September 2008 Reviewed by Howard Kneller	Outlaw Audio Model 7900 Multichannel Amplifier

Description Model: Model 7900 Price: $3499 USD Dimensions: 17.2"W x 9.5"H x 19.5"D Weight: 145 pounds Warranty: Five years parts and labor; 30-day satisfaction guarantee.	Features 300Wx7 into 8 ohms, 450Wx7 into 4 ohms (manufacturer rated) RCA inputs, fully balanced XLR inputs Automated input selection for RCA and XLR inputs Dual detachable 15A IEC power cords Remote trigger switch

I’d just reviewed a 150-pound home-theater rack, and my back was seriously contemplating the wisdom of my having agreed to review Outlaw Audio’s Model 7900 seven-channel power amplifier, which weighs only five pounds less. But there it was in my listening area, complete with the two 15A power cords (yes, you read that correctly) needed to operate it.

Well, my back might have said no, but the rest of me shouted an emphatic Yes! This behemoth of an amp is rated to put out 300W into 8 ohms or 450W into 4 ohms. And it gets better: The Model 7900 retails for $3499 -- not a lot of dough for the ability to drive some of the most power-hungry speakers out there. The fact that Outlaw Audio has a reputation of manufacturing high-value home-theater and stereo equipment only made me more eager get my hands on a 7900.

Description

On their website, Outlaw Audio states, only half-jokingly, that the class-AB Model 7900 has "enough power to weld a fender together at a bike shop in Orange County." Yes, its power rating of 300W for each of its seven channels is jaw-dropping. However, what’s even more incredible is that this rating is based not on a single channel operating flat out, but on all seven channels run simultaneously, with less than 0.05% distortion from 20Hz to 20kHz.

The 7900’s power supply is driven by two huge toroidal transformers. These and the seven massive internal heatsinks account for a good chunk of the Model 7900’s weight. Also, with 36,000µF of filter capacitance per amplifier module, the 7900 can store an enormous amount of power: even at the biggest climaxes, ample power will be available.

Aside from its monstrous power-output capabilities, the differential design of the Model 7900 uses common-mode rejection to reduce crosstalk (i.e., leaking of the signal between channels) to greater than -100dB, a level well below audibility. Additionally, the 7900’s slew rate of 50V/µs is twice that of many other amps. The slew rate is a measure of how fast the voltage rises from almost zero to almost full power -- or, in audiophile terms, the speed at which an amp can handle transients.

The 7900’s large size means that its spacious rear panel provides generous amounts of room around each speaker output and each single-ended RCA and balanced XLR input. The RCA inputs are "semi-balanced," which Outlaw claims provides a cleaner signal path than traditional RCA connections. Also, unlike some amplifiers, whose internal single-ended circuits are terminated with XLR connectors, the 7900’s XLRs are said to be fully balanced. Input selection is automatic: the 7900 detects what type of connectors you’re using. This is one of the many features of the 7900 that are typically found only on far more expensive amplifiers.

The rear panel also contains a ground terminal, a remote trigger switch, the two 15A AC inputs mentioned above, and, just as incredibly, two power switches to turn the amp off and on. There are no fuses -- an opto-coupled circuit closes down the 7900 when necessary. This type of switch performs the same function as a fuse, except that it uses an infrared beam of light rather than a mechanical actuator.

Setup

Usually, there’s little to say about setting up a power amplifier, but the Model 7900 is not a usual amp. First, just getting this giant out of its box and into my system was a two-man job. Second, there was zero chance that the 7900 was going onto my already overloaded, DIY isolation rack. I placed it on the floor in front of my system, a decidedly imperfect location.

For the 7900 to deliver its full rated output, Outlaw "strongly recommends" that its two 15A power cords be connected to separate, dedicated 15A circuits. I don’t have one dedicated 15A circuit for my system. I threw caution to the winds and plugged both cords into my Synergistic Research Power Cell power conditioner.

Much to my surprise, while the 7900 ran fairly warm, it never got nearly as hot as my B&K AVR-507 receiver, which also has class-AB amplifiers. Perhaps the B&K has fewer output transistors than the Outlaw. If so, this would force each transistor in the AVR-507 to carry more current than any single transistor in the Model 7900. Either way, the 7900 ran cooler than I’d thought it would.

Sound

It immediately became clear that the Outlaw Model 7900 was no muscle-bound oaf. Sure, it could shock and awe me with the gravest authority. However, it could also finesse the source signal like some of the very best, big-name home-theater amps, at a fraction of their price.

One of the best-sounding recordings I’ve heard is Seal’s Best: 1991-2004 (Warner Bros. 48882-2). The set comprises one DVD-Video and two DVD-Audio discs, one of the latter containing acoustic versions of many of Seal’s greatest songs. If you seek exceptional detail and microdynamic delicacy, seek no further: If there was ever a time for the 7900 to show its sensitive side, this was it.

"Crazy" (track 3), like most of the acoustic tracks, handily outshines the electric version. I could hear Seal’s hands move over the guitar, and his body’s movements against the guitar. The strings were tight and full-bodied, with excellent timbral accuracy. And the 7900 produced remarkably little background noise: everything was painted on a canvas of inky-black silence.

It soon became apparent that, no matter what music I played, the sound of the 7900 was remarkably balanced: neither warm nor cool, but absolutely neutral. While it would be difficult to mistake the Outlaw for a tube amp, this is not a criticism. The sound of the 7900 was much more crisp and sharp than that of tube amps, which can sometimes sound a bit soft and rounded. The 7900’s reproduction of music-only recordings was not what I expect to hear from most home-theater amplifiers. I can only wonder what improvements two dedicated AC lines and a pair of good aftermarket power cords would contribute to the 7900’s articulation of microdynamics and the lowering of its noise floor.

Out came Saving Private Ryan. The first scene of the beach landing at Normandy (chapters 2-4) is a sonic tour de force of mechanized warships, automatic gunfire, explosions, and butchery. Through the Model 7900, these sounds were so sharp and visceral that the punch of the explosions kept on surprising me, even though I’d played the scene again and again.

When I turned up the volume for these beach scenes as much as my speakers and neighbors could stand, the 7900 didn’t flinch, but just sat there doing its stuff as if in disdainful disbelief that I could even think that this exercise might cause it to break a sweat. Based on the 7900’s over-the-top power-output specifications, I wasn’t surprised. One Outlaw engineer told me that they still haven’t found a speaker that can make the 7900 clip.

Last came Basic, a military thriller starring John Travolta. Chapter 1 opens with an Army Ranger helicopter that enters from the right rear surround channel and proceeds to the front right channel in a way that typically makes visitors jump from their seats in disbelief. With the Model 7900, the sound was so clean and detailed that I could make out the tiniest nuances in the sound of the chopper’s blades, even as the overall impact of the soundscape was shockingly deep and powerful.

Comparison

I compared the Outlaw Model 7900 with my current reference, Halcro’s Logic MC50 five-channel amp ($5990). The Halcro, which I reviewed in April 2008, sounds cooler and cleaner, with breathtakingly crisp transients. The 7900 was an all-around great performer that presented a fuller bottom and more, well, oomph. All in all, I preferred the Halcro. However, others might want an amp like the 7900, which, with its sonic weight, can bully any kid on the block. That the 7900 costs little more than half as much as the Halcro might affect such a choice. Add to my sonic preference the modest size and electrically challenged nature of my listening area, and it should be no surprise that the Halcro will remain my reference amplifier. The Outlaw 7900 may simply be more amp than I need or can now accommodate.

It’s difficult to be critical of an amplifier that offers so much performance for so little money, but I wasn’t overly happy with the quality of Model 7900’s chassis. While the faceplate is very solid, the cover that fits over the top and sides is thin and, like the Halcro’s, resonates significantly when tapped. Most audiophiles would consider a chassis so eager to vibrate a bad thing that would likely prove detrimental to its sound. Nonetheless, here are two overachievers whose chassis resonate substantially. Go figure.

My other criticism is that, unlike the faceplates of some other multichannel amps, the 7900’s doesn’t include a set of LEDs that indicate that each channel is on and working properly. The more information you’re given about your amp’s performance, the better, and indicator lights can often warn you of an internal fault or anomaly in time for you to turn the amp off before any damage occurs.

But such criticisms are little more than nitpicking. The totally unexpected amount of hardware and level of performance offered by the 7900 for $3499 make it an out-and-out steal. To ask for anything more for the money would be unreasonable -- in fact, you won’t get it anywhere.

Conclusion

For some audiophiles, the ultimate purpose of an audio system is to ease their appreciation of the graceful, refined subtleties of a work such as Mozart’s Requiem, his final, unfinished composition. For others, it means shaking their neighbors’ paintings off their walls while watching Terminator 2. If you can provide the Model 7900 with the massive amounts of current that Outlaw recommends, it will take you well along the way to attaining either or both of these visions of sonic nirvana, and at a price that constitutes an obscene bargain.

My goal, however, was to produce this review. The toughest part of the job will be to get the Model 7900 back into its double box, then downstairs to my lobby to be picked up. The easy part will be giving the 7900 my recommendation, which I do without hesitation.

Manufacturer contact information:

Outlaw Audio, LLC
P.O. Box 975
Easton, MA 02334
Phone: (866) OUTLAWS (688-5297)

E-mail: info@outlawaudio.com
Website: www.outlawaudio.com

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