August 2003 Reviewed by Anthony Di Marco	Sunfire Ultimate Surround-Sound Receiver

Description Model: Sunfire Ultimate Surround-Sound Receiver Price: $4195 USD Dimensions: 17"W x 5.75"H x 16.5"D Weight: 35 pounds Warranty: Two years parts and labor Features Dolby Pro Logic II, Dolby Digital, Dolby Digital EX, DTS, DTS-ES, and DTS Neo:6 decoding Tracking Downconverter power amplifier Two channels are software-configurable to drive back surrounds, second zone, or side-axis channels

Features (cont'd) Preamp outputs for all seven channels Auto signal sensing Carver Holographic Imaging Second zone FM/AM tuner with 40 presets Carver Dynamic FM Noise Reduction circuit HDTV-compatible component-video inputs MM phono input Eight-channel analog input for DVD-Audio and SACD Three subwoofer outputs Flash ROM memory software-update capability IEEE1394 FireWire expansion port Two-channel source-direct mode

The audio/video receiver has endured its share of criticism over the years. Placing the preamplifier, amplifier, and tuner within one chassis was traditionally considered a huge compromise of fidelity and build quality. Increased levels of internal noise due to crammed circuit design, puny power supplies, and inferior parts quality made the receiver taboo in purist circles. To a large extent, though, all that has changed.

The introduction of surround sound and the need to converge stereo and multichannel listening into one system has given the receiver a second chance to prove its value. Over the past several years, such companies as B&K, Denon, and Onkyo have invested vast amounts of engineering resources into making the receiver a product that even a jaded audiophile could enjoy. Higher-quality parts, highly efficient manufacturing techniques, and robust amplifiers have enabled these one-box solutions to handle sensitive low-level audio and video signals with very little tradeoff in fidelity.

The new kid is powerful

Bob Carver has a fondness for designing hugely powerful amplifiers housed in small boxes. It stands to reason that his entry into the receiver market should follow suit. The power output of the $4195 Ultimate Receiver is rated at 200W to each of its seven channels into 8 ohms, 400W into 4 ohms. But how the Ultimate makes such power requires a bit of explaining, so I contacted Sunfire engineer Alan Cooney to get the scoop.

Stable, high-power amplifier designs typically require huge power supplies, which not only take up space but give off large quantities of heat. Heat is no friend to sensitive electronics; over time, it can limit an audio component’s reliability.

Low heat is an alleged benefit of Bob Carver’s Tracking Downconverter power supply. By way of a device called a "comparator," the incoming music waveform is compared to the power supply’s rail voltage, and adjusts the demand for power as required by the music. But low heat is only one side benefit of this design. The main benefit of the Tracking Downconverter is its supposed ability to allow an amplifier to simultaneously deliver high current and high voltage.

All amplifiers have output transistors. An output transistor delivers power to an amplifier’s speaker output and, ultimately, to a loudspeaker. Think of a transistor as a "gate" that allows only a certain amount of power through to the speaker. Power (wattage) is a combination of current (amps) and voltage (volts): W=C*V. Transistors can handle only a certain amount of power safely. Typically, an amplifier’s power supply has to keep its voltage capacity at a high level because it can’t predict what the incoming musical waveform will require. If the music requires more than the rail voltage, then an amplifier’s output will distort.

A side effect of keeping voltage at a high level is that it leaves less room for current when it comes time for the output transistors to deliver power to the speakers. Therefore, a power supply that has to keep current idling at, say, 50V will have the capacity to deliver only four amps of current through a 200W transistor. By comparison, Carver’s Tracking Downconverter keeps voltage idling at around 6V and uses the comparator to dynamically track the incoming signal. This allows the supply of current and voltage to vary depending on the soundtrack’s demand while staying within the transistor’s wattage capability. And since the power-supply voltage isn’t idling at a high level, current output isn’t restricted.

Show me what you got, kid

The Sunfire’s processing suite includes Dolby Pro Logic II, Dolby Digital, Dolby Digital EX, DTS, DTS-ES, and DTS Neo:6. Its setup and layout are fairly straightforward. The rear panel is, for the most part, logically laid-out -- I had no problem making RCA connections even when they had to be done by touch, but the speaker connections are awkwardly placed above the signal connections and the power cord. It took some jockeying of cables to make sure the connections were secure and not under stress. Five-way binding posts are of the plastic variety and too crowded for securing spades. Although the holes in each post will accept pin-style terminations, it took some effort to thread bare 16-gauge wire through them. I found banana plugs to be the best choice.

The remote, a Sunfire-programmed version of the Home Theater Master MX-500, is extremely easy to operate. The very intuitive user interface allows the user to rename labels and program devices by accessing preloaded device codes. Users can also employ the remote’s learning capabilities to store infrared signals from another device’s remote. The remote’s backlighting can be turned on and off. (My B&K AVR305 remote, a version of Home Theater Master’s SL-9000, requires the user to wait for the backlight to time out, which can be annoying when you’re sitting in the dark trying to watch a movie.) Users don’t need to worry about remembering which button they’re currently programming -- during the learning process, the Sunfire’s remote prompts the user with the name of each button’s function.

One feature I absolutely loved was the Sunfire’s software-upgrade capability. During my time with the Ultimate, I upgraded to firmware revisions 3.06 and 3.09 (as of this writing, Sunfire has made available a 3.11 version). Loading the firmware upgrades can be done via a CD-ROM, or files downloaded from the company’s website. I preferred the disc approach, but if you have an RS-232 cable, loading the website file with a laptop is just as easy.

A feature unique to the Ultimate came in handy. If you need only five channels of amplification, you can choose to redirect two channels of the Sunfire’s seven-channel amplifier to drive the receiver’s second zone! There are no wires to splice or warranties to void. All you have to do is set the appropriate software switch in the menu system.

The kid performs

I was genuinely impressed by the size and density of the Sunfire’s surround image. The crisp sound design of Jimmy Neutron: Boy Genius stretched out beyond the confines of my living-room walls and well beyond the loudspeaker baffles. Voices and subtle atmospheric effects displayed a weightless quality that seemed to appear out of thin air. With the Sunfire at the helm, my speaker system effectively disappeared. Much of this air and detail could be attributed to the Sunfire’s very low noise floor -- I heard no humming, buzzing, or hissing through my speakers. By comparison, my B&K AVR305 was slightly noisier, with a subtle hum apparent in all speakers.

The Sunfire’s bass quality out of both my Canton and Dynaudio speaker systems was breathtaking. Solid low-frequency rumble and attack were apparent in the Omaha Beach scene in Saving Private Ryan. Also impressive was the Sunfire’s ability to separate elements in a sound mix and place them solidly in the 5.1 image. The ricochet of bullets off of the steel tank blockades on the beach, the repeated fire of artillery, and human voices -- all took their places in the action without being overwhelmed by larger sounds, such as explosions. Nor did I hear any evidence of congestion. Massed sound effects and voices never sounded clumped together, and bass was nicely extended -- a good indication that the Sunfire’s 200W rating was not just hype.

The Sunfire exhibited a very natural, smooth sound with just a touch of sweetness in the midrange and high frequencies. Voices from The Emperor’s Club and Rabbit-Proof Fence had a velvety quality that didn’t get in the way of detail. Voices took on a very warm and inviting tonality, and high frequencies were weightless and vibrant. The Bee Dome sequence in X-Files: Fight the Future (chapter 11) was completely devoid of harshness, while the scene’s copious high frequencies extended cleanly beyond what my ears could perceive.

Playing Telarc’s new SACD release of John Pizzarelli’s Live at Birdland [SACD-63577] was rich and alluring. Voices hung seductively in midair within the smoky atmosphere of the nightclub. The snap of rim shots surprised me without making me wince, and Pizzarelli’s guitar playing was simply gorgeous. The experience was so relaxing and so involving that it lulled me into an almost catatonic state. I lost track of time and everything around me. It was exactly what I expected from excellent multichannel playback.

The Ultimate Receiver played two-channel music with the same broad soundstage stretching across the front two speakers. Pairing the Sunfire with the Canton speakers generated a very open and crisp sound, with a touch of tube-like warmth. I listened to Star Wars: Episode 2-- Attack of the Clones [Sony Classical 89932] from beginning to end with crescendos topping 105dB, with no complaints from the Sunfire.

The Dynaudio Audiences were much sweeter, with a distinct clarity and presence in the midrange. The Sunfire-Dynaudio combination demonstrated more midbass weight than the Sunfire-Canton duo could match. This characteristic conveyed more realism in voices and stringed instruments such as guitars and cello. The guitar on Jesse Cook’s "Luna Llena" (Gravity [ND-63037]) had body and a three-dimensional presence in the soundstage. Lower bass sounded less defined, but was nonetheless warm and full.

"Adios Hermanos," from Paul Simon’s Songs from the Capeman [Warner Bros. 46814], is a great test for vocal weight, soundstage depth, and palpability. The Sunfire made each voice stand out from the others in a relatively deep and consistent soundstage.

Not surprising, the Sunfire’s darker-than-neutral nature matched up better with sources that edged toward the analytical and bright. But while the Sunfire did add sweetness to the mildly analytical Arcam FMJ 23T CD player, it didn’t completely cover up the harshness of my Panasonic DVD-RP82S DVD player.

This dark sound did seem to affect how the Sunfire handled extreme high frequencies. For example, I love hearing the overtones that follow the metal clang in Jack Johnson’s "Posters" (Brushfire Fairytales [Universal 860994]). This particular sound should hang in the air a bit after the initial metallic impact, then gently disappear into the room. With the Sunfire, the decay trailed off almost immediately.

A little competition

The question that everyone has been asking is how the $4195 Sunfire Ultimate stacked up against my $2998 B&K AVR305. (But keep in mind that the Sunfire compares more closely to the AVR307/507 in terms of total number of amplifier channels and retail price.)

The B&K easily eclipses the Sunfire in overall build quality and solidity. Call me superficial, but the B&K’s fit’n’finish is more commensurate with what I would expect from a product costing $3000 to $4000. It’s not that the Sunfire is badly assembled -- on the contrary, its chassis is very solid and well-finished. What hurt the perceived quality of the Sunfire were its thin chassis, less robust speaker connections, mere two-year warranty, and a brushed finish that was sensitive to scuffs and scratches. The B&K’s powder-coated steel skin, thick aluminum faceplate, and heavy-duty speaker posts look much more durable. And its five-year warranty, though not an absolute guarantee of reliability, shows a stronger commitment to the product over time. I concede, however, that the Sunfire’s blue display and yellow buttons look much more impressive in a darkened room.

The Sunfire had an intoxicating sound that encouraged long listening sessions. It allowed me to enjoy my music collection rather than analyze it. The B&K is more neutral; it injects no sweetness or seductive quality into the sound and, as a result, does not affect the personalities of source components. If a CD player is laid-back or mellow, bright or etched, the B&K presents it as such; the Sunfire’s added warmth made the B&K sound a tad faster and more dynamic to my ear. The Sunfire’s bass had a rounded, warmer tonality; the B&K’s bass was punchier and more taut.

One could argue that the Sunfire is more powerful than the B&K -- and, on paper, it is. I was, however, unable to get either the B&K or the Sunfire to clip while driving the full-range Dynaudio Audience system in my medium-sized room. My guess is that either product will easily drive most systems without breaking a sweat. The B&K does get quite hot during intense operation. By comparison, the Sunfire stayed cool no matter how high I pushed the volume.

The Ultimate Receiver trounces the AVR305 in terms of upgrade capability. I’m not sure what B&K has done with their newer receivers, but my AVR305 requires an updated "controller" card for installing new revisions and bug fixes. The card can be swapped out only by a qualified technician, who must open the unit and replace a small circuit board. With the Sunfire, all you do is download the software from their website or call for a CD-ROM.

Connectivity and operability were pretty much a wash between the two. While the Sunfire’s menu system was slightly less complicated, the B&K’s rear panel was roomier and more logically laid-out. I could also access the B&K’s menus via the front panel. Misplace the Sunfire’s remote and you’re out of luck. And speaking of remotes -- while the Sunfire’s slick MX-500 easily beat out the AVR305’s older SL-9000, the current 500 series from B&K includes a more flexible version of Home Theater Master’s MX-700.

You’ve come a long way, baby

Sunfire’s Ultimate Receiver is a fine example of why even those considering separates should give the receiver another chance. Like the B&K AVR305, the Sunfire is a formidable product that does not give up performance to separate boxes. The only things that keep it from being a home run are its surprisingly short two-year warranty and construction that just misses the mark. That said, the Ultimate Receiver’s weight and size belie the muscle and technology that lurk below its contemporary exterior. It is extremely easy to use, and a joy to listen to when playing back favorite movies.

Manufacturer contact information:

Sunfire Corporation
1920 Bickford Avenue
P.O. Box 1589
Snohomish, WA 98290
Phone: (425) 335-4748
Fax: (425) 335-4746

Website: www.sunfire.com

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