SaLut
Drezno and Lipsk are the first in series of modules
which constitute The Leibniz Binary Subsystem, a
group of 8-bit signal processing devices offering
comprehensive digital signal manipulation, as well
as audio signal, control voltage, trigger, and gate
generation. Drezno is the input/output front-end
of the system, consisting of an analog–to–digital
converter (ADC) and a digital–to–analog convert-
er (DAC), that alone can be used for manipulating
analog signals and voltages based on their binary
representation (see: ‘Binary Code’ paragraph).
Lipsk (sold separately) is a binary logic processing
expander module that can flip (invert) individual
bits of the digital signal representation.
INStaLLatION
Drezno requires 12hp worth of free space in the eu-
rorack cabinet. The ribbon type power cable must
be plugged into the bus board, paying close atten-
tion to polarity orientation. The red stripe indicates
the negative 12V rail and should align with the dot,
–12V, or red stripe marks on both the unit and
the bus board. The module itself is secured against
reversed power connection, however reversing the
16-pin header
may cause serious damage
to oth-
er components of your system by short-circuiting the
+12V and +5V power rails. There are two connection
headers on the back PCB of Drezno for connecting
Lipsk or more expansion modules to form an out-
in loop (see fig. 3). Lipsk requires 6hp of space, and
must be connected to Drezno (and subsequent ex-
panders) using the 10-pin interconnector cable pro-
vided. Furthermore, Lipsk requires its own power ca-
ble to be connected to the bus board. Both modules
should be fastened by mounting the supplied screws
before powering up. To better understand these de-
vices, we strongly advise the user to read through the
entire manual before using the modules.
bINaRy cODE
Binary code represents voltage values using pat-
terns of binary symbols (bits), each having one of
two possible states: 0 or 1. These bits are organized
into strings in order from most significant bit (b
N-1
)
to least significant bit (b
0
). For example, a 3-bit code
can represent the values 0 (code 000), 1 (code 001),
2 (code 010), 3 (code 011) ... up to 7 (code 111). In
an 8-bit system, there are 256 possible values, from
0 (code 00000000) to 255 (code 11111111). The
most significant bit (b
7
) informs whether the signal
value is in the top or bottom half of the range, and
each subsequent bit describes the value in greater
detail (fig. 4 & 5). In an 8-bit modular synthesis
system, the individual bits are represented as gate
signals (binary 0=0V, binary 1=5V). Hence the in-
coming analog voltage is converted into eight gates.
DREZNO cONtROLS aND OPERatION
Drezno consists of two sections (see fig. 1) that can
act entirely independently or as a linked pair. The
ADC input
1
expects either audio or CV signals.
There are eight ADC gate outputs
2
, represent-
ing each of the eight bits, 7 to 0. The illuminated
gain
3
and offset
4
sliders allow the user to
adapt the range of the signal fed to the A/D con-
verter. The sliders’ respective LEDs indicate signal
amplitude and clipping. The A/D converter chip
expects only positive voltages, so for bipolar input
signals, set the offset slider to the upper position.
The converter is internally clocked at a very high
rate (near 2MHz) which helps to avoid aliasing for
audio rate signals. The adc clock input
5
allows
the user to override the internal clock by freezing
the output code at the rising edge of the input sig-
nal (i.e. gate or trigger). Feeding a pulse wave into
the adc clock allows the user to control the ADC
sampling rate. ADC output activity is indicated by
the corresponding set of eight yellow LEDs
12
.
The DAC section mirrors the ADC section. There are
eight DAC gate inputs
6
, representing each of the
eight bits numbered from 7 to 0. The dac output
7
produces a CV or audio signal based on the input
code. The dac clock input
8
expects gate/trigger
signals and is normalized to the ADC clock via the
ribbon cable connected to the expander sockets on
the back of the module (see fig. 3). Therefore, DAC
clock can be replaced by a clock produced by an ex-
pander module, and it can be overridden by any sig-
nal patched into the panel socket. The DAC section
also features gain
9
and offset
10
sliders which
2
modules
explained