The Rotel RSX 1562 takes a bold step in a different direction by the use of a recently developed (and still early stage) audio amplifier technology called "Class D." While many fuller technical descriptions of Class D amps abound on the web (including lively debate on its pros and cons), here's a good short way to describe what's going on with this next-generation technology -- which almost certainly will be the way of the future in most audio amplifier designs.
When D Is A Good Grade
Your receiver's amplifier's job to provide ample electrical energy to react to music in real time to musical information, and send the energy on to the speakers to make them vibrate and move air. This is what your ears hear as music.
The vast majority of receivers on the market use a time tested amplifier technology called A/B. Briefly put, these amplifiers have a small but constantly available store of current in reserve to draw from and send to the speakers as the music goes by. There are class A amplifiers too, which are usually very expensive and energy inefficient, and often work with old-school vacuum tubes. They are considered the cream of the crop, if you can afford one. A/B amplifiers are much more prevalent and practical, and yield sonic results that run the gamut from sublime to unlistenable. You can read a layman's explanation of these amplifier technologies that I've written here.
Class D amplification uses a different approach. Among other things, it is able to draw tremendous reserves of power virtually in real time, just as it's needed. Because there's no need to store current in reserve, a Class D amplifier uses less energy, produces much less heat (the enemy of all things electronic) and can be made much smaller. A high-end A/B audio amplifier can weigh in excess of 100 lbs. A Class D amplifier can give you the same power in the palm of your hand. Before we discuss the actual listening, let's look at the rest of the Rotel RSX 1562.
Setup And Connectivity
As these things go, the Rotel is a pretty crude customer in comparison to its more tricked out competitors. There's enough connectivity for a good sized home theater system -- 6 HDMI inputs, including one with the audio return channel (ARC), which eliminates the need for a second digital audio cable that some components require. There are 4 optical digital audio connections and 3 coaxial -- this is clearly a receiver that has put audio playback first and foremost as its calling card.
The RSX 1562 can power 7.1 channels of surround sound, giving you outputs for a rear center channel and "height" channels for your surround speakers. It can also power up to 4 "zones" (rooms), for sound around your house. It has a built in AM-FM tuner, and a front panel input USB port for iPods or a flash drive. The receiver also comes equipped with a Bluetooth dongle that slips into this port, so you can wirelessly stream music from your phone or other Bluetooth device.
The setup menu here, to put it bluntly, is pretty crude. You won't see snazzy colors or icons, it's basically a text-driven interface with no frills that gets the job done, however inelegantly. You can save custom settings to each input, which is nice. There is no room correction provided. Instead, Rotel has included a parametric equalizer, which is a fabulous feature -- if you're an installer with the proper audio spectrum analyzer, or an extremely advanced enthusiast who knows how to properly use this powerful tool. Most ordinary consumers will not use this feature, at least not very effectively.
As regards the remote control, suffice it to say that it's not impressive. While it's a safe bet that most people who would consider a receiver of this caliber will likely use a 3rd party universal remote control, Rotel had to include one with the receiver of course, and while not the worst I've seen in terms of complexity, its button layout is questionable. Whether lefty or righty, unless you hold the remote just so, you'll almost always be touching buttons that you don't want to, even for something simple like adjusting the volume.
The featured attraction here is the sound, and I want to come out and say that I think the Class D amplification used here is going to impress a lot of people. This is clearly a different sound than we're used to, particularly at lower volumes. The sound is remarkably fast and effortless, with an almost 3D presentation of individual instruments and a sound stage that stays rock solid. There's incredible snap to percussives like snare hits; you can hear the guitarist move fingers up and down the strings, you can hear the vocalist taking a breath. This is detail writ large, and you hear it even when you're playing it low volumes. Which is a good thing because there's no Dolby Volume or other dynamic compression offered on the Rotel.
My reference speakers are huge towers with 12-inch passive woofers. That means, in essence, that I've got two subwoofers going, both of which depend on power from the receiver (or amp) to make them sing. They need a lot of energy just to make bass, and on most amps, you've got to turn up to at least a moderate volume level to hear a coherent presentation, where the bassist isn't getting the short end (as bassists often do).
The audio presentation from this Rotel is kind of astonishing, particularly at low levels. It had absolutely no problem driving these huge speakers and getting controlled, articulated bass that was really in the mix without having to turn the volume up. I don't mean to say that the Rotel can't play loudly -- at 100 watts per channel it has plenty of muscle. But the amount of detail at normal, family-friendly listening levels was very different than what I've come to expect from A/V receivers, and frankly, many separate dedicated power amplifiers.
This is truly a different kind of sound. If you imagined sound as a photograph, the Class D 'picture' would yield tremendous contrast, brightness and sharpness -- more than you were used to seeing. If you looked under a magnifying glass, the color (tonal) rendition and gradations might not be what you're used to, and perhaps not up to the standards of the highest quality separate amps and the beloved analog-y sound that audiophiles obsess over. Class D is still a nascent technology and it will get even better over time. But even now, this is seriously impressive and a real differentiator.
This is audio that really does grab your attention and really does stand out from the crowd. If you're the kind of listener that sits up close in rapt attention to automobile-priced speakers, delights in endless cable swapping and and scours the web for vintage tubes in hopes for a smidge richer overtone here, a micron more harmonic depth there, you may not like the sound of this receiver. It is unapologetic in its presentation, more of a photograph than a painting, and one of the things it does right -- better than any tube amp I've ever heard -- is handle dynamics with ease. Which not only makes it a receiver that can rock out with the best of them, but makes surround sound movies really jump out at you.
At $2599, the Rotel RSX 1562 is a serious A/V receiver investment, and you have a right to expect a lot. It doesn't have a lot of bells and whistles; in fact there's a paucity of them. The setup menu (not that you'll use it so often) looks like Atari circa 1986. The best things you can say about the remote control are that it's light and relatively uncluttered. There's no automatic room correction, no video processing, no XM or HD Radio.
This is a receiver that has been designed for the music lover who values performance above all, and its calling card is sound that will get you excited about your receiver. The video pass-through is fine, and the movie surround is exceptional. But it's the musical representation that grabbed me and I think will grab you. Not everyone likes the distinct sound of the Class D amps included in this receiver. But then I remember people who thought DVD didn't look as good as Laserdisc, and for pretty much the same reasons -- they thought it was too "digital."
The Class D amps in the Rotel RSX 1562 aren't digital per se. But they stand out dramatically from the competition and will perk up your ears the same way that CDs did when they came out, when you first heard the detail, separation and noiselessness that they were capable of, compared to what you were used to.
In all fairness, this is a pretty premium price point for an A/V receiver, and while performance is usually where you separate the men from the boys, there are numerous competitors out there that dollar for dollar, will give you more things to play with than the Rotel, if that's your idea of a good time. They will have slicker user interfaces, more surround simulations that you may or may not use, and user adjustments for the video that may get you a better picture (if you're skilled and experienced) or mess up what you have (if you're not).
That being said, I strongly recommend an audition of this receiver, and if possible, ask your dealer to do an A-B comparison with a similarly priced (and more conventional) receiver. The differences you hear won't be subtle, and it's my guess that most people will love it. I can't wait to hear how this technology continues to evolve.