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dCS 954 User Manual Manual for Standard Software Version 1.5x
dCS Ltd June 2000
Manual part no: DOC136954 iss 2B1
Page 26
file 135954ma2b1.pdf available from website
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I-For -
(Input Format). Sets the AES input multi-wire format Input Format. There are 4
options:
Auto The message flags on the selected input are
checked and the format is automatically set to
Single, Dual or Quad AES. Dual AES must be
connected to AES 1 & 2 or AES 3 & 4.
US[1] User-selected Single AES mode.
US[2] User-selected Dual AES mode.
US[4] User selected Quad AES mode.
You can over-ride any setting using the AES1 – AES4 buttons.
In Dual or Quad AES modes, the unit will warn you of missing wires with a
display like 1-34 (AES2 not connected for Quad AES). Swapped wires causes a
display like 1243 (AES3 & 4 swapped). The checking relies on correct
messaging and may not work with non-dCS equipment.
Filt -
(Filter). Selects one of several anti-image
3
filter responses. The filters should
be evaluated by ear. Filt1 gives the sharpest cut off, just below half the
sampling frequency. This is the normal setting. Filt2, Filt3, Filt4 give
progressively more relaxed responses, slightly degrading the Nyquist image
performance but sharpening the impulse response. This affects the stereo or
multi-channel image. Different filters may be appropriate for different material.
A typical audio signal contains very little signal energy above 10kHz, so there is
some justification for relaxing the filter attenuation as 20kHz is approached.
DSD mode also has four filters. Metering DSD is difficult because the high level
of ultrasonic noise can cause spurious meter readings. DSD Filt4 is specially
designed for metering the 0 – 20kHz band and may not give the best sonic
performance.
BNC I -
(BNC Inputs). In PCM mode, this sets the format of the BNC In connectors.
SDIF Configures Ch1, Ch2 and Clk In as an SDIF-2
interface.
AES Configures Clk In to accept AES3 encoded data at
TTL levels at up to 96kS/s.
Select these inputs using the BNC button.
If the unit is already locked to SDIF or DSD, the AES option is disabled.
3
Nyquist images, not stereo images. These are reflections of the pass-band spectrum about Fs/2 caused by
any digital-to-analogue conversion process. They must be filtered out by the converter.