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Drawmer, D-clock, Chapter 1 – Drawmer DMS-2 D-Clock Clock Measurement & Distribution User Manual

Page 4: Dms-2, Introduction

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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 frequency +/- 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