IMHO, much of the brightness attributed to amps is actually due to the speakers. Speakers which are not time & phase aligned have the tweeter in early arrival, leading to an impression of detail, and, or brightness (YMMV). Almost all of the speakers measured by JA in The Stereophile exhibit this. That this is generally successful in the marketplace can be seen in the preceding remarks. Many persons try to attenuate this effect by playing with cables. (Just my $0.02)
Is it too bright or is it high resolution?
It has been said in the forums that one mans bright sounding amp is another mans high resolution amp. Some amps and preamp combinations can deliver a high resolution presentation and to others this may be considered too bright sounding. Is there a fine line that can distinguish between the two? Personally I like very revealing & the fine details delivered but the wife says it sounds a tad bit too bright.