Abbingdon Music Research Compact Disk Processor CD-77 - Manual (Page 31)

31
An S/PDIF link
was not offered
as this method
results in exces-
sive sonic
degradation
3b. DAC Input
It is possible to allow playback of a large library of music to an exceptionally high standard through the CD-77’s
DAC option (See Section 2 item 12 for connection details). Under the DAC mode, the DAC section of the
compact disk processor will disengage from the transport section. Instead, the digital signal from the USB input
(R3) located at the rear of the CD-77 will be used as the music signal source.
It is worth noting that the isosynchronous USB connection used in the CD-77, because of the almost negligible
introduction of jitter, offers a sonic performance that is virtually indistinguishable from CD playback via the
integral transport.
3c. Infra-Red Link
When using the CD-77 as part of a Home Theatre system, it is possible to connect a wireline remote control
cable to the IR link (R4). The CD-77 will become “slaved” to the remote control operation of the Home Theatre
system.
3d. Crowbar ‘Muting’ Circuit
During switch-on and standby/resume operation, the output of the CD-77 is ‘muted’ (turned off) in order to
prevent any audible thumping noises during this period. Unlike the commonly used muting switches or transistors
which are connected in series with the music signal, AMR has employed a relay which shunts across the output
(a crowbar circuit). As a result, the muting circuit is completely removed from the path of the music signal when
not needed yet when engaged, offers complete protection for any equipment connected to the CD-77. Crowbar Muting
Ciruit when not
required, is out of
the signal path