By Jim Bray
If you're looking to give your stereo system a major power and quality upgrade, Rotel has a new pair of pieces that could be right up your alley.
The RB-1590 and RC-1590 is a stereo amplifier and preamplifier combo that not only sounds fantastic, it offers outstanding power and is robust and flexible enough that it can even be a good fit in professional applications.
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I know Rotel equipment well. I've been a fan of their combination of high quality and relatively affordable price since my first review of a Rotel power amplifier back in the late 1980's, and from about Y2K have been using their equipment in my home theatres nearly exclusively. Among the Rotels I've purchased over the years were their 500 watt per channel Class D amps (the RB-1091/1092 combo of stereo and mono amps I use as reference units), and I've been fortunate enough to get "home theatre seat time" with a variety of their products. I watched as the company moved at least part of its focus from more traditional, Class AB power amps to the sometimes-called (erroneously) "digital" Class D amps that bring big power to small, light and efficient packages. Rotel was one of the major proponents of Class D amplification in the "affordable high end" class and the Class D amps of theirs that I've tried - including the still available RMB-1575 - are really sweet.
So it was that when I received notice of the new RB-1590 which, since it's a Class AB amp seemed to be a retrenching from the Class D push, I wondered if the company were abandoning that type of amp. When I inquired, however, I was assured they weren't: "We have not moved away from them, but we have increased the number of Class AB amps we make," their representative said, adding that "Class D still makes the best sense for applications where thermal issues are a concern such as rack mounting and small enclosed areas with not much ventilation. Class D amplifiers are also more efficient and have reduced operating costs."
Meanwhile, the RB-1590 is a very good thing in its own right. I fell under this amp's spell so quickly it was reminscent of a teenage girl swooning over a favourite boy band or, in my age group, the Beatles. I would love dearly to pair (trio?) three of them to create a dynamite 6.1 system like I did with the Class D amp stack (though I only did five channels via two stereo and a monoblock). Alas, the Class AB technology means big size and weight; heck, the single RB-1590 takes up about the same space as my stack of three Class D amps, and I'd have no place to put them easily without causing a divorce. Ah, but what a home theatre that would make!
Before the signal gets to the amp, however, it needs a preamp and Rotel's companion piece, the RC-1590 is a fine one as well. It is also more flexible in today's digital age than the last Rotel stereo preamp I reviewed a few years ago. That's because that older preamp eschewed things digital, which meant you couldn't hook in a CD, DVD or Blu-ray player except via stereo analogue inputs, which limited its flexibility (though it was a fine piece of equipment other than that). That was then and this is now. The RC-1590 can take just about anything, including Bluetooth input, and that means a lot in today's marketplace.
Inside the preamp are separate custom-built toroidal transformers for the analogue and digital circuits, with custom-made slit-foil capacitors (which feature quick "charge/discharge times and low signal loss, to ensure tight bass performance," according to Rotel). I can't really explain what they mean by all that technish, but it's the sound quality that matters anyway - not how they get there - and, as with the new amp, Rotel has done a nice job with this particular component. It's a well and solidly built unit that runs quietly and played everything I threw at it with wonderful fidelity.
Rotel says it designed and tested every aspect of the RC-1590 in extensive listening sessions and that the analogue and digital circuits were designed separately but evaluated together before the design was finalized, all of which must have been fun for the Rotelians involved. As it should, it comes with a high performance phono stage for those who either still have their turntables (I regret dumping my old Sansui direct drive unit a couple of years back) or who have discovered the warm fuzziness of analogue playback more recently. The digital inputs are isolated fully, and feature a precision AKM, 34-bit/768kHz digital to analog converter (DAC) that will handle pretty much everything up to SHM SACD (this, of course, also depends on what signals your source device can send it).
As for connecting the RC-1590, it's full of choices including a pair of balanced XLR inputs and two sets of XLR outputs (for bi-amping) along with the phono input, you get stereo RCA jacks for CD and tuner and also for a pair of buffered subwoofer outputs. Digital inputs include three coax and three optical, plus a front USB for iOS devices and a rear PC-USB port that supports up to 24 bit/192kHz and DSD signals. There's even an aptX Bluetooth receiver. Heck, the thing even has coax and optical digital outputs.
I connected the preamp to the amp via both the RCA and balanced XLR cables - separately, as Rotel advised in its documentation - and was quite happy with it either way. I think the XLR approach is better (well, louder) - and the connections are more solid - but it wasn't enough of a difference for me to advise you to run out and buy XLR cables if you won't be using the system to play at weddings and football games. As a friend in the industry told me, XLR is really designed for professional audio installations and gives improved signal output up to 24 volts, whereas typical RCA runs about 2.5-4 volts. Suffice it to say, the system had no difficulty making my ears bleed with either connection method.
The preamp also features RS-232 and IP control options for integration into automated systems, and you can update its software via the Internet (a pretty easy process as long as you have a wired connection). There are two 12 volt trigger outputs, a dimmable display, an automatic "power off" function (conﬁgurable) and a 3.5mm headphone jack.
The remote control is a newer design for Rotel and despite its lack of backlighting it works well and is laid out logically. You can use the front panel's LCD to tweak various parameters, if you wish. It's a bit clunky and I wish there were an onscreen version, for my middle aged eyes to use from across the room, but it's hardly a hill upon which I'd want to die because this preamp does so much so very well.
All for a reasonable $1899 Canadian, and - like the amp - available in silver or black. Rotel sent me black versions and they're handsome units, but I think I'd prefer the silver. Your mileage, of course, may vary.
Here are some of the preamp's specs:
Total Harmonic Distortion (THD) - (20Hz–20kHz) <0.002%
Frequency Response: Line Level Inputs: 10Hz - 100kHz ±0.1dB
Digital Inputs: 20Hz - 20kHz ±0.5dB
S/N Ratio (IHF "A" Weighted):
Line Level Inputs: 112dB
Digital Inputs: 108dB
Phono Input: 80dB
The RB-1590 is a beautiful companion for the preamp. While 200 or 250 watts seems more common, and is nothing to sneeze at, Rotel has upped the oomph ante to a whopping 350 watts per channel, into eight ohms, and the amp delivers its sound so cleanly - and loudly - that I swear I'm lucky not to have gone deaf during my listening sessions. The prodigious power can come in handy in a larger listening room (or commercial venue) or if you have less sensitive speakers that like to suck back power, and it's absolutely stunning if you merely like playing it LOUD! My cats would hightail it to quieter parts of the house - which were difficult to find - when I cranked the system.
I used both Definitive Technology and JBL speakers at various times during my tests and the only worry I had was that I'd turn them into little black, smoking rocks by the time I was through. It never happened, but the Rotels sure pushed them to perform! And they seemed to enjoy the workout.
Rotel uses custom made massive, twin, toroidal transformers as part of a power supply that includes eight British made BHC capacitors, which the company says improve high energy signal transients and dynamic bass performance even under the most difficult load conditions. It seems to work.
The company prides itself on not being fixated solely on power, however, and says the development of the RB-1590 also included extensive listening sessions to ensure that its awesome power is combined with nuance, detail, and overall musical performance. They laid out the circuits in true monoblock design (which means, basically, that the amp functions as two mono amps joined at the hip, to ensure maximum signal separation and stereo imaging) and the result must be heard to be appreciated. This is a beautiful amp that creates a marvelous listening experience.
Naturally, the amp includes XLR balanced and RCA input connections, and you also get two pairs of five-way speaker binding posts, a 12 volt trigger control, protection circuitry, a dual stage power-on relay and a chassis that can be rack-mounted.
The RB-1590 is also available in black or silver and retails for $3,299 Canadian. If that seems like a lot of money, listen to this beastie for a while and you won't want it pried out of your cold dead listening room.
Here are a few of the amp's relevant specs:
Continuous Power Output: 350W/Ch (All channels driven, 8 ohms)
Total Harmonic Distortion (THD): (20Hz–20kHz) <0.03%
Frequency Response: 10Hz - 100kHz ±0.5dB
S/N Ratio (IHF "A" Weighted): 120dB
For a source component, I used OPPO Digital's wonderful BDP-105 Universal Audiophile 3D Blu-ray Disc Player, connected via both RCA and XLR connections, separately. It was an excellent match because the OPPO plays pretty well anything imaginable, whether it be disc-based or as digital files, and does a marvelous job of it.
I auditioned a wide variety of music and movie sources to test the Rotel pair and found that it excelled with all, with clean and clear sound that's very involving. I could listen at high volumes for extended periods without getting tired (heck, it was more like an adrenaline boost!) though I did miss having surround sound for movies and multi-channel high resolution audio discs. Adding amps and switching to a surround preamp would change this, but each extra amp will require space: the amp measures 17 x 9.75 x 19.9 inches and weighs a whopping 84 pounds. But I reckon you'll die with a smile on your face!
You could also use the RB-1590 to power your main front channels and get lesser amps for the rest. It's best to have identical components all around, but I can see why someone would go this route, especially if most listening is to stereo sources.
As is traditional when I review equipment, the first disc I put through the Rotels was the 1990's remastering of The Who's Live at Leeds, which is the most dynamic CD I've heard and sounds almost as if it were recorded in the digital age rather than 1971. Fire up Magic Bus at the end of this disc, crank the Rotels and sit back; it'll become obvious to you quickly that this is a special system. Your neighbours might even start up a petition to make you turn it down, but don't pay any attention to them.
I also auditioned some of my favourite concert discs, including the Cream Reunion and Ray Charles at Montreux Blu-rays, both of which have stereo tracks that sound magnificent even when they're not played by the Rotels. And though I had to dumb them down to stereo, via the OPPO's decoding and remixing capabilities, I also reveled in the DVD-A of Les Brown and his Band of Renown's Session #55, The Who's Quadrophenia Live in London concert Blu-ray, and a variety of my beloved DVD-A and SACD discs - including Pink Floyd's Dark Side of the Moon, Elton John's very loud Goodbye Yellow Brick Road, the Doobies' Captain and Me, the stereo SACD of their Toulouse Street and some lossless, high resolution files I've downloaded over the years for testing purposes.
The soundstage is wide and deep, the highs are clean and crisp without being shrill and the bass is tight and deep without being boomy. The system also offers great clarity and refinement and didn't seem to care whether they were asked to play rock, classical, jazz, concerts, movies, or whatever. They just sat there, happily gobbling up whatever signal I fed them, giving me beautiful and bountiful sound in return, from the most glorious music to the most outrageous movie sound effects. Naturally, this performance is also affected by the source material, but I fed it good signals and the Rotels repaid me in kind.
In short (well, I guess that ship has sailed…), this is a wonderful pair of audio components that, given Rotel's history, should serve you well for many years, or at least until the neighbours show up with torches and pitchforks to force you to turn it down.
Copyright 2015 Jim Bray
Jim Bray's columns are available through the TechnoFile Syndicate.
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