User Guide

dCS Purcell User Manual Manual for Software Issue 2.2x
dCS Ltd September 2004
Manual filename: Purcell Manual v2.2x.doc Page 38 email: [e-mail]
English version web-site: www.dcsltd.co.uk
SPDIF Optical Input
The optical input is used for optically transmitted digital signals with sample
rates up to 48kS/s. In practice, the interfaces are tested up to 96kS/s but dCS
cannot guarantee this with non-dCS source equipment. The data format is
IEC60958, otherwise known as SPDIF.
If fitted, use the Toslink input with Toslink fibre optic cables designed for digital
audio use. If fitted, use the ST input with ST style fibre optic cables. Pull off the
plastic cover before use.
Wordclock Digital Input / Output
WClk In accepts a Wordclock at sample rates up to 96kS/s. It allows Purcell
and your source equipment (e.g. CD or DVD player) to be synchronised to a
master clock. This arrangement helps reduce jitter, which can degrade the
audio output. See WClk on page 25 for more details.
IMPORTANT! If the input and output sample rates are not the same, you cannot synchronise
the DAC (or other equipment driven from Purcell’s outputs) to the master
clock. Slave it to Purcell’s digital outputs or WClk Out instead.
WClk Out is intended to synchronise other equipment to Purcell. It provides a
Wordclock at the sample rate of the AES 1 output, up to 96kS/s. If the selected
Output Mode (see page 25) is Dual AES, WClk Out will run at half the output
sample rate. Purcell must be locked to a source (rather than unlocked,
attempting to lock) for correct operation of this output.
There is no data on the wordclock interface. Use with 75 ohm co-axial cables
designed for digital audio or RF use.
AES/EBU Digital Outputs
The AES 1 and AES 2 outputs may be used individually for digital signals with
sample rates up to 96kS/s. The data format is AES3.
For output sample rates of 88.2 and 96kS/s, the AES 1 and AES 2 outputs may
be used together, but the Output Mode (see page 25) must be set to Dual
AES.
For output sample rates of 176.4 and 192kS/s, the AES 1 and AES 2 outputs
must be used together. Purcell automatically sets the Output Mode to Dual
AES.
Use with 110 ohm screened, twisted pair cable designed for digital audio or RF.
Unscreened cables must not be used as they may pick up interference from
other appliances.
SPDIF Digital Output
The SPDIF output is used individually for digital signals with sample rates up to
96kS/s. The data format is IEC60958, otherwise known as SPDIF. RCA
connectors are the type commonly found consumer equipment.
Use with 75 ohm co-axial cables designed for digital audio or RF use. Some
types of audio cable are not suitable and may cause crackling noises or other
malfunctions.