Cambridge Audio 551R User Manual

Operating instructions

To activate the 551R, switch the Power button on the rear panel to On then

press the Standby/On button on the front panel.

Selecting the source

1. Select the desired source by pushing the corresponding source button on

the front panel or remote control.

2. If necessary, press the Audio Input Type button to select the input mode of

the source equipment, either analogue, digital or HDMI (depending on the

connection made on the rear panel). You may have already assigned this

in the ‘Audio In/Out Setup Menu’ in the OSD.

The digital, analogue or HDMI icons on the display show which is the

currently selected input type.
Note: The 551R stores the input type for each source so that it is

automatically recalled when that source is selected again.

Selecting the desired listening mode

Select an appropriate mode for the source material/type you are listening to

by pressing the Stereo or Surround Modes button and cycling through sub-

modes where available.

In all cases the first time a mode button is pressed the 551R will report the

current decoding mode on the front panel display. Pressing the button again

will then cycle to the next available mode (if there is one). If no button is

pressed for 4 or 5 seconds the 551R returns to normal operation without

changing mode.
Stereo Modes - Selects 2 channel Stereo operation for stereo material,

pressing again selects Stereo + Sub mode.
This is a digitally processed mode that allows bass and treble controls, and

sub generation if required. The input can be either analogue (in which case

it will be turned into digital by 24 bit A/D conversion) or natively digital.
Surround Modes - Selects a range of digital surround modes for the

appropriately digitally encoded material
Note: Some Surround Sound types (such as the Dolby and DTS HD) are

available only from Blu-ray disc over HDMI.
Pressing the Surround Modes button will cause the 551R to lock onto the

incoming bitstream and select the first available mode for the current

bitstream type.
In some circumstances (see tables) pressing the button again will switch to

an alternative decoding option.

A DTS technology which is able to recreate 6 channel (Left Front, Right Front,

Centre, Left Surround, Right Surround, Surround Back ) surround sound from

suitable analogue matrix encoded stereo source material. DTS Neo:6

material can be played back by normal Stereo equipment (as Stereo) or

decoded into 7.1 by sending the Surround Back decode to the both the

Surround Back Left and Right speakers (forming two mono Back Surrounds).
Note: Neo:6 does not include a Low Frequency Effects channel for the

Subwoofer, but the 551R can create a Subwoofer output via Bass

management. Refer to the ‘Tone/Sub/LFE configuration’ section in the

‘Operating instructions’ part of this manual.

A DTS technology that provides 5.1 channels of 96kHz / 24bit audio (along

with video if required) on DVD-Video and DVD-Audio (video zone) discs (when

suitably encoded in DTS 96/24). DVD players which allow 'DTS digital out'

pass the DTS 96/24 bitstream over S/P DIF or HDMI for decoding in the

551R.

DSP modes

These modes allow a surround-sound experience from source material that

has no encoding at all. The surround sound effect is achieved by Digital

Signal Processing of the Analogue or Digital stereo source used. Five modes

are possible: Movie, Music, Room, Theatre and Hall.

Stereo/Stereo + Sub

Only the Front Left and Front Right speakers (and subwoofer if selected) have

output in this mode. If an analogue source is selected it will be converted to

digital via 24 bit A/D converters to allow digital domain sub creation and

bass/treble controls.
If a digital source is selected the 551R will be processing either LPCM stereo

(from the digital outputs of a CD player for instance) or a Stereo downmix of

DD or DTS material (from the digital output of a DVD player for instance).

Other modes
Analogue Stereo Direct

Selects the analogue inputs for the current source directly with no A/D

conversion, DSP processing, Bass/Treble or subwoofer channel active.

Provides the very best fidelity for analogue Hi-Fi source equipment. In this

mode the 551R is acting just like a normal Hi-Fi integrated amplifier.

Multi Channel PCM

Some playback devices (in particular Blu-ray players) are able to decode

some of the above formats themselves internally and then output the

decoded audio as Multi Channel PCM to the 551R. In addition Blu-ray disks

can support native unencoded Multi Channel PCM soundtracks (of up to 8

channels) on the disc itself. In either case if your player can output these over

HDMI the 551R is able to receive them in Multi-Channel PCM mode.

Surround sound modes cont.