I've had plenty of time during the mod process of this amplifier to think about how I would write this review. My objective is to be objective by recalling how the stock ZR-1600 sounded and at the same time give some comparisons to the amps I currently have.
Right out of the box the first thing I noticed was that the amplifier had not lost its character. It still possesed its unique sound albeit more dynamic and clean. Second, the fan noise was not noticable. Third, and most importantly to me was that the midrange and treble was coherent and more extended. In stock form I thought the midrange was good, however, the treble was not in sink with the midrange.
These are my early impressions. I will let the amp run continously until tommorrow when Steve from SAS Audio Labs drops by with his new 11A preamp and 10A preamp. We will do a more detailed review at that time.
Steve at Empirical Audio did a great job with this mod by addressing its weaknesses. With more break-in I will report back. As is an outstanding sounding amplifier.