The Original Voyager Edit
Like the original Mini, the audio circuitry is all analog, but the Voyager adds microprocessor control and with it a host of new functions: patch memory, MIDI, a velocity and aftertouch sensitive keyboard, and a touch pad that can generate three control voltages based on X position, Y position, and a Z value that is proportional to how much surface area is in contact. The envelopes are expanded from the original Model D Mini's three-segment design to a full ADSR configuration (two are provided, with the second one being dedicated to the filter), and a dedicated LFO is provided. (On the original Mini, there was no LFO. One of the three VCOs could be switched to low range, but this left one less VCO for audio signals. An LFO was a widely-wished-for feature, and many of the Model D aftermarket kits provided on.) Expanded modulation routing, compared to the Model D, is also provided, with VCO 1, the mod wheel and the LFO all being routable to a number of control destinations.
The Voyager maintains many of the design cues of the original, including the wooden case, the tilt-up panel, the same type of knobs, and the color-coded rocker switches. Every other feature of the Model D is provided except for the 440 Hz tuning oscillator, which was probably felt to be unnecessary since the Voyager has an auto tune function.
In, Out, and Thru MIDI jacks are provided. The MIDI implements MIDI overflow. Up to 16 Voyagers can be chained and played polyphonically from the keyboard of one unit (or an external MIDI source), with each unit in the chain playing one note in a chord. The touch pad also sends MIDI, as do all of the parameter controls. The patch memory holds 128 patches. The real panel contains CV/Gate input jacks and some jacks to inject control voltages into various functions, an external audio input, and an accessory port. The accessory port can be used to connect VX-351 and VX-352 expansion boxes, which provides a number of additional control voltage and audio outputs and inputs, respectively.
Voyager Variants Edit
Moog has produced many variations of the Voyager; most of these are cosmetic, but there are three significant variants. The Voyager Old School (Voyager OS for short) retains the analog circuitry and controls, but deletes most of the microprocessor-enabled features such as the patch memory, MIDI, and the touch pad. The Voyager RME (Rackmount Edition) was, as the name suggests, an rackmount module lacking a keyboard. The Voyager XL, introduced in 2011, adds a number of patch points on the panel, making the synth a semi-modular. It also includes a second LFO, a full five-octave keyboard, and a built-in ribbon controller. As of late 2011, the Old School is out of production, but the original is still being produced, along with the XL.
The Voyager OS Edit
This model most closely resembled the classic Model D Minimoog, and it provides the closest approximation of the Model D experience available in the Voyager series. It is a strictly analog machine with all of the microprocessor functions removed (which, among other things, means no patch memory). The touchpad is removed, and of course there is no LCD screen and no MIDI. The digital scanning keyboard is replaced with an old-style analog keyboard that uses a resistor ladder to generate the control voltage. The OS is not an exact functional duplicate of the Model D as it does retain the analog features introduced by the original Voyager, including the LFO, the modulation busses, and the ADSR envelopes.
The Voyager OS was introduced in 2008, and discontinued in 2009. Around 200 were built.
The Voyager RME Edit
This was the original Voyager re-packaged in a 19" rack mount chassis. It contains all the features of the original Voyager except for the performance controls (keyboard, pitch/mod wheels, and the touch pad). Some rearrangement of the panel was necessary to get everything to fit within the horizontal dimension of a rack.
The Voyager RME was introduced in 2005 and discontinued in 2015.
The Voyager XL Edit
This version adds a patch panel to the left end of the Voyager panel, transforming the Voyager into a semi-modular synth. The patch panel provides access to input and output points of the synth's components, plus a pair of attentuators, a stand-alone mixer, and a second LFO. SInce the patch panel makes the case wider, the XL comes equipped with a full five-octave, 61-key, C-to-C keyboard. (Other Voyagers have the typical Moog F-to-C keyboard.) The XL also adds a ribbon controller.
The Voyager XL was first offered in 2010. As of mid-2015, the XL is in production and is currently the top of Moog's product line.
Comparison to the Model D Minimoog Edit
Considerable debate exists as to how authentic the Voyager is to the sound and playability of the original Minimoog. Even though the basic circuit designs are similar to the original, Moog took considerable advantage of the advances in circuit miniturization that have occurred since the 1970s in designing the Voyager, and some claim that this harms the sound. However, other performers point out that original Minis are now 30+ years old and that their sound is considerably influenced by component aging and repairs, and anyway, the Voyager is immune from some problems that plagued the original, such as not staying in tune. Despite some dissent, and a rather hefty price tag, the Voyager has sold well and continues to be the mainstay of the "new" Moog's product line.