David Vaughn

AT527NC Amplifier
Performance
Features
Ergonomics
Value

AT524NC Amplifier
Performance
Features
Ergonomics
Value

AT A GLANCE
Plus
Very powerful
Natural and balanced
Made in the U.S.A.
Minus
LEDs are too bright

THE VERDICT
The days of looking down on Class D amps are over.

Two and a half years ago, I reviewed my first ATI amplifier, and to say I was impressed would be an understatement. The ATI Signature AT6005 five-channel amp set a new benchmark for its designer, Morris Kessler—to the point where he put his John Hancock on the faceplate.

Last year, S&V editor-at-large Bob Ankosko sat down with Kessler to talk about his design philosophy over the years, and the subject of Class D amps was broached. Kessler mentioned that his current designs were all Class A/B, but he was following the developments of Class D very closely—though the initial efforts in this area didn’t meet his high standards because frequency response varied greatly as the impedance of the speaker changed. He hinted at the time that he may have finally found a Class D solution that he could deem acceptable, which turned out to be the latest Hypex Ncore modules.

Performance
Features
Build Quality
Value

AT A GLANCE
Plus
Powerful bass for a compact sub
Performs extremely well with music and movies
Minus
Lacks last half-octave of deep bass you can get from larger subs

THE VERDICT
If you’re limited on space but have adequate funding, this is the strongest-performing compact sub I’ve auditioned.

It’s another American business success story. A couple of kids, Jim Birch and Lucio Proni, begin building home loudspeakers during summer break in 1975. More than 40 years later, Jim and Lucio are still going strong, having seen JL Audio become one of the most respected consumer electronics brands in the world, branching out from the home to mobile and marine applications. I’ve experienced their products at some custom shops and have read glowing reviews of their subwoofers over the years. My favorite review was by my colleague Darryl Wilkinson, who said the company’s Fathom f212 sub could play a 20-hertz test tone loud enough to liquefy his bowels! High praise, indeed.