4
5
4
8
9
stereo aux return a inputs
11
, and direct
inputs jacks
13
, that allow you to stack other
sub-mix modules with Ostrawa.
STEREO VS MONO SOURCES
Ostrawa features four stereo pairs of inputs,
which enable mixing up to four stereo sourc-
es. However, monophonic sources may also be
mixed in, as each stereo pair of inputs is in-
ternally normalled so that connecting a mono
signal into the l input correctly places it in
the center of the stereo scene.
VOLUME CONTROL
The signal amplitude in Ostrawa is controlled
using high-quality VCA chips with an expo-
nential response we carefully bent to achieve
the natural fader curve found in professional
studio consoles. The control circuit combines
incoming CV with attenuator settings (fig. 2).
The vol knob generates appropriate offsets
to the incoming CV while retaining the dy-
namic response to CV regardless of the at-
fig. 1
the interface
fig. 2: gain response to knob position
0 1 2 3 4 5 6 7 8 9 10
10
0
-10
-20
-30
-40
-50
-60
-70
5V
10V
8V
Attenuator setting
Gain [dB]
