Xaoc Devices ROSTOCK Operator's Manual page 5

cells and is delivered to the output after 48
cycles of the clock. In other words, the data is
digitally (and losslessly) delayed.
The physical delay is a product of the clock pe-
riod and the length of the pipeline. For exam-
ple, with a 2MHz clock, it can vary from 0.5us to
32us (inaudible, video rate range); while with
a 5kHz clock it can vary from 0.2ms to 12.8ms
(very short audio rate range); and with a 10Hz
clock it will be 100ms to 6.4s (rhythm and LFO
range).
Varying the length changes the number of
memory cells used. Changing the length while
a signal is being processed yields some idio-
syncratic digital distortion. To understand this
distortion, you need to understand the internal
structure of the pipeline (fig. 2).
The delay length selects a combination of
memory blocks offering 32 stages, 16 stages,
8 stages, 4 stages, 2 stages, and 1 stage, plus
there is one fixed 1-stage cell so that the de-
lay is never 0. While the input data always
passes through all blocks, some blocks are
omitted in the current pipeline by insert-
ing the input data directly into some later
blocks. For example, when the length is set
select
8
stages stages
select
4 2
stages
to 33, the delay consists of a 32-stage block,
and the remaining blocks are skipped, ex-
cept for the last fixed single stage. When the
length is changed to 32, the 32-stage block
is skipped, and the 16, 8, 4, 2, and 1-stage
blocks are used. These, combined with the
last fixed 1-stage block, offer the required 32.
Note that such switching (only by 1) yields
significant data shuffling in the memory and,
sometimes, an interesting glitch.
LOOPING & SCRAMBLING
When the loop button is unlit, the device op-
erates as a straightforward delay: new data
from the Leibniz in is written to the shift reg-
ister at each rising edge of the clock, it is de-
layed by the number of clock pulses set with
the encoder and shown on the display, and it
is passed to the Leibniz out.
With the loop function activated (by press-
ing the button or plugging a 5V gate into the
loop control input jack), the output data
from the pipeline is fed back to the input.
This function allows you to catch a sequence
of data representing, e.g., one cycle of a
waveform or a drum pattern and repeat it as
long as needed.
select
1
stage
fig. 2: the structure of the pipeline in rostock
5
select
1
stage