I also found the spark to sound warm but I can't stand it in high gain. Staging is way off to the point of being obnoxious. In low gain it sounds fine though. I would say it's all just placebo but I can say with confidence the treble is noticeably less fatiguing than what I'm used to. So much so I can listen to my edition 10 at mid/high volume without EQ on it and it's bearable, something that's impossible to do on my other amps.