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ATI AT1502 Amplifier Review

Audio Adventure Magazine
by Tony Rago

A Historical Return

In their early teens, at the beginning of their long audio friendship, Mike Pontelle and Morris Kessler built amps in Kessler's bedroom. In 1969, Kessler formed SAE and a year later Pontelle became his partner. For almost two decades, they made some of the best known home audio amplifiers.

In the early Seventies, if one wanted the best in solid-state amplification, SAE came to mind. Known then internationally as purveyors of open and musical products, SAE lingers in the minds of audiophiles old enough to remember as a company that really produced. My cousin's SAE amp had so much power he ran a block party with it. And these amps were so popular, they took Japan by storm way before single-ended tube amps became retro-cool in the land of the rising Sun.

ati at1502 audio power amplifier

Kessler sold SAE in 1988 and Pontelle worked with other audio companies. Then in June of 1994 they became a team again - this time under the banner of Amplifier Technologies, Inc., or ATI.

Founded on such a heritage, ATI believes their experience in making superb sounding amps is reflected in their current designs. The company sells several amps -- including the $795 150-watt two-channel stereo amp called the AT1502 reviewed here. (The 1506, identical in looks, is pictured.) Aren't you itching to find out if ATI is really going to live up to their musical history?

Small But Spunky

The exterior bespeaks strength. Small, chunky, the AT 1502 has extremely large heatsinks. Heatsinks this big and thick are usually found on amps costing many times this one's modest price. Inside, you will find a very large toroid transformer, which ATI winds and fully complementary circuitry. The dual-complementary differential input devices (operated in Class A up to this point) are then followed by six Toshiba bipolars per channel.

The AT 1502 has unique fuse-fault indicators on the top cover. The rear has gold-plated single-ended inputs and plastic covered binding posts. (More on this later.)

Putting out 150 watts per channel into 8 ohms and 225 into a 4-ohm load and with a specified damping factor greater than 1,000 (the specs don't specify the frequency) and dynamic headroom of more than 2db, the AT1502 can safely be expected to drive and control most speakers. The Audio Physic Spark (reviewed this issue), with its rated sensitivity of 86db and a nominal impedance of 4 ohms, presented a fair test. This is not a forgiving speaker and will take the measure of an amp's treble range. The Spark can dig deep enough in the lower octaves, but not in terms of output. Still, what we really need to know is how good the midbass is -- this speaker sounds thin in the midbass with a weak amp and bloated with an amp with little control.

Liquid Fire

To examine an audio product's performance, I first use unamplified music recorded in a real acoustic space (rather than a studio). Let's give Mozart's Piano Concertos (K 271,595-- Chesky CD156) a spin, with Nicola Frisardi on piano with the Mozarteum Orchester Salzburg. This is a reverberant recording, something Chesky is famous for. The ATI amp allowed wonderful liquid textures to evolve from Frisardi's piano and the sounding board resonated realistically. Harmonics swelled within the hall acoustic, creating, or recreating, a very lifelike sound and feeling. Strings had natural grain. If you listen carefully, you notice just the least amount of air missing from the very highest part of the treble range, which translates into somewhat thin violins and flutes. Not so thin as to hamper the timbres in any appreciable way, though. Very few amps get this part of the music spectrum fight. The far more costly Sonic Frontiers Power 1 and 2 amps do, as does the solid-state Clayton S-40. But you can buy the AT 1502 and a pair of peachy keen speakers for the price of those amps. All in all, the AT1502 didn't fall far behind the best in the house. It would be a difficult choice between the similarly priced Class6 C-100 and the ATI. Ergonomics might be the deciding factor.

Such a powerful amp should have dynamic fortitude and I wasn't disappointed. To give it the best test, I listened to vocal arrangements, since there are few more dynamic instruments than the human voice. Listen to Tim Burton' s The Nightmare Before Christmas (Walt Disney Records 60855-7) just for the host of voices. Check out "Making Christmas" for a whole party of human timbres. The AT1502 allowed the crowd to appear before me. The Spark excels in imaging and the ATI loved this. Or did the Spark love the ATI? The dynamic gradations were very involving as were the rhythmic movements. Pace and dynamics are so closely connected that one can hardly be done well without the other. The ATI amp performed well on both scores with this CD and any other (ancillary equipment: Pioneer PD-65, AMC CVT 1030 preamp).

Rock Of Ages

You want rock? Okay. Big Head Todd & The Monsters, Letters To Cleo and Catherine were pumped out with power. I hadn't expected the Sparks to sound that good with this kind of program material. This amp will certainly appeal to headbangers. Excellent! Bass guitar, not to mention kick drum, can set the foundation for some really serious rockin'. The amp's power in the midbass allowed the Sparks to really swing with rock and blues.

The midbass was rich and lower bass was them without being mushy. Electric guitar leads were clean and crisp and had the shock factor that rock and electric blues has. Pink Floyd's Wish ~u Were Here (Sony Gold Super Bit Mapped version CK53753), specifically "Have A Cigar," showed off the Fender Strat playing of David Gilmour. The Gibsonloving B.B. King shone on Blues Summit (MCA MCAD- 10710). I came away with a firm respect for the AT 1502's muscle and finesse.

Singin ' The Blues

Curious about audiophile-type music? Then let's go to the approved Famous Blue Raincoat (Attic ACDM 1227). Bass is warm and inviting. Listen to "First We Take Manhattan" and you will hear wonderful saxophone timbres. The AT1502 clearly enjoyed resolving the subtle nuances of Jennifer Warnes' great voice, even in duet with Leonard Cohen on "Joan Of Arc." And if you're a blues fan, you'll be sincerely moved by B.B. King's unique guitar style as he jams with John Lee Hooker in "You Shook Me" on Blues Summit. If you don't enjoy King playing Lucille (his Gibson), then how can you count yourself a real blues fan? Now listen to the lovely Etta James singing with King on "There's Something On My Mind." Her voice will melt your soul -- if you listen to it with the AT 1502 in your system. Soundstage? Oh you audiophile perfectionists! Well, at first, I thought the soundstage wasn't well layered in depth, but adding the AMC DAC8 to the Pioneer CD player changed things immensely. Now the soundstage became more airy and open. Something SAE was always famous for. Yes, the ATI has, in many ways, lived up to its heritage.

The Bind That Breaks

Now we come to the one problem. Binding posts. Not that they aren't sturdy. They're positively husky. But -- there's no provision for spade lugs. Rats! You're stuck with bananas and not the eating kind. Or bare wire. I used barn Monster wire (16 awg) to hook the Sparks up. ATI does this in accordance with EC65 regulations, the standard outside the U.S. Also in the overseas market, bananas are more popular than spades. But I'm a spade kind of man. Mike Pontelle says that ATI is considering changing this. So speak up, fans. If enough of you let ATI know that you checked out this amp -- which you most certainly should do and found the sound top-notch -- which you probably will, but you want to use spades, maybe they will furnish the AT 1502 with different speaker binding posts.

History Repeats Itself

Summing up: the AT1502 represents a bargain at its price. You can buy a fancier looking amp. But if sound is your thing, the AT1502 won't disappoint. Want substantially better sound than this amp provides? Plan on dipping deep into the kids' college fund. It will be really hard to find a better sounding amp for under twice the AT1502's price.

ATI does its history proud with the AT1502. And it does right by savvy high-end consumers, too. Looking for a low-priced amp that is built to last, has plenty of power and delivers subtle musical details along with dynamic strength? Look no further than the AT1502, brought to you by a company that knows how to build amps. A company that knows where it came from and builds on that legacy. Welcome back, guys.