- Sound Engine
How It Works
The CVC has standard presets for a variety of voltage ranges. These standard presets have the 16 analog outputs on the CVC organized in four groups, each group supplying four analog voltages. Within each group of four outputs, one has an LED on the front panel (the Gate), and the other three outputs are labeled X, Y, and Z on the front panel.
The CVC reports the pressure and position for up to four simultaneous fingers pressing on the continuum playing surface. Each finger uses one group of four outputs: Gate, X, Y, and Z. (If polyphony greater than 4 is required, CVCs can be daisy-chained.) If desired, more extensive and complex setups can be created with the Continuum Editor on the CVC page of the Editor, using the CVC section of the EaganMatrix.
Gate - A finger comes in contact with the playing surface
For each group of four outputs, the Gate indicates that a finger is touching the surface. When no finger is touching the surface, the Gate is inactive. If the Gate is active, the LED above the gate output turns on. The output voltage ranges for the CVC are selectable, but the most common setups have an active gate at 10v, and inactive is 0v. This 10v level is more than enough to trigger analog synth gates, including the 12v Buchla.
Some analog synth patches won't use the Gate at all. Depending on the patch, having Z (pressure) go to 0 between notes is enough to turn off the sound, and there is no need for Gate. The Continuum is continuously sensing pressure, so many sounds do not trigger envelopes and have no need for Gate -- instead, the patch amplitude is just directly controlled by Z (finger pressure).
The Gate output can also be set to have a variable maximum output, set by calculating the velocity of a finger strike on the playing surface.
X Output - The left/right playing position
The X output (next to the Gate) is the pitch (X-position) for the finger. Most setups are configured so that X is 1 volt per octave, with middle C at 0v or at 5v; other configurations (like 1.2 volts per octave for Buchla synthesizers) are also possible. The X output can also take advantage of the myriad of possibilities available through the Continuum's pitch tuning mechanisms, as those settings are echoed to the CVC.
Y Output - The front/back playing position
If the Gate is active, the Y output gives the front-to-back position of the finger on the surface. Often this is set range-wise for -5v if the finger is on the side close to the performer, 0v if it is in the middle, and +5v if the finger is on the side farthest from the performer. These outputs stay at the last respective Y value when the gate goes inactive.
Z Output - The downward playing position
If the Gate is active, the Z output is is the pressure of the finger. Often Z is configured with a range of 0 to 10 volts. When the finger is released, the Z voltage goes to 0v, and the Gate goes to 0v, and the X and Y outputs retain the last values they had when the finger was still down.
You can combine Midi control with control voltage outputs from the CVC. The formula based voltage curves are available as Midi output, for extended control of hybrid analog/digital synthesizers.
If only one finger is pressing on the surface, only one group of Gate,X,Y,Z outputs is used. If two fingers are pressing on the surface, two groups of Gate,X,Y,Z outputs are used. There are alternatives to this, as the Continuum can be configured to control just one Gate,X,Y,Z output by a combination of fingers pressing on the surface. The CVC output assignments can be set to be in playing surface splits as per the Continuum's Midi output assignments (e.g. two voices below middle C and two voices above). As well, the order in which the new notes from the playing surface are assigned to CVC outputs can be LRU (assign the new note to the Least Recently Used voice) or LVN (assign to the Lowest Voice Number).