"... I will honestly confess that I've never yet cranked an amp to levels as uninhibited as the Level-2 Unico without being troubled by distortion. The amp was so clean and controlled that listener fatigue never became an issue. This was quite an incredible experience! The Level-2 had no difficulty with any musical genre or volume I chose to throw at it. It became child's play to identify the slightest system change effects such as a cable or support footer substitution. Not only was this a great analytical tool, it was a thoroughly involving, musical piece of kit with terrific immediacy and presence. Frankly, given the mere $400 cost difference, I was completely taken aback by the superiority of the Level-2 over the Level-1. I can only guess at the differences compared to the stocker. If I were contemplating upgrading an existing model or purchasing a modded unit, I'd spring for the Level-2. At only $2,295, Walter and Chris believe the Level-2 Unico bests the likes of the BAT or Mark Levinson integrated amps. I suspect a great deal of the noted sonic differences were due to the substitution of the stock opamps in the amplifier driver stage since greater resolution and high-frequency extension are two of the claimed characteristics of Burr-Brown's OPA-627..."
Paul Candy, December 2003, 6moons.com