Expert Sleepers Silent Way v1.7.3 - Manual (Page 43)

new instance) which is put in ‘Decoder’ mode. The output of this plug-in is the desired
CV.
Note that the Generator level (see below) defaults to zero so you need to turn it up before
anything will happen. The reason for this is to avoid situations where you might acciden-
tally feed the generated signal out to your speakers and cause damage to your
equipment/hearing/sanity.
Unipolar/Bipolar Operation
CVs can be unipolar - i.e. they take positive values only e.g. 0V-10V - or they
can be bipolar - i.e. they can take both positive and negative values.
Most VCA designs can only handle unipolar CVs. If you want to use Silent
Way CV Input to process bipolar CVs, you have two options:
• use hardware modules to scale and bias your CV into a unipolar range (see e.g. the
Doepfer A-183-2 Offset-Generator/Attenuator/Polarizer module).
• use a four quadrant multiplier VCA. These are sometimes known as polarizing VCAs
or ring modulators, though the latter is really a misnomer. See e.g. the Doepfer A-133
Dual Voltage Controlled Polarizer or the Cwejman VCO-2RM. NB if the device in
question is described as a ring modulator it should be described as ‘DC coupled’ if
it’s to work with Silent Way CV Input.
If you’re using a four quadrant multiplier, switch the Decoder plug-in to Bipolar mode (i.e.
press the button marked ‘Bipolar’). Note that on some systems the output of the plug-in in
Bipolar mode may be inverted from what you expect - if this is the case, use the ‘Scale’
control to invert the output signal.
Controls
The Generator/Decoder drop-down menu separates the controls for each
channel into two parts, those to the left and right of the menu respectively.
To the left of the menu is the one knob that applies in Generator mode - the
‘Level’ knob. This simply sets the level of the generated signal. As mentioned
above it defaults to zero and must be turned up for anything useful to happen.
To the right of the menu are the controls that apply in De-
coder mode. The ‘Bipolar’ button puts the Decoder into
Bipolar mode, as discussed above. The ‘Scale’ knob is a
simple multiplier on the CV. It can take negative values in
order to invert the signal.