by Brent Butterworth


Back in '78, I remember verbally sparring with my aunt Esther over what constitutes good music. She suggested, oh , I don't know-- Perry Como or something. Being 16. Of course, I had to enlighten her on the superiority of adventurous new musicians like John McLaughlin. "Yeah?" she said. "Well, if he's so great how come I never heard of him?"
For a 16-year-old, at least, the implications of this statement were pretty heavy. Sure, Mariah Carey proves every day that fame does not indicate greatness, and my favorite bassist, Jamaaladeen Tacuma, has conclusively proven that relatively unknown artists can indeed kick ass. But there's something to be said for fame. A famous musician will, at the very least, put on a coherent performance, which isn't guaranteed when you come see the jazz group I play in. In the same way, you know a Krell amp is going to sound pretty good, but you don't know what your going to get from a Sherbourn amp.

The 5/1500 amplifier is Sherbourn's first product. If you look at the people behind the company, though you'll feel more comfortable. Sherbourn was founded by Ron Fone, the guy who dragged McIntosh into the home theater business, and Eugene Tang, who 's designed amps for NAD and countless other manufacturers. Considering who's behind this amplifier, you suspect it's going to be OK, but it's far more than that. It's a unique design and, by my reckoning, the least expensive 200-watt-per-channel, fiv e-channel amp available today.
A.This may be the least expensive 200-Watt-per-channel five-channel amp available today.
B.On back, there's a separate switch for each channel that activates a "soft clipping" feature.
The $1,750 5/1500 is unique in that each of its amps has its own complete power supply, with its own torodial transformer. I've seen two- and three-channel amps with discrete transformers for each channel, but I've never seen a five-channel amp designed this way. The advantage of this design is that the channels are completely independent--Heavy power demands in one channel don't affect the other channels at all.
There's a downside to this design, too--an amp with one big power supply for all channels can provide extra juice to one or two channels that are being driven especially hard, as long as the remaining channels aren't overly stressed. Some manufacturers even tout a single power supply as a special feature: Carver calls it "power steering."
With Pro Logic, it's impossible for all the channels to play loudly at the same time, so having a single power supply might be an advantage. But with Dolby Digital and DTS, it's possible (and as I've noticed, common) for all channels to play loudly at once. That's why I think Sherbourn's scheme is the best approach circa 1999, even though I've never noticed an audible advantage to having separate transformers for each channel. It also makes it extraordinarily simple for Sherbourn to offer versions with fewer channels: A two-channel version costs $1,000, and a three-channel version costs $1,300.
Each amplifier has eight output transistors, two 10,000-microFarad power-supply capacitors, and its own heatsink. The sinks are massive, and have a clear ventilation path, so the amp requires no fan. What a relief! Hey, amp designers, can we get past this idea that a five-channel amp has to have a fan?
TESTING SYSTEMAerial Acoustics 7B, CC-3, and SR-3 speakers, NHT SuperTwo, SuperOne, and SuperZero speakers, Acurus ACT3 pre/pro, Kimber 4TC speaker cables, DiMarzio interconnects, Sony DVP-S3000 DVD player. It doesn't and what good does all that tweaking on your designs do if you hang a 50-dB SPL noise source on the side of your chasis? It's like having that guy who plays Newman on Seinfeld sitting next to you after he just ran up the stairs.
The front panel has a blue LED "on" indicator for each channel, plus a power switch. On the back, there are sturdy, chasis-mount RCA inputs, a DB-25 six-channel input, conventional five-way speaker-cable binding posts, and several switches. A separate switch for each channel activates a "soft clipping" feature. Soft clipping lets the amp overload in a way that's more sonically benign than the usual harshness you get when an amp clips. Two more switches let you bridge the two right channels and/or the two left channels for 400 watts total output per bridged pair. Of course, you don't need more than 200 watts per chan nel, unless maybe you're going to use the 5/1500 to drive a subwoofer or one of those refrigerator-sized Jensen or Cerwin Vega speakers with a 15-inch woofer.
HIGHLIGHTS* The least expensive 5-by 200-watt amp we've found.
* Nice extra features: a DB-25 input and bridging capability

* Very competitive sound
CFG Labs measures: Sherbourn 5/1500 Amplifier This chart shows the power output versus total harmonic distortion plus noise of the 5/1500's left amplifier channel, with soft clipping on and driving an 8Q load. The amp begins clipping at 0.01 4% THD+N and 141.2 wafts, and reaches 1 % THD+N at 202.3 wafts, Into 4 92, the amp begins clipping at 276.2 wafts/0.021% THD+N and reaches 1% THD+N at 359.9 watts. Into 2 K2, the amp begins clipping at 334.2 wafts/0.01 8% THD+N, and reaches I % THD+N at 481.5 watts. The numbers are the same when driving all channels, although some of the channels blew their fuses when we tried this with a 2i2 load. The amplifier's frequency response rolled off no more than 0.2 dB from 20 Hz to 20 kHz. The response only dropped to -0-675 dB at 1 0 Hz and to -1.2 at 50 Hz. Crosstalk was -1 17.5 dB from left to right and -1 1 0 from right to left. These are all very good measurements.-MW/BB

Assistant editor Joe Hageman and I listened to the 5/1500 for about a week, using high end speakers from Aerial Acoustics and a moderately priced set of NHTs. We liked the soundright away, even after spending the previous couple of months listening to ADA's $6,995 MPA-501 amp. Even driving the Aerials--a $7,900 speaker system--the 5/1500 didn't sound out of place. With no powered subwoofer in the system, the 5/1500 had to provide all the floor-shaking on its own, and it never even came close to losi ng control to the Aerial 7Bs' woofers. The bass always sounded tight and tuneful, there were no noticeable colorations in the midrange or treble, and the amp never seemed to run out of juice. Last month, in my review of the MPA-501, I described ATI's $1 ,599 AT1505 amp as being "as good as anyone really needs," and the 5/1500 falls into the same category--this is the level of performance where, in my opinion, any flaws are insignificant and won't detract in any way from your enjoyment of a movie or a CD.
I knew after a few days that the 5/1500's sound could keep me happy, but how would it compare to other amps int its price range? To find out, I compared the 5/1500 to the ATI AT1505 in a long, Saturday afternoon listening session.
The difference between the two amps is so minimal you could pull your hair out trying to nail it down, but after about a dozen DVDs and CDs, I finally got it. The 5/1500 produces slightly tighter, better controlled bass than the AT1505, while the AT15 05 has a somewhat smoother, more natural-sounding extreme treble. Those two advantages cancel each other out, I guess, but the 5/1500 also seems to have a slightly more present and pronounced midrange. Whether that makes it better or worse than the AT15 05 depends on the recording. On the eagles' DTS CD Hell Freezes Over, the 5/150's sound brought out the details in the acoustic guitars better. But on Marvin Gaye's DTS CD Forever Young, the voices sounded a little smootherwith the AT1505. I went back and fourth between the two for hours and, failing to develop a consistent preference for one or the other, I realized I was spending my entire Saturday afternoon comparing amps in a windowless room and promptly got the hell out oof there.
There's a wealth of really good, relatively affordable multichannel amps with 150-plus watts per channel, including the 5/1500, the AT1505, and the ADA PTM-6150. The 5/1500 sounds as good as either of those, and it's got 50 watts more power (that's 1. 25 dB of extra headroom) per channel and a few extra features to boot. I think it's today's best value in a five-channel amp. Sure, I know people who might balk at spending $1,750 on a product from a company they've never heard of, but luckily for Sherb ourn, my aunt Esther's not into home theater...