It's pure Class G
What is the Arcam AVR750?The AVR750 is Arcam's latest flagship audio video surround sound receiver and in these days of multi-channel immersive audio, it's interesting to see such an unashamedly old-school approach to receiver design.
Arcam have stripped away anything unnecessary to concentrate on the best possible audio performance with both movies and music. To achieve this they are using seven channels of Class G amplification but more on that later. By their own admission the company had some reliability issues with the AVR600, so perhaps this explains their more basic approach to the AVR750 - which was beta-tested for six months before it was even released.
The mantra would appear to be 'keep it simple and do it well' but, with a recommended retail price of £3,999, the Arcam will be facing some serious competition. At the time of writing (April 2015), you can pick up the AVR750 for around £3,200 thanks to trade-in programme but even so it's still an expensive AV receiver. Let's see if Class G is worth the extra cost...
DesignArcam's minimalist approach is evident when you first get the AVR750 out of the box with a spartan front plate that even eschews the traditional input selection and volume dials. You can still select different inputs and change the volume but you use a series of buttons rather than control dials. To be honest dropping them makes perfect sense, after all when's the last time you selected a different input or changed the volume using anything other than the remote control.
So what you do get is a large and informative display that is easy to read from across the room and can be dimmed if necessary. Beneath this display are a row of buttons that can be used to select sound modes, change inputs or adjust the volume. There is a strip along the bottom but this isn't a flap to access more connections, it's just a design feature and an air vent. In fact the AVR750 doesn't have any inputs on the front, aside from a headphone socket and an analogue input, both of which use 3.5mm jacks. The analogue input also doubles as the connector for the included setup microphone.The minimalist design is actually the second thing you'll notice because undoubtedly the first thing will be the weight of the AVR750. This receiver is built like a tank, with a superb level of construction, a black metal finish and a well engineered appearance. The AVR750 measures 433 x 425 x 171mm (WxDxH) including its speaker terminals and feet and weighs in at 16.7kgs.
Arcam have taken a minimalist approach to the AVR750 but it looks attractive and is built like a tank.
ConnectionsThe minimalist aesthetic that has been employed on the front, also applies to the rear where you'll find all the inputs that you'll actually need, rather than dozens of legacy connections that you'll never use. It's a shame more manufacturers don't have the courage of their convictions when it comes to shearing their receivers of unnecessary connections. It would make receivers less daunting and easier to setup. So what do you actually get? Well there are seven HDMI inputs and two HDMI outputs, both of which support ARC (Audio Return Channel), and all of which support 3D and 4K. In terms of other video connections, there are three component video inputs and four composite video inputs, along with a composite video output. There are also six stereo analogue inputs using RCA connectors and a stereo analogue output.In addition, there are four coaxial digital inputs, along with two optical digital inputs. The AVR750 also has 7.1-channel pre-outs using RCA connectors, an RS232 serial connector, a USB port, a LAN connector, IR extenders, two 12V triggers and an aerial for both FM and DAB radios. There are also gold plated speaker terminals for the seven channels of built-in amplification.
AVR750 Remote ControlsThe AVR750 comes with one of Arcam's standard remote controls, which is slim, light and made of black plastic. The remote is comfortable to hold and easy to use, with a backlight that will prove useful in a darkened room. All the buttons that you need to setup and control the AVR750 are included and you can also control other Arcam products.
If you have an iPad then you also have the option of using Arcam's free remote app rather than the provided remote control. The app is well designed, attractive to look at and highly intuitive to use; making it an effective way of setting up and controlling the AVR750. In fact our only complaint would be that it's not currently available for the iPhone or any Android devices.
The menus and setup retain the same simplicity and emphasis on performance as the rest of the receiver.
Setup and TestingSince the emphasis with the AVR750 is on simplicity and sound quality, that philosophy also extends to the menu system, which is functional rather than attractive. Whilst the setup procedure isn't as detailed or as flexible you will find on some other receivers, Arcam include everything you need to get the best sound quality from your new AVR750. In general, the more that you can get right when setting up your receiver and speakers, the less you'll need to compensate later. This isn't always possible but if you can setup up tonally matched speakers in the correct positions and ensure you've selected the right crossovers, you'll be more than halfway there. You'll need to position your subwoofer carefully and there are plenty of RTF apps available that can help you with this.
Then you'll need to measure the distances of all the speakers from the sweet spot for the delays and set the levels using the built-in test tones and an SPL meter. The AVR750 does include an Auto Speaker Setup which uses test tones and a microphone to measure speaker positions, sizes, delays and levels, as well as apply room equalisation filters. The auto speaker setup only takes measurements from the sweet spot and always try and use a tripod for the microphone, never just put it on the back of a chair or a sofa. Arcam recommend that you address as many issues as possible during setup but the auto speaker setup is there for any issues that you can't deal with directly.We predominantly tested the AVR750 in a 7.1-channel speaker setup for movies, although we also tried a 5.1 configuration for some films. Our primary source for films was Blu-ray with Dolby TrueHD and DTS-HD Master Audio lossless soundtracks. We also listened to multi-channel SACDs, as well as two channel music via CD, SACD, FM/DAB radio, Internet radio and streaming content from our home network.
AVR750 Features & SpecsThese days an AV receiver seems to have more features than a Swiss Army knife, so it's refreshing to see a manufacturer eschew loads of the bells and whistles in favour of pure sound quality. It's a brave move because in a crowded market place a receiver needs to find a way to draw attention to itself, especially at the AVR750's price point. However the reality is that most of the features found on your typical AVR never actually get used and what you really want is something that sounds great with movies and music.
To that end, the AVR750 supports all the popular surround formats including Dolby TrueHD, Dolby Digital Plus, Dolby Digital EX, Dolby Digital and Dolby Pro Logic IIx. It also supports DTS-HD Master Audio, DTS-ES 6.1 Discrete, DTS-ES 6.1 Matrix and DTS 5.1. There is also support for ARC, 3D and 4K over HDMI, as well as video processing up to a 4K resolution; and for system control there's Ethernet, along with RS232, 12V triggers and standard IR. If you're looking for music sources there's a built-in FM/DAB tuner, along with Internet radio, network capabilities for uPnP audio servers and a USB port for connecting memory devices and iDevices.
So what don't you get? Well obviously there's no support for the new immersive audio formats - no Dolby Atmos, Auro-3D or DTS:X. However given the current lack of much content that uses these formats and the general resistance to adding height or overhead speakers, that might not be a great loss. The AVR750 includes a wired connection but no built-in WiFi support and although there is a remote app, it's only available for the iPad - so there's no support for the iPhone or any Android devices.
What is Class G?As we've already mentioned, the main philosophy when designing the AVR750 was to deliver the best sounding AV receiver possible. So Arcam have once again turned to Class G amplification to deliver the kind of power, transparency and control necessary. Most conventional amplifiers either use Class A or Class A/B and both of these have pros and cons. In the case of Class A, the main advantage is that it doesn't suffer from crossover distortion, thus sounding transparent and offering realism through low level accuracy. The downside is that Class A is hugely inefficient, drawing power even when there is no signal to amplify. Class A/B is far more efficient but it does suffer from distortion at low levels.
That brings us to Class G, which is essentially a hybrid of the two other types of amplification. Class G is complex to design and expensive to engineer but, when done correctly, it can offer greater transparency with more efficiency and less wasted heat energy. Like a hybrid car engine, Class G implements multiple power supplies rather than just a single supply. If a dynamic signal is received that goes beyond the capability of this first power supply, the secondary supply is gradually brought in up to full rated power output as required. This gives a very efficient design as additional power is only used when required and modern high speed silicon allows Arcam to make this switch faster than would ever be required, even way beyond the audio bandwidth, so there is no lag.
The first power supply in the AVR750's amplification is of lower power and within this region Arcam run in pure Class A, which has no crossover distortion. As the secondary supply is only used when required, extreme levels of power are possible because very little energy is wasted in the amplifier as heat when it is not being used. Without control this power would be ill-used, so multiple output devices within the amplifier keep a tight grip on the loudspeaker at all times, ensuring your listening experience remains focused. This approach allows Arcam to have seven channels of highly effective amplification into the AVR750, delivering a level of performance that would be impossible with only Class A.
Arcam AVR750 Unboxing Video
Arcam AVR750 Movie Sound QualitySo let's get down to the important stuff, how does the AVR750 actually sound with movies? In a word - superb. It might not be cheap but Arcam's careful design and use of Class G amplification has clearly paid dividends. The AVR750 can deliver an exceptional level of transparency that perfectly renders all the detail in the original soundtrack. The receiver also has plenty of muscle under the hood but retains the ability to remain controlled, resulting in a performance that is both powerful and sophisticated.
We used a dedicated home cinema that has been acoustically treated for testing, so we were in a position to setup the AVR750 without the need to compromise and as a result generally found that we preferred to not use the room equalisation. However if you do need to adjust for the effect of your room, at least you have that option. We carefully positioned the subwoofer to ensure the bass was well integrated with our front floor standers and we selected the appropriate crossovers for all the speakers.
We also have the luxury of being detached and a long way from other houses, so there was no problem with us listening to movies and music at reference volumes. All this meant that we were able to take full advantage of the AVR750's capabilities and we were suitably impressed. The first thing that we noticed was that room itself seemed to disappear and although this is helped by the fact that with the lights out you can't really see the speakers, there was a greater sense of immersion.
It was certainly a timely reminder of just how good 7.1 and 5.1 soundtracks can sound and raises the question of whether you really need to start hanging speakers from the ceiling in order to feel immersed in a film's acoustical soundscape. Since it had just arrived we watched the Blu-ray of Interstellar and found ourselves impressed in the first couple of minutes. The soundtrack goes from very quiet to suddenly hurling you into an out of control spaceship and the surrounds and subwoofer just burst into life around you.
The effect was quite jolting, just as Christopher Nolan intended, and reminded us just how important dynamic range and headroom are when listening film soundtracks. Interstellar takes full advantage of this dynamic range, moving a full rocket launch to the utter silence of space. The AVR750 handled dialogue extremely well, keeping it clear and anchored to the centre channel, even if Nolan seemed to want the dialogue to be less intelligible in certain scenes.
We also had The Hobbit: The Battle of the Five Armies to watch and once again the AVR750 delivered a spectacular performance with what is a highly active and very well designed soundtrack. Smaug's attack on Lake Town uses every channel to full effect, sounds panned seamlessly around the room and the bass shock the foundations. However the Arcam never lost focus, maintaining a cohesive sound field with effectively steered effects, well integrated bass, clarity and detail. Overall the AVR750 delivered a barnstorming performance with movie soundtracks.
The AVR750 delivered a detailed and transparent performance with movie soundtracks.
Arcam AVR750 Video Review
Arcam AVR750 Music Sound QualityIf someone buys an AV receiver, they probably want it primarily for listening to multi-channel movie soundtracks but there's no reason why watching movies and listening to music should be mutually exclusive. In general most receivers tend to be superior at handling movie soundtracks and if someone wants to critically listen to music, they're better off buying a dedicated stereo amplifier. However, thanks to the AVR750, you can do both just as well with one receiver meaning that you won't have to compromise.
The Arcam can obviously accept two-channel audio via a number of sources including analogue inputs, optical digital, coaxial digital and HDMI, along with USB and over a network. There's also the built-in FM/DAB tuner, Internet radio and support for MP3, MP4, WMA, WAV, FLAC and AAC file types. This means that there's no shortage of musical sources to listen to and the AVR750 handled them all with consummate skill.
We have been listening to The Waterboys new album Modern Blues recently and Mike Scott recorded the album in Nashville with a number of hugely talented session musicians. The result is an album that is full of wonderful arrangements and inventive playing, all of which was beautifully reproduced by the AVR750. The higher frequencies were carefully picked out, whilst the mid-range remained well defined and detailed. The bass notes were also nicely rendered, underscoring the music and holding it all together.
Another album that we've been listening to a lot recently is Hendra by Ben Watt and again the AVR750 proved to be something of a revelation. The wistful vocals of Watt himself were carefully layered along with Bernard Butler's wonderfully melodic guitar playing, resulting in songs that were both bucolic and melancholy. There were times when the detail and clarity brought out the sound of Butler's fingers running along his strings on one track or the metallic sheen of David Gilmour's slide guitar on another. All these factors combined to deliver a very effective and transparent performance that made listening to music hugely enjoyable.
The Class G amplification provided incredible transparency and responsiveness with music.
- Superb sound quality
- Simple and attractive design
- Excellent build quality
- No support for new audio formats
- Remote app only supports iPad
Arcam AVR750 7.1 AV Receiver Review
Should I buy one?That very much depends on what you're looking for but if superb sound quality is your goal and you have sufficient budget, then the Arcam AVR750 should definitely be on your short list. The receiver's performance with 7.1 or 5.1 movie soundtracks was simply stunning and the use of Class G amplification clearly paid dividends. If that wasn't enough, the AVR750 was among the most impressive receivers we have ever heard with two-channel audio, making it the best of both worlds.
Don't expect flashy looks, slick interfaces and tons of features because you won't get them. The AVR750 is all about minimalism, simplicity and performance; although the design remains attractive in an understated way and the build quality is excellent. There are plenty of connections at the rear but the emphasis is obviously on HDMI with support for ARC, 3D and 4K; along with video processing up to 4K. The provided remote is effective but the remote app currently only supports the iPad. However, as long as you don't want decoding for all the new immersive audio formats, the Arcam AVR750 is an impressive if somewhat expensive high-end AV receiver.
What are my alternatives?In terms of seven-channel AV receivers, the obvious alternative to the AVR750 is Anthem's superb MRX 710. Like Arcam's latest flagship, the MRX 710 is all about performance rather than looks and features but it does boast the best room equalisation software that we've tested on a receiver. Anthem Room Correction (ARC) is far more sophisticated and flexible than anything on the Arcam, giving you greater freedom to fine tune the effect of your room. The majority of the features are similar between the two and although Anthem doesn't use Class G amplification it still sounds wonderful with both movies and music. It's also quite a bit cheaper and you can pick up the MRX 710 for around £2,000 at the moment, making it still a hard act to follow.
However if you're looking for an AV receiver that does the lot, then look no further than Denon's awesome AVR-X7200. Whilst this also doesn't use Class G amplification, it's mono-block design delivers a great performance with both movies and music. It comes with nine channels of amplification and supports just about every audio codec you can think of including Dolby Atmos, Auro-3D and DTS:X. It's also very attractive, extremely well built and has a very slick user interface, making setup easy and flexible. There are connections and features galore, effective remote controls including apps for iOS and Android and Denon will even be adding HDCP 2.2 very soon. If all that wasn't enough, the Denon AVR-X7200 can now be picked up for the very tempting price of £1,849.
Value For Money8
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