Plum Audio ARBA Quick Start Manual

PLUM AUDIO – ARBA
Thanks for purchasing ARBA from Plum Audio!
ARBA provides four Voltage Controlled Amplifiers (VCA) with linear response. It may look like a
simple VCA module but under the hood it is packed with features that unleash a variety of uses.
Three features that distinguish ARBA:
•
Normalization: Everything is normalized to everything – all of the inputs, CV inputs and
outputs are normalized between the four channels so you can use a variety of
configurations depending on how you patch it.
As a result of this feature, you can get a significant gain boost (with CV control!) when you
chain several channels together.
•
Variable sensitivity: Unlike most VCA's in Eurorack that clip easily due to the 5V unity gain
– the cause of this annoying clipping is that many envelope generators output a standard
voltage of 8V – with ARBA you can set the sensitivity of each of the channels (or - how
much voltage needs to reach the CV input to get unity gain at the output) using the four
trimmer resistors located on the back of the module.
•
Limiters: soft clipping diodes will limit the outputs to 10.2 volts peak-to-peak and warm
up the sound (the limiters can be disabled using switches on the back of the module).
The combination of these three features allows a variety of uses, for example:
Quad simple linear VCAs
Stereo VCAs
Summing VCAs
Soft clipper
Distortion with CV control
Level booster (instrument or line level to Eurorack level)
And much more...