4
DRAWMER
DMS-2
D-Clock
D-Clock
WORD CLOCK MEASUREMENT
AND DISTRIBUTION AMPLIFIER
Digital audio facilities often require a number of clock
sources, which are used to synchronise outboard proc-
essors to the system clock rate using external clock in-
puts. The Drawmer D-CLock is a dual input, twenty out-
put word clock distributor with a 16 character blue LCD
display providing a high accuracy reference measurement
of the incoming sample rate. It uses a high stability TCXO
(temperature compensated xtal oscillator) along with a
microcontroller to measure the incoming sample rate to
an accuracy of 2ppm and displays the information in three
different formats, actual frequency (to one decimal place),
nominal fre/- ppm error, or nominal frequency plus
percentage of pull up or pull down.
It has both AES/EBU and BNC word clock inputs featur-
ing a zero latency loopthrough output with switchable high
impedance to maintain the correct level of the digital sig-
nal for onward distribution. Sixteen BNC clock outputs
are situated on the rear panel with a further four BNC
clock outputs on the front panel for quick patching to other
digital devices.
CHAPTER 1
The wordclock outputs can be fed from the wordclock in-
put at any sample rate between 32KHz and 768KHz or
derived from an AES11 input or stripped from an AES3
audio signal at any sample rate between 32KHz and
192KHz. Using an audio signal to provide the clock means
even products without a wordclock output such as some
analogue to digital converters, or one of the many mic
pre’s with internal A/D conversion but no word clock out-
put, can be the master wordclock source for the whole
digital studio.
INTRODUCTION
2 in/20 out Clock Measurement and
Distribution Amplifier
Inputs: BNC with zero latency loopthrough
AES with with zero latency loopthrough
Outputs: BNC loopthrough / AES
loopthrough 20 BNC clock outputs - 33
Ohms impedance
3 sample rate measurement LCD modes
accurate to 2ppm
Universal voltage filtered mains power
input
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