July 2002

Cause and Effect

What we call sound is a product of acoustic energy and its effect on our hearing apparatus. Acoustic energy does not produce sound alone -- you need a set of ears too. It’s the old tree falling in the forest thing.

I got to thinking about this while observing a recent discussion among the SoundStage! staff. It was submitted that any sound system that makes a recording sound "live" must be inherently distorted, because recordings have distortion. Now, I agree with the conclusion of this argument -- if the recording is distorted, only complementary distortion can make it sound live -- but I disagree with the premise that recordings are necessarily distorted. Just as a tree that doesn't fall makes no sound, how can a recording that isn’t played back, thereby producing no sound waves, have distortion?

Looked at this way, you see how a recording’s quality can be evaluated only in the context of the playback equipment. The same holds true for hardware evaluations.

A senior audio-equipment engineer for one of the world’s most-respected manufacturers told me that a significant difference between their new and old products is how they complement recordings of their day. That is, their playback devices (e.g., amps, preamps, tuners) have been engineered to complement the recording side of the chain. As the recording methods have changed, their playback devices have been redesigned to keep pace. The message was that their current products are not hands-down superior to their 30-year-old products. Indeed, he seemed to all but say that the newer products aren’t inherently better at all. (Obviously, this isn’t completely true of equipment design or we’d be going in circles with respect to fidelity. Many audiophiles do take it as a given that audio recording/playback fidelity has been circular, and argue instead over how just how much forward movement there’s been.) At any rate, the significant truth for the moment is that the performance of the device has meaning only in the context of the recording/playback system of which it’s a part.

This makes the job of choosing a playback system, or an individual component, a bit easier. You have the whole recording/playback chain and your ears with which to do it. There is no contemplating how to discover the inherent goodness or badness of the playback elements, because there is no such thing. Just listen. Those systems or components that sound bad with most of your recordings you can forget about. The systems or components that make the largest number of your recordings sound real -- if real is your bag -- then buy them. If you want a warm and cozy sound, that’s out there too. Maybe you think analytical is the mark of quality -- you’re still impressed with the high-end, ‘80s digital ideal. Go for it. Maybe you just listen to your butt and let your brain follow. Now, that’s not a bad approach at all!

...Dennis Hartwick
dennis@soundstage.com

Rotel RB-1090 Stereo Amplifier

Lately, my own butt has been boogying to Rotel’s RB-1090 stereo amplifier, rated at 380Wpc into 8 ohms and 700Wpc into 4 ohms. Rotel says it can deliver peaks of more than 1000W into 2 ohms. Inside there are two 1.25kVA custom-made toroidal transformers. The chassis is a sizable 17 3/8" x 9.5 x 15 3/4". In all, this unit is a beast -- with heatsinks that can maim!

Putting safety first, I’d like to point out that lots of amplifier heatsinks are sharp, and despite the danger this poses, I suspect they are left sharp because squared angles are more attractive than rounded ones. Still, I’d love to see more amplifiers with rounded corners. Thankfully for this amp, Rotel provides two built-in castors on the rear underside of the unit -- a nice touch. I was able to get out of the way of the heatsinks and roll the RB-1090's 84 pounds to its resting place between my speakers.

Rotel provides both standard and balanced inputs on the RB-1090. I’ve tried running balanced in a number of systems, and I have heard no difference once loudness levels between the single-ended inputs and the balanced inputs are equalized. Therefore, I used the single-ended inputs here. On the back side there is also an IEC power-cord receptacle should you wish to tweak your RB-1090 with an after-market cord. I used the amp with the supplied cord.

Two sets of speaker outputs are provided, good for biwiring -- which sometimes sounds better -- or for connecting two pair of speakers. When doing the latter, Rotel warns that you must use speakers that have an impedance no lower than 8 ohms. This will have the amp pushing into a 4-ohm load, which is fine. It’s below 2-ohm territory when the amp will shut itself down. If this happens, a left- and/or right-channel warning light comes on, and you are supposed to shut the amp off and wait a few minutes before resuming normal operation. Shutdown will also occur if the amp gets too hot due to "extreme or faulty operating conditions."

My speakers are Von Schweikert VR-5s -- a reasonable load, but they do like power. Source components on the analog side include a McIntosh C38 preamplifier used as a phono stage and a Grado Reference cartridge/Linn Itok LV II tonearm/Linn Sondek LP12 turntable/Naim Armageddon power supply analog rig. For digital, I use a Sony DVPS-7700 DVD player as a transport, which feeds a Meridian 568 surround-sound processor used as a digital-to-analog converter. For preamplification there is my Placette Audio Line-Stage Preamp. Cabling includes an assortment from Silver Audio, Monster Cable, TARA Labs, and Custom House. Power conditioning is from Monster Cable and XS Technologies.

If you do give the RB-1090 a listen, keep in mind that it needs more than a few days to break in. I let it amplify continuously for over two weeks before any lengthy listening, and it was substantially improved for the practice.

Once settled in, the RB-1090 had strengths that were readily apparent. The bass the amp brought to my system resonated my core, or it bounced lively and taut, as the source demanded. If you check out "Senseless Apprentice" from Nirvana’s In Utero [DGCD 24607], you’ll hear a rock recording with uncharacteristically raw sound, courtesy of recording engineer Steve Albini. I don’t know if you’ll be able to get through the song -- it helps to be less than 25 years old and very angst-ridden -- but you need go no further than the first five seconds to hear a drum recording that seems to have no dynamic limiting. Through my system, at loud levels, the Rotel amp missed only a bit at making the bass-drum strikes pound against my chest in a realistic fashion. Believe it or not, power may have been the limiting factor here; my VR-5 speakers want a lot of it to reproduce a drum kit, even though I seriously doubt they could ever do so realistically.

Another Steve Albini recording that’s terrifically transparent and dynamic is The Breeders’ debut, Pod [4AD/Elektra 61331]. I missed only a touch of sweetness in the low notes of the electric bass guitar through the Rotel amp, something you wouldn’t know was missing until you heard the recording through better, and likely more expensive, amps. Consequently, the bass was a touch less tuneful. This harmonic richness -- or musicality or sweetness -- was slightly compromised throughout the frequency spectrum. That said, listening to Pink Floyd’s "Time" from Dark Side of the Moon [EMI 679180] while typing this, I’m easily distracted by the Rotel’s engaging performance.

The RB-1090 focuses sound as assuredly as I’ve heard at any price. There’s no wavering of image placement. Such wavering is akin to viewing images through heat rising from the road. Admittedly, it’s rare to hear this problem on even a $600 surround receiver -- provided the speakers are properly matched -- but it does sometimes rear its ugly head. I’ve heard such wavering from a $3000 preamplifier, for instance. Blissfully taking in the female vocal from the previously mentioned Pink Floyd track, a vocal which is recessed in the soundstage, I noted that the singer’s location was never in doubt through the Rotel RB-1090.

I was also impressed with the RB-1090’s ability to let me hear detail, as I found nearly every nuance of sound simply hanging in space for my consideration -- the mark of a high-resolution system. On "Time" again from Dark Side of The Moon, after the bells but before the singing there is a distorted sound placed center-stage, which is like an overtone to whatever the electric bass is doing. The distortion of this sound has lots of static-like texture. With the Rotel amp you can clearly hear the crackling amidst all else that’s happening. With a lesser amp, you would not be able to hone in on such a detail so easily. Indeed, for many listeners, this amp will reveal a wealth of information that they haven’t heard before.

As for dimensionality, I’ve never heard better for the money. In a perfect world, performers and their instruments have a palpable presence and can sound as if they’re anywhere in the room. While no two-to-seven-channel system can do the latter, I have experienced two-channel systems that can do the former. This aspect of reproduction, known as dimensionality, was the best I’ve heard in this price class. It fell short of the best, rendering Margo Timmins’ vocal flatter than I know it can sound on the Cowboy Junkies’ "Good Friday," from Miles from Our Home [Geffen 25201].

Is the RB-1090 perfect? No. But no amp near its price is. The Rotel’s sound can be likened in some ways to a car windshield that has been hand-cleaned several hours earlier. It’s extremely clear, yet there is the slightest bit that does not quite shine through like it originally did when it was new. My reference amps are like the new windshield. They offer crystal-clear sound that is more natural in just about every respect. The Bel Canto amps, with 400 watts and 60 amps peak current capability per amplifier, offered a more full-bodied and powerful presentation too. The Rotel’s bass is also just a notch looser and not quite as robust.

Through all of my listening, the RB-1090’s dynamics were impressive by any measure, and they were definitive for their price point. You’re looking at more than twice the price to get something that’s substantially better and maintains so much muscle. With the RB-1090, you might not know what you’re missing if you never go back and compare it against a pricier reference. In fact, if the Rotel amp were inserted into my system on the sly, I don’t think I’d pick up on it right away.

Truly, the Rotel RB-1090 is noteworthy for its power output and sound quality, and I hadn’t mentioned that it’s a handsome beast to boot -- all for $1999 clams. If the Rotel RB-1090 is in your budget, or even if you were thinking to spend a thousand dollars more, you’d do well to audition it. Perhaps you could better this amp if you could give up the power with, say, a very sensitive pair of speakers, but the RB-1090's combination of traits is difficult to match.

...Dennis Hartwick
dennis@soundstage.com

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