Excellent review AK. You know I too see differences in the sound quality of my stuff all the time without any change in variables except time of day, weather etc. I know that at certain times the line voltage is steadier and cleaner, I know it can be steadier because we have measured it. In summer during hot humid days my system sounds lousy compared to other times. Evenings around dinner is bad, someone suggested that all the microwave dinners are being cooked. I don't know and I prefer not to stray too far into middle earth with this stuff but I can't help but think it may have an effect on reviews of equipment. So maybe that could contribute to the rather radical change of perception you found with this amp. Small story; A friend lived about a mile from the sub-station for Lilco. He swore for years there was a low level, sub-sonic freq. apparent in his downstairs bedroom. They responded with numerous explanations and tests but refused to admit that it did in fact occur. However all of the panel nails holding his wallboard in, have vibrated out upwards of an inch over the last 8 years. He claimed he could sense it while lying in bed at night and his lady freind claimed the same. It began to drive him nuts so he paid for an independent team to verify and sure enough they corroborated his story. Only after he threatened a lawsuit did the company apply some sort of filter, actually they never explained exactly what they did but the sound abated somewhat but he claimed it was still there. Finally sold the house for other reasons. He slept on a water bed, maybe the tides bothered him.