Voltage Controlled Amplifier
You can think of the Voltage Controlled Amplifier (VCA) as a "gate" to start, stop, and shape the volume of audio or control signals. Applying a simple gate voltage will abruptly open and close the VCA; the CV output of an envelope generator allows shaping of audio and control signals with more finesse.
Initial Gain- Sets the static gain of the amplifier; a good analogy would be opening a faucet. For standard instrument-type sounds, you'll likely leave this set to minimum, and use AR and ADSR envelope generators CV's to control the VCA. Turning up the Initial Gain is useful for "hands-off" droning sounds.
If you're trying to figure out why CA2600 is continuously making noise and won't shut up, the first thing to check is VCA Initial Gain.
Output jack- Audio output of the VCA; this allows routing the signal anywhere desired. The LED next to the jack lights to indicate signal level.
Audio inputs and attenuators- These are the VCA audio input. Although there are only two jack inputs, CA-2600's unlimited mult jacks allow an unlimited number of sources to be routed to the amplifier.
The slider control above each jack is an attenuator, affecting the amount of the normalled source, or if a cable is plugged into the jack, the amount of the signal from the patched source.
Control inputs and attenuators- These are the gain modulation inputs, affecting VCA level. These work additively with the Initial Gain slider setting, it's generally a good idea to turn it down to zero when using mod sources. The slider control above each jack is an attenuator, affecting the amount of the normalled source, or if a cable is plugged into the jack, the amount of the signal from the patched source.
The table below shows the filter's default sources and destinations.
|
MOD SOURCE/AUDIO INPUT NAME |
NORMALLED SOURCE |
NORMALLED DESTINATION |
|---|---|---|
|
VCA/Audio Input - VCF |
filter output |
VCA audio input |
|
VCA/Audio Input - Ring Mod |
ring mod output |
VCA audio input |
|
VCA/Control - ADSR |
ADSR envelope |
VCA amplitude |
|
VCA/Control - AR |
AR envelope |
VCA amplitude |