I was given a NL-10 by a dealer for an extended home audition. It was an unopened box, brand new amp. I plugged it into Satellite radio for one week 24/7 to break it in at a medium low volume and went to Florida for a week.
I got home and started my listening and it was a total disappointment. No depth or width, and a surprising lack of dynamics. It sounded so flat that I called the dealer and he came over and listened and said there must be something wrong with the amp. But my impression was so negative I never asked for another to audition.
The drag was that I really wanted to love this amp. Everything I had read from reviews to comments on Audiogon made me want it. It just didn't sound good to me.
My system was/is Pass x-1 pre, JM Lab MIni-Utopias, JM Lab Sub-Utopia, Siltech LS100 cables, Purist Audio Venustas ICs, Musical Fidelity tri-Vista SACD.
I am now auditioning a Krell EVO402 for the last three weeks and it sounds remarkably good, very musical, without any apparent flaws or any "hey listen to this" hyper emphasis in any one area. It actually keeps sounding better each week.