Some AVR makers think advanced features and functions are what most home theater enthusiasts want, but Cambridge Audio’s Azur 650R 7.1-channel A/V receiver is built for audio purists believe that less is more, simpler is better, and that the shortest path to great sound involves amplifier circuits that inject as little technical gobbledygook as possible in the signal path. This does not mean, however, that the Cambridge is not modern or up to date, because it is both, but rather that its priorities are simply different from those of most mass-market receivers. Instead of focusing on technical gongs and whistles, the Cambridge instead concentrates on providing a rugged, purist-grade amplifier section that’s backed up by a simple but effective bank of audio and video switching facilities and a powerful but no-nonsense set of surround sound decoders.
In keeping with the purist aesthetic, the 650R takes a “first, do no harm” approach in handling both video and audio signals. Accordingly, the receiver provides composite video, S-Video, component video, and HDMI (version 1.3c) video inputs and supports transcoding between those formats, but otherwise makes no attempt to provide more elaborate video scaling or processing functions. Similarly, the Cambridge provides a useful mix of analog (stereo and 7.1-channel) and digital (coaxial, optical, and HDMI) audio inputs, but takes special pains to give users the option of listening to audio signals with little or no signal processing or tone shaping applied. The latest Dolby TrueHD and DTS-HD Master Audio surround sound decoding modes are supported, but otherwise DSP modes are held to a minimum (Cambridge supports five basic alternative modes called Movie, Music, Room, Theatre and Hall). Finally the 650R incorporates an automated speaker setup system called CAMCAS (Cambridge Audio Mic Controlled Auto Setup) that provides basic channel level and speaker distance settings, but that pointedly does not offer room/speaker EQ functions. The sense one gets in setting up and then using the Cambridge on a day-to-day basis is that it is meant to be clean, simple, and straightforward in every way—giving you all the essentials you need, and nothing you don’t need or aren’t likely to use.
Frankly, I can see how two very different reactions to the Cambridge receiver might be possible. Enthusiasts who appreciate and expect the densely layered features commonly found in competing higher-end AVRs might find the Azur 650R seems, well, a little spartan. But high-end audiophiles, who are often skeptical of whizz-bang circuit add-ons that promise great things but that ultimately do more harm than good, will feel right at home with the approach Cambridge has taken. Let’s take a closer look at the 650R to see how it performs under real world conditions.
Consider this AVR if: You are a purist at heart and know and love the sound of good, clean, powerful amplification when you hear it; this is really the 650R’s greatest strength. Also consider the Cambridge if you would like an AVR that offers specialized controls (for example, the ability to set individual subwoofer crossover frequencies for each channel in fine, 10Hz increments) that audiophiles will actually want to use.
Look further if: You want a receiver that offers large numbers of HDMI inputs (the 650R offers only three), that provides automated room/speaker EQ functions (the 650R has none), or that incorporates a high-powered onboard video processor (the 650R supports format-to-format transcoding, but stops there). The 650R is not cheap, which may lead some to ask whether it is overpriced, but what you are paying for is amplifier circuitry that sounds much better than the norm for this price class.
Ratings (relative to comparably priced AVRs):
User interface: 8
Sound quality, music: 9
Sound quality, movies: 9
• A key centerpiece of the 650R involves its 7 x 100-Watt amplifier section, which is rated with all seven channels driven. Cambridge has this to say about the amplifier section: “the seven 100W audiophile grade fully discrete amplifiers are kept as separate as possible from the processing and input stages and feature a large power supply with a low flux toroidal transformer.”
• Provides a massive X-TRACT forced-air cooling tunnel that occupies a large center within the 650R’s chassis, and that runs from the front of the unit to a large vent in the rear panel. This is precisely the sort of construction detail you might expect to see on a big multichannel power amplifier, but that is relatively rare in AVRs.
• Unused amplifier channels can be used to bi-amplify main loudspeakers.
• CAMCAS (Cambridge Audio Mic Controlled Auto Setup) system provides automated speaker level and distance setting via included calibration mic.
• Allows users to set individual subwoofer crossover frequencies for each channel in 10Hz increments from 40H to 120Hz.
• For listening to stereo sources, the 650R provides both a pure “Stereo” playback mode and a useful “Stereo + SW” mode that digitally applies whatever subwoofer crossover setting have been chosen and that digitally derives a subwoofer output signal from standard two-channel signals (analog or digital).
• Provides extensive Tone/Sub/LEF configuration setting with a broad range of subtle trim options.
• Audio Split mode allows viewing one input while listening to another.
• Tuners: The receiver provides standard AM/FM reception.
• Provides A-BUS/Cambridge Incognito support for two addition zones, if desired.
• Three HDMI inputs (version 1.3c).
• Supports Dolby TrueHD and DTS-HD Master Audio surround sound processing modes.
• Supports high resolution PCM bitstreams.
• Uses Cirrus Logic CS43122 24-bit/192 kHz DAC for front left and right channels.
• Uses Cirrus Logic CS52526 24-bit/192 kHz CODEC for surround channels + 24-bit A/D conversion.
• Uses Cirrus Logic CS497004 dual 32-bit DSP.