, you can mute them in a natural manner by touching the string with a finger or by touching the metal bridge with the heel of your hand, both of which send Note Off commands. Muting is independent for each string. That makes the Z1-S a good choice for traditional flatpicking, fingerpicking, and strumming techniques.

It's difficult to implement Pressure sensitivity in a triggering system of that type, which gives the Z1 model an edge. The Z1-S forgoes the Z1's pads to make room for its larger string-trigger assembly. However, an optional over-bridge assembly ($340) offers six pads mounted above the string triggers.

In all other respects, the features of the Z1 and Z1-S are the same. On the surface closest to the player's point of view is a row of ten membrane switches serving as function keys. (I normally prefer buttons to membrane switches, but because membrane switches require a more deliberate touch, they help prevent the player from accidentally switching modes.) From left to right, the switches offer Octave Up, Octave Down, Patch Up, Patch Down, Triggers, Guitar/Poly, Solo, Write, Record, and Panic. Switches that perform toggle functions are equipped with small LEDs to indicate their status.

Opposite the function keys and just beyond the triggers are a rotary knob and a joystick. The knob is fully programmable and assignable to MIDI commands suited to rotary control. Likewise, the spring-loaded joystick offers four general-purpose controllers and an additional button feature. Each joystick quadrant (up, down, left, and right) is individually programmable, and pressing inward on the joystick activates a momentary switch that can initiate a CC. Think of the joystick as a sort of super whammy bar for generating out-of-this-world modulation effects (see Fig. 4).

A metal jack plate on the body's lower end sports a rocker power switch, MIDI In and Out ports, a ¼-inch sustain-pedal input, and a ¼-inch volume-pedal input. You can assign the pedal inputs to a variety of MIDI functions. One of the units came fitted with a special connector for the freely assignable Breath Controller's plastic tube. Surprisingly, the jack plate has no legend, so you will need to consult the manual or employ trial and error to determine each jack's purpose. That is an unnecessary annoyance rather than a serious problem.

The sturdy PB-1 junction box connects to the Ztar by means of a standard MIDI cable. The supplied AC adapter connects to a jack on one end of the box, and an LED on the other end indicates when it receives power. A cable from the Ztar's MIDI Out connects to the Controller input on the junction box, and a second MIDI cable connects between the PB-1's MIDI Out and the sound source's MIDI In. That is a less-than-elegant solution to the problem of supplying power to a remote, strap-on controller.


The Ztar is always in Live or Edit mode. In Live mode, the front-panel Record button lets you assign notes to sensors on the fly. First, play the desired notes on the fingerboard; press Record; then, touch the sensor to which you want to assign the notes. Recording even copies to the sensor the fingerboard's MIDI channel assignments for the selected notes. A Chord Hold function operates in a toggle fashion in which the triggered notes sustain until the sensor is touched again; otherwise, you can sustain notes and retrigger them with a subsequent touch.

Interestingly, notes that sound from unfretted triggers are tuned independently of the fingerboard zones — a feature with some remarkable creative potential. Although you can set notes triggered on the fingerboard to standard tuning, you can program the open “strings” for alternate tunings. Furthermore, you can use the open-note tunings as an electronic capo. That feature, in combination with hammer-on techniques, is almost like having an extra digit, allowing for complex fingerings.

The Triggers and Scan parameters determine some of the Ztar's most essential operating modes. The possible settings are Triggers: On/Off and Scan: Guitar/Polyphonic, with each combination resulting in a unique operation mode. Dedicated front-panel function buttons labeled Trig and G/Poly let the player switch between operating modes in Live mode.

When the Triggers parameter is toggled to off, the triggers and fingerboard operate independently of one another. You can play the fingerboard with both hands or play it with one hand while manipulating the sensors on the body with the other. With the Scan parameter switched to Polyphonic mode, you can play as many notes on the fingerboard as your fingers can handle, even if the notes are on the same virtual string.

With Guitar mode activated and the triggers turned on, the Ztar behaves like a traditional guitar: notes selected on the fingerboard are transmitted only when the corresponding triggers are activated with the other hand. If you turn the triggers off while the Ztar is in Guitar mode, you can trigger notes again directly from the fingerboard, but the highest-note priority is maintained. When you select Guitar mode from within the Scan-Mode submenu, additional parameters enable or defeat hammer-on articulations and allow adjustment of hammer-on threshold sensitivity.

If you turn the triggers off in Guitar mode, you can play notes and chords on the fingerboard with one hand. That leaves the other hand free to move the joystick or manipulate other sensors on the instrument's body. Guitar mode also lets you use both hands for tapping on the fingerboard.

The Ztar shines the most in Polyphonic mode with the triggers on the body turned off. You can use both hands to play chords with intervals that would require two keyboard players to perform. Using that technique with alternate tunings can extend the Ztar's range of chording possibilities considerably.

The Ztar does not possess a guitar's facilities for creating pitch bends and vibrato by manipulating strings on a fretboard. The finger-pressure response of the Z1's key triggers is well suited to LFO modulation, so I often employ that setup for vibrato. Generally, I use the Neck Strip Sensor for bending notes, manipulating it with the thumb of my fingerboard hand; alternatively, I use the Breath Controller for supple control of Pitch Bend. For whammy-bar effects, I assign Bend Down and Bend Up to opposing joystick quadrants. You can do some wicked dive-bombing with such a setup, bending notes and chords over any range your synth will allow. With a multitimbral instrument, that technique can produce utterly awe-inspiring sounds.


It's difficult to gripe much about the Ztar. Except for its inability to translate typical stringed-instrument pitch-bending techniques, the Ztar succeeds in almost every respect.

My main criticisms concern the I/O connection scheme. I just can't abide three cables hanging from the end of the Ztar's body. A more elegant solution would provide a floor unit that connects to the Ztar with control pedals already mounted and with a single cable and a built-in power supply (thus eliminating the wall wart). It would also be helpful if the floor unit were equipped with an array of footswitches for sending multichannel Program Changes; that would free the performance sensors from relatively mundane tasks.

Easily, the package's weakest element is the documentation. The loop-bound manual consists of a somewhat loose collection of entries covering various Ztar models, including some that are no longer in production, and the information is not indexed. According to Starr Labs, a new manual is in the works. Meanwhile, you can find a wealth of useful information and novel ideas for Ztar applications at Harvey Starr occasionally haunts the site to answer questions, offer suggestions, and gather ideas for design improvements.

A few minor complaints notwithstanding, the Z1 and Z1-S models are well conceived, solidly built, and extremely versatile. The Ztar's MIDI implementation is unrivaled by any other MIDI controller. Much of the instrument's beauty is its high degree of customization. In fact, it's improbable that any two Ztar players will ever sound the same.

Paired with synths that offer enough modulation routings to do it justice, the Starr Labs Ztar can provide real-time musical-performance capabilities of tremendous depth and power. If you're the adventurous type and your leanings are toward electronic music's frontiers, see what a Ztar can do for you.

Bobby BeauSoleil is an electronic musician and sound designer who has composed for film and video. You can hear examples of his music, including Ztar performances, at


Starr Labs
Ztar Z1 MIDI controller
Z1-S MIDI controller



PROS: Well designed. Durably constructed. Comprehensive and flexible MIDI implementation. Sensors are responsive to the touch. Translates most traditional guitar-playing techniques. Can be customized by programming to accommodate unique playing styles.

CONS: Poor documentation. Cannot translate stringed-instrument note-bending techniques. No legends for input and output connections on instrument body. Cumbersome pedal-connection scheme.


Starr Labs
tel. (619) 233-6715

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