Owner`s manual

CHAPTER 4 -
43
CHAPTER 4 -
Modular Components of the TimewARP 2600
4.14
The Virtual Keyboard
This has  ve octaves, 60 keys. The control panel, at the left, is modeled on
but not identical to the original ARP 3620 keyboard.
4.14.1
Low Frequency Oscillator (LFO) Section
The keyboard unit has its own
LFO
section, independent of any of the standard
VCO’s.
It
can be used in two ways: for vibrato, or for automatically repeated keyboard gates (as, for
example, in imitating the repeated notes of a mandolin). Three sliders govern the
Speed,
Delay,
and
Depth
of the
LFO.
Under MIDI control, the keyboard
LFO
may be synchronized to incoming
MIDI
Beat Clock
signals; see section 4.1.11.4.
4.14.2
Dual-Pitch Control Output
Like the original ARP 2600, the TimewARP 2600 virtual keyboard can generate a second
pitch-control signal when two keys are depressed. This signal is available at the two jacks
labeled
Upper Voice
at the lower left of the keyboard module.
To use one of these, simply patch it to an oscillator. That oscillator will now track the
uppermost key depressed rather than – as with the standard keyboard control signal – the
lower key.
4.14.3
Gate and Trigger Control
Two switches in the upper right quadrant of the keyboard module govern the logic of the
keyboard gate and trigger signals.
When the
Trigger Mode
switch is set to
Off,
the keyboard generates a continuous gate
signal as long as any key is depressed, and generates a trigger signal only on the transition
from no key depressed to any key depressed. In this operating mode, you have complete
performing control over the production of trigger signals; to avoid them, play legato,
and to generate them, play non-legato. This is the baseline logic of the original ARP 2600
keyboard.
With this switch set to
On,
the keyboard will generate a trigger on every new keypress,
regardless of your performing habits. The gate logic is not affected.
The three-position switch labeled
Auto Repeat
is
Auto Repeat isAuto Repeat
Off
in its center position. This is the
Off in its center position. This is the Off
default.
In its lower position, the keyboard gate and trigger are taken from the local
LFO.
Actual
key depressions no longer play a role in gating. In its upper position, the
LFO
and the
keypress are ANDed together; when you press a key, there is a series of pulses from
the
LFO,
and when you release the key, the series stops. This is the mandolin effect we
mentioned above.
The keyboard
Gate
and
Trigger
signals are available on the main panel, from two jacks in
Trigger signals are available on the main panel, from two jacks in Trigger
the
Envelope Generator
section.
Envelope Generator section.Envelope Generator