Operation Manual

6.64 Polykey 124
The default value of the following parameters is set at construction
• Strength: value of the impact force (value between 0 and 2).
• Stiffness: value of plectrum stiffness (value between 1 and 20000).
6.64 Polykey
The Polykey module reads signal from a MIDI keyboard and is used to create
polyphonic instruments. This module must always be used in combination with a
Polymixer module. A polyphonic patch is created by inserting modules between a
Polykey and a Polymixer module as shown in Figure 70. Tassman will automati-
cally duplicate the modules appearing between the Polykey and Polymixer module
one time for each voice requested during construction in the Polykey module edit
pop-up menu. The outputs of the different voices of the polyphonic patch are mixed
by the Polymixer module. The resulting signal, coming out from the Polymixer
module can then be sent to any other module. The front panel of the different mod-
ules included in a polyphonic section of a patch are only mapped once on the Player.
This means that every voice of the patch is similarly affected by the settings of the front panel con-
trols. Keep in mind that the computational load inevitably increases with the number of voices.
This means that the number of voices that can be played really depends on the complexity of the
patch one is playing and on the computer processing power.
The Polykey module has no input and two outputs which are similar, for every voice, to that of
a Keyboard module. The first output is the gate signal. It is equal to 0 Volt when no key is played,
and 1 Volt when a key is played. The second output signal is the pitch signal. The pitch signal
varies by 1 Volt per octave which implies a change of 1/12 Volt for a pitch variation of 1 semitone.
The pitch signal is calculated with respect to the C3 key (middle C) which outputs a value of 0
Volt. This means that, for example, the C2 key signal is -1 Volt and that of the C4 key is +1 Volt.
The stretch knob on the interface is used to simulate stretched tuning used on instruments such
as pianos. Turned to the left, low notes will be tuned higher and high notes lower (inner stretch);
turned to the right, low notes will be tuned lower and high notes will be higher (outer stretch). In
the center position, the tuning will be equal. The error knob introduces some randomness in the
pitch signal. Turned to the left, no error is outputted and the pitch signal is perfect; as the knob is
turned to the right, errors will start to appear causing small fluctuations in pitch. The effect of this
knob is to simulate pitch variations found in analog synths.
Typical Use
A polyphonic instrument is created by inserting modules between a Polykey and a Polymixer
module as shown in Figure 70. The number of voices is determined during construction.