High Quality Sound Reproduction: The Cambridge Audio Azur 651A
integrated amplifier has been designed and engineered to deliver the purest,
most realistic sound reproduction possible; free from interference or
Full Metal Chassis: The 651A integrated amplifier features an
acoustically damped, low resonance full-metal chassis with a thick, brushed
75W x 2Ch Integrated Amp: The Cambridge Audio Azur 651A delivers an impressive 75 watts per channel into 8 ohms,
at 20-20kHz, with 0.03% THD at 80% rated power.
Fully Discreet Amplifier Circuitry: The 651A integrated amplifier has
separate transformers for left and right channels, twin rectifiers, and separate
PSUs for dual mono operation of the left and right power.
ALPS " Black Box" Volume Encoder: The 651A integrated amplifier uses a
high end ALPS "Black Box: volume encoder that all of the signal goes through this
at all times, so this is a very key component. Benefits include perfect channel
balance at all volume levels and improved and stereo separation.
Toroidal Transformer: Unlike a lot manufactures who use cheap laminate
type transformers, the 651A use an audiophile grade toroidal transformer
offering minimal electro magnetic interference and delivering superior audio
Heat Sink: The 651A integrated amplifier features substantial
extruded heat sinks, allowing the amp to deliver incredible power and control.
New low inductance resistors and polypropylene
signal capacitors are used for superior audio performance.
Buffered Input Circuitry: The 651A features buffered input circuitry for
superior audio performance, including lower crosstalk and improved stereo
imaging. It also uses new low dissipation polypropylene signal capacitors and
custom made electrolytic capacitors in critical positions.
Redesigned Output Stage: The 651A integrated amplifier uses completely redesigned output stages with new Sanken output transistors,
improving bass response and dynamics even further.
5-Way Protection System: Cambridge Audio has developed a
proprietary protection system to ensure reliability and long life of its
amplifiers. This proprietary protection system is known as "CAP5 protection
circuitry". This protection system comprises five main protection methods:
- DC Detection: CAP5 offers loudspeaker protection if the output of
the amplifier goes to a high constant voltage (DC).
- Over Temperature Detection: AP5 includes
temperature detection which constantly monitors the heat generated by the
output transistors. If the monitored temperature reaches a high level
(suitably within the limits of the output devices) the amplifier will
automatically switch into a fault mode.
- Over Voltage Detection: CAP5 offers V/I protection by constantly
monitoring the output transistors to keep them working inside their Safe
Operating Area (SOA). The SOA is a set of limits given by the output
transistor manufacturer to ensure reliability. V/I also protects the
amplifier against short-circuits on the speaker terminals during use.
- Short-Circuit Detection: During power up from Standby, CAP5
performs a check on the loudspeaker terminals to see if a short across the
terminals has been accidentally introduced. If the resistance measured
across the loudspeaker terminals is too low, the unit will remain in Standby
mode until the fault has been removed and power up is re-attempted.
- Intelligent Clipping Detection: CAP5 has the ability to detect
when the amplifier starts to clip or overdrive at its output, which can
damage loudspeakers and degrade the sound. Clipping distortion is caused at
high volume levels when the output signal briefly goes outside the maximum
voltage that the amplifier can provide, causing the tops of the signal to
flatten off. When CAP5 detects clipping, the volume will be automatically
nudged down until CAP5 detects an undistorted output.
Standby Circuit: This innovative new circuitry design allows 651A
integrated amplifier to consume less than 1 watt of power when in Standby, but
itself remains totally isolated and non-detrimental to the sound quality when
the amplifier is in operation.
Main Power Switch: The 651A integrated amplifier's main
power on/off switch is located on the rear-panel.
Standby/On: Once the amp's rear-panel main power switch has been
turned On, you can switch the 651A On/Off using the front-panel Standby/On
Volume: Use the front-panel rotary volume control to increase or decrease the
level of the sound from the outputs of the amplifier. The volume control affects the level of the loudspeaker output, the preamp output,
and the headphone output. It does not affect the Rec Out connections.
A/B Operation: The Cambridge Audio 651A integrated amplifier lets you
play A speakers only, B speakers only, or A and B speakers together.
Direct: This control gives the audio signal a more direct path to the
power amplifier stage of your amplifier, bypassing the bass and treble control
circuits for the purest possible sound quality.
Bass and Treble: The 651A integrated amplifier has independent Bass
(20Hz) and Treble (20kHz) controls which can be adjusted from +/-7.5dB. The
Bass and Treble controls only effect the speaker and preamp outputs; they do not
effect the record outputs.
Balance: This control allows you to adjust the relative output levels
of the left and right speaker channels. The Balance control only effects the
speaker and preamp outputs; it does not effect the record outputs.
IR Remote Control: The 651A is supplied with an Azur
Navigator IR remote control that operates both this amplifier and Cambridge
Audio Azur-series CD players. The Azur 651AC Navigator remote control can also
control the basic functions of Apple devices, such as Apple TV and Apple's iPod/iPhone/iPad
when docked in a Cambridge Audio or Apple dock (sold separately).
Note: The remote operates off of three "AAA" batteries
Analog Audio Inputs: The Cambridge Audio 651A integrated amplifier is
fitted with five pair of gold-plated analog audio inputs (RCA) to connect your external audio
sources; such as your Blu-ray/DVD player, AM/FM tuner, CD/SACD player, or
Note: The 651A integrated amp is not equipped with digital
inputs/outputs or video inputs/outputs. There is also no Phono input.
Analog Audio Outputs: The 651A integrated amplifier features two
pair of gold-plated analog audio outputs (RCA) that can be connected to a CD
recorder, MiniDisc recorder, or tape recorder.
Front-Panel Aux Input: The Cambridge Audio 651A integrated amplifier
features a front-panel Auxiliary (3.5mm) input to connect your portable MP3
player or other portable audio device.
USB Port: The 651A integrated amplifier is fitted with a rear-panel USB (type-B)
port allowing USB audio streaming from your Windows PC (XP, Vista, 7) or Mac computer
(Mac OSX 10.5 or higher). The USB port
supports 16-bit/32kHz, 44.1kHz, or 48kHz audio.
A-B Speaker Terminals: The Cambridge Audio 651A integrated amplifier
is equipped with two sets of gold-plated, binding-post speaker terminals
(labeled A and B). The use of A and B speaker terminals allow you to hook up
speakers in another room.
Note: When using two pairs of speaker, use only speakers with a
minimum nominal impedance of 8 ohms.
Subwoofer Output: The 651A integrated amplifier is equipped with a
mono subwoofer output to connect a powered subwoofer for added bass response.
Preamp Output: The Cambridge Audio 651A is equipped with two RCA
preamp outputs to connect the integrated amp to an external power amplifier.
Headphone Output: The 651A integrated amplifier offers a front-panel
1/4" headphone output to connect a set of headphones for private listening. When
headphones are connected, the output to both A/B loudspeakers is muted. Use
headphones with an impedance of between 32 and 600 ohms.
IR Emitter: The 651A features a IR Emitter input (3.5mm) which allows
modulated IR commands from multi-room systems or IR repeater system to be
received by the amplifier.
Control Bus: The 651A features a Control Bus Input and Output (RCA),
which allows un-modulated commands from multi-room systems or other components
to be received by the amp and loop out to another unit.
AC Power Cord: The Cambridge Audio 651A operates off of standard
household AC current using the supplied detachable 6' AC power cord.
Azur Series CD Player: The Cambridge Audio Azur 651C Compact Disc
Player (779651CB, sold separately) is the perfect companion to the 651A
iPod Dock: A Cambridge Audio iPod dock makes a great add-on
to the 351 A integrated amplifier (779ID50B,
779ID100B; sold separately).
DacMagic: Get even better sound from your computer's stored
music and Internet radio, as well as add optical/coaxial digital inputs to the
351 A integrated amplifier, with a Cambridge Audio DacMagic external
digital-to-analog converter (779DACMPLB;