This is some info on the Yamaha VL1.  It differs slightly from the VL1-m
in that the VL1-m is the rack-mount module with no keyboard, and no front
panel sliders.  Also, on its back, there are only MIDI in/out/thru, power in,
and left/right 1/4" line level outs.
  
----------------------------------------------------------------------------

The Yamaha VL1 Virtual Acoustic Synthesizer produces sound in an entirely new
way. It has no oscillators or function generators,no preset waveforms or
samples. In fact,it uses none of the sound generating concepts employed in
conventional synthesizers. The VL1 represents the world's first practical
application of computer based "physical modeling" in musical sound synthesis,
generating sound using the same principles as acoustic instruments,but with
far more versatility and creative power.
 
The Yamaha VL1 is the most musical synthesizer ever made. A soloists dream!
 
What Are the Advantages?
========================
The VL 1 offers many advantages in terms of musical performance. Not just
in terms of sound, but also in terms of the "behavior" that makes acoustic
instruments so "musical".  The physical model can be programmed to have
certain attributes--the length of a pipe or the stiffness of a reed,for
example--but the actual sound produced by any configuration can only be 
accurately determined by playing it.  Because of its natural acoustic
behavior the VLl is undoubtedly a little harder to play than conventional
synthesizers, but when mastered this is the very characteristic that is
its greatest strength.
 
The VLl sounds better, has more depth, and is more realistic in the musical
sense than any other synthesizer system.
 
Simply pressing a key in the same way does not always produce precisely the
same sound. The instrument is responsive and "alive".
 
Note-to-note transitions have the same continuity exhibited by acoustic
Instruments.  What goes on in between the notes is just as important
musically as the notes themselves.
 
It has extraordinary expressive capability. Rather than simply controlling
parameters like volume or pitch, you can control characteristics such as
breath and reed pressure with appropriate complex effects on the timbre
of the sound.
 
In addition to super-realistic simulations of existing acoustic instruments,
the VLl can produce totally new "acoustic" voices and hybrids which can
vastly expand the players expressive scope.
 
The VLl Model 
=============
The overall VLl model or "algorithm" consists two "elements", each including 
three main blocks: the instrument,controllers,and modifiers.
The two elements actually function as independent tone generators,so although
it is basically a monophonic solo instrument the VLl can produce two 
notes at once. The two elements can also be used as layers of a single voice.
 
The Instrument
==============
The key block in this algorithm is the instrument, since it is here that the
fundamental tone or "timbre" of the sound is defined. Various instruments 
for the VLl are provided in the form of pre-programmed voices--primarily 
woodwind, brass, and string voices, since the VLl's physical model is 
capable of most accurately simulating the sound generating mechanism of 
these three instrument categories. Internally the instrument model consists
primarily of a driver--the reed/mouthpiece,lip/mouthpiece,or bow/string 
system--and a resonant system corresponding to the tube and air column or
string. One of the main differences between the VLl and an acoustic 
instrument is that just about any driver can be used with any type of pipe
or string, resulting in totally new instruments with "acoustic" properties
and expressive power.
 
The Controllers
===============
The input to an acoustic wind instrument comes from the player's lungs,
trachea,oral cavity,and lips. In a string instrument it comes from the
players arm movement,transmitted to the string via a bow. These elements
actually form an important part of the sound generating system and,in the
VLl model,are simulated in the controllers block. In essence the controller
parameters, listed below,determine how the instrument "plays". All of these
parameters can be assigned to any of the external controllers that can be 
used with the VLl: the breath controller,foot controller,modulation wheels,
etc.
 
Pressure: The amount of breath pressure applied to a reed or mouthpiece, or
the speed of the bow applied to a string.
 
Embouchure: The tightness of the lips against the reed or against each other. 
In a string instrument voice Embouchure corresponds to how strongly the 
bow is pressed against the string.
 
Pitch: Changes the length of the air column or the string,and thereby the 
pitch of the sound.
 
Vibrato: Vibrato can be applied via the Pitch or Embouchure parameters for
exceptionally natural vibrato effects.
 
Tonguing: Simulates the half-tonguing technique used by saxophone players by
damping of the reed.
 
Amplitude: Controls the volume of the sound without varying timbre.
 
Scream: Drives the entire system into chaotic oscillation, creating effects 
that can only be achieved with physical modeling technology.
 
Breath Noise: Adds breath noise. The sound of the breath noise itself can be
varied over a wide range.
 
Growl: A periodic pressure modulation which produces the "growl" effect often
heard in wind instruments.
 
Throat Formant: Controls the characteristics of the simulated player's lungs,
trachea, and oral cavity.
 
Dynamic Filter: Controls the cutoff frequency of the Dynamic Filter in 
the VLl Modifiers block.
 
Harmonic Enhancer: Controls the depth of the Harmonic Enhancer in the VLl 
Modifiers block.
 
Damping: Simulates the effect of damping due to losses within the body of 
a wind instrument or in a string due to air friction.
 
Absorption: Simulates the effect of high-frequency loss at the end of the 
air column or string.
 
The Modifiers
=============
Although you don't have direct programming access to the VLl instrument 
block, the modifiers allow a significant degree of control over the final
timbre of the voice. The modifiers block consists of 5 sections,listed below.
 
Harmonic Enhancer: The Harmonic Enhancer allows you to manipulate the
harmonic structure of the sound to the extent that you can create radical 
timbral variations within the current instrument families (e.g. saxes).
 
Dynamic Filter: The dynamic filter has selectable high-pass,bandpass,band
elimination,and low-pass modes,and a "wet/dry" balance parameter which allows
delicate variations in the degree of filtration applied.
 
Frequency Equalizer: This is a 5-band parametric equalizer with frequency,Q
(bandwidth),and level control. The equalizer also has pre EQ high and low
pass filters as well as key scaling capability for precise response control 
throughout the instruments range.
 
Impulse Expander: The Impulse Expander works in conjunction with the Resonator
described below,to simulate the effect of an instruments resonant cavity or 
sound box. It can also be used to simulate the acoustic environment in which 
the instrument is played.
 
Resonator: While the Impulse Expander and even the Harmonic Enhancer tend to
give the sound a metallic quality the Resonator produces a more woody 
resonance effect.
 
There's More ...
In this brief introduction to the VLl we've only looked at the central
physical model which is the key to the VLl's unprecedented sound and musical 
performance. There's actually much more to it. The VLl has an extensive range 
of other functions and features that are similar to those you may be familiar
with from conventional synthesizers. And. of course, there's a comprehensive 
selection of MIDI,disk,and other utility functions that give the VLl maximum 
versatility and convenience. For luxurious looks and feel the VLl even has
beautiful claro walnut top and rear panels,aptly complementing the advanced 
technology inside.

Specifications
============== 
Tone Generator
 TYPE
  S/VA (Self-Oscillating Virtual Acoustic Synthesis).
 MODIFIERS
  Harmonic Enhancer
  Dynamic Filter (LPF,HPF,BPF,BEF,with resonance).
  Equalizer (5 bands with frequency,resonance,and boost/cut control).
  Resonator.
 EFFECTS
  32-bit digital signal processor,stereo in/stereo out.
  Modulation effects (flanger,pitch change,distortion).
  Reverberation.
 PLAY MODE
  Voice mode only
  Smallest tone generator units: elements. Voices use 1 or 2 elements. Voices
  are composed on "common data" and "element data".
 POLYPHONY
  2 notes max.
 ASSIGN MODES
  Mono,Poly,Unison
 
Memory
  Internal: 128 voices.
  Disk: 3.5" 2DD or 2HD floppy disk.
 
Keyboard
  Keys: 49 (C scale,FS type).
  Sensitivity: Velocity. Channel aftertouch.
 
Controllers
  Master volume slider. Modulation wheel x 2.
  Continuous sliders x 2. Data entry dial.
  Pitch bend wheel. LCD contrast control.
 
Panel Switches
  Play (with LED). Program change x 16 (with LEDs) Edit (with LED). Data 
  entry x 2.
  Utility (with LED). Cursor x 4
  Octave x 2 (with LEDs). Function x 8
  Copy. Exit. Store. Enter. Bankselect x 8 (with LEDs).
 
Display
  240 x 64 dot liquid crystal display (black and white type) with fluorescent
  (CFL) backlight.
 
Connectors
  Front Panel: Stereo headphones.
               Breath controller
  Rear Panel: Output x 2 (L and R).
              Foot controller x 2
              Foot switch x 2
              MIDI IN.
              MIDI OUT.
              MIDI THRU
 
Output Level
  Line: 2.5 + or - 2 dBm Into 10 kOhms.
  Headphones:7.5 + or - 2 dBm into 150 Ohms.
 
Power Requirements
  US model:      120V,16W
  General model:   220...240V,16W
 
General
  Dimensions (W x D x H)
  914mm x 380mm x 105mm (36" x 14-7/8" x 4-1/8")
  Weight:12.5 kg (27.6 lbs.)
 
Accessories
  Power cable.
  BC2 Breath Controller.
  FC7 Foot Controller.
  Floppy disk.

           [ All specifications subject to change without notice. ]