Drawmer 1962 Digital Vacuum Tube Pre-Amplifier - Manual (Page 10)

1962 OPERATORS’ MANUAL 6
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The LED will illuminate brightly and steadily if a reliable and compatible clock
source is recognised.

The LED will blink when External Clock is selected on the front panel, but no
external clock is detected.
'
The LED will flicker dimly if the clock signal is inadequate due to problems such as
level matching or signal corruption. Typical causes of such problems are: the
connected cable is too long or of an incorrect type; the external clock signal has
deteriorated in quality to a point where it cannot be read reliably.
When External Clock is selected on the front panel, a reconstituted version of the input word
clock is available at the Word Sync Output BNC connector.
DIGITAL DATA
Three digital data output formats are supported by the D62 digital interface.
AES/EBU: via an XLR connector designed to be used with standard balanced
microphone cable (20 metres maximum), wired pin 1 screen, pin 2 and 3
balanced data, and the XLR shell connected to the chassis. Having many
short cables joined together is not advisable as each connector can cause
undesirable signal reflections. The AES/EBU output is enabled when the
Output Select button is in its Out position. The status LED illuminates to
confirm this mode has been selected.
The output socket fully conforms to the EMC standards; if the unit is to be
used where it may be exposed to high levels of disturbance, such as found
close to a TV or radio transmitter, it is suggested that the screen of the data
cable be connected to the chassis connection on the XLR type connector
rather than to pin 1. If ground loop problems are encountered, never
disconnect the mains ground, but instead, try disconnecting the signal screen
on one end of each cable connecting the outputs
S/PDIF: via a high quality RCA type phono jack where the data conforms to the
Sony™ Phillips™ Digital InterFace format. Because this connector only
provides an unbalanced termination, the recommended maximum length for
this cable is 3 metres, even with very high quality cable. This socket is
enabled when the Output Select button is set to its IN position; the status
LED illuminates to confirm selection of this mode.
TDIF: (Where the D62-T is fitted). This is permanently enabled and presents the
digital data in the standard paired formats. If connection is to a Tascam™
DA88 or DA38, we strongly recommend using the Tascam accessory
Dubbing cable PW-88D which is 1metre in length. We have also successfully
used the 5 metres cable PW-88DL, but external interference might make
digital data or timing signals unreliable.