Owner's Manual

8
Cambridge
Audio
Operating instructions cont.
Setup
.----------Menu
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USB
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Front
IR
-
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Play
Class
Naming
Version Volume Balance
,
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On
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5m
10m
15m
Th
e
851C menu structure has a variety
of
setup parameters
that
can
be adjusted
to
suit
both specific installation requirements and personal
preferences. The setup parameters are accessed and modified through
a menu driven interface
that
uses
the
851C
display along with i
ts
front
panel or handset
Menu, Select,
Skip(~
~)and
Stop
(
•)
buttons.
To
enter
the
851C
setup menu, first press the front panel or handset
Menu
button. The first setup parameter (Auto Off),
will be shown
on
the
display.
To
select further parameters for adjustment press
th
e one of
the
front panel or handset Skip
(
H~
~)
buttons.
With
the
required parameter selected, press the front panel or hands
et
Select
button. Pressing one
of
the
Skip
(~
~)
buttons
will
now
scroll
through
the
options available for
that
parameter. When
the
required
option is displayed, press
the
front panel or handset
Select button.
The setup option is now stored.
To
exit from
the
setup menu interface
press the front panel or handset
Menu
button
to
step back through the
interface.
Note:
Th
e
85
1C will
automatically return
to
normal play mode
if
it
is
left
inactive in setup menu mode for more than a minute.
Each
setup parameter and its options is described following paragraphs.
Auto
Off
- When Auto
Off is engaged
the
851C will switch
to
standby
after a preset time
if
no audio is playing. The Auto Off options are
Off,
5
minutes,
10
minutes and
15
minutes.
Auto
Play -
With Auto
Play
engaged a
CD
will begin
to
play as soon as
the
disc drawer is closed.
Th
e Auto Play options are Off
and
On
.
USB
Class -
USB
Class
options enable
851C compatibility with both
USB
Audio
1.0
and
USB
Audio
2.0
int
erface formats. The default s
ett
ing is
USB
Audio
1.0
which will work driverlessly with most operating systems
for 16-24
bit
content
at
32-96kHz. Note
USB
Audio
2.0
requires a driver
to be loaded
for
Windows. Without this selecting
USB
Audio
2.0
will
normally
give no
output.
See
section on
USB
Audio for advanced users.
Input
Naming-
Input
Naming enables
the
display name
of
the
Digita
l1
,
Digital 2 and AES/EBU inputs
to
be changed. Use
the
S
kip(~
~)and
Select
button to select
the
input name
to
be changed.
Once
selected
a flashing cursor will appear beneath
the
first character
to th
e existing
name. The
Play/Pause
and
Stop
(
•)
buttons can
the
n be used
to
scroll
through
the
available characters. When each desired character is
displayed, use
the
Skip(
~
~H)
buttons
to
move on
to
the next cha
ra
cte
r.
Press
the
Select
button
to
store
the
new name.
S/W
Version -
Se
lecting
S/W
Version
displays
the
player's
int
ernal
operating software version number and some additional build
information. This information is primarily provided for service personnel.
Front
IR -
Selecting Front
IR
enables
the
851C
front panel infrared
receiver
to
be switched on or
off
(if
you are using an external
IR
system
and
the
IR
emi
tt
er
Input
or
Control
Bus.
In
the majority
of
installations
the infrared receiver should be le
ft
switched on.
Digital
Vol -
Digital
Volume
enables
the
851C
to
operate as a digital
preamplifier and be connected directly
to
a power amplifier. With Digital
Volume
engaged,
the
remote handset volume buttons (symbols)
will
control
the
851C
analogue
output
leve
l.
Digital
Volume is disengaged
(Off)
by
default
and should remain
off
in most
851C
installations.
It
should only be engaged
(On)
if
the
851C
is
installed
in an appropriately
configured audio system without a further downstream volume contro
l.
Ch.
Balance - Only
enabled when
Di
gital Volume
is used. A balanced
control is implemented.
12
Filters
The
851C
DSP
has three different Filter functions: Linear Phase,
Minimum Phase and
Steep.
All
th
ree filters are highly sophisticated
audiophile topologies, optimised specifically for audio playback. In
our
opinion,
th
ese filters offer excellent sound quality but differ subtly in
optimisation, hence we've made
all three available to you.
Note:
For
clarity, all diagrams show the theoretical response
of
the
DSP
itself, excluding any analogue filtering
at
the
DAC
output or
the
anti-
aliasing filter applied during recording
and/or
mastering
of
the digital
source.
Linear Phase Filter
Frequency response
T
I
-T
I
i
-20
i
-40
L
___
;
j-
~
·
60
f
I
"'
-80
~
I
c
100
r-
"'
"'
::;;
-
120
-
14
0
·i
--·-.
-
--
-·
-
160
~
-
---
-
.
T
.L
-1
80
I
-
200
;
0
.1
0.2
0
.3
0.4
0
.5
0.6
0.7 0.8 0.9
Frequency response
The Linear
Phase
filter is a highly regarded audio filter offering low ripple
in both the pass and stop
bands, and
wh
at
is known as consta
nt
group
delay.
Const
ant
group delay means
that
audio signa
ls
of
all frequencies
are alw
ays
delayed by
the
same amo
unt
when passing through
the
filter.
All audio is therefore
fully
time
-coherent at
the
output.
The trade-
off
with
thi
s type
of
filter is
that
due
to
internal feed-forward
in
the
DSP,
its impulse response
will exhibit some pre-ringing.
In
other
words, when excited with a theoretical impulse, the output has both
a
small
amount
of
pre- and post-spike amplitude ringing
(a
lbe
it
well
damped).
"'
-g
-
""
a.
E
<(
20
40
60
Fr
equency respon
se
80
1
00
120
140
1
60
180
Frequency response