Thanks all. Mike Lathat vigne's response is most interesting. The recent comparison that brought this to light for me was swapping my ARC Ref75se for a First Watt F7, running into Harbeth 40.2. (To be sure, I am talking about a decrease in the soundstage that WAS THERE in the source and system before just changing the amp). Technically the F7 (25-35W) is underpowered for the 86db sensitivity Harbeth's, but I was thinking no big deal - my ARC amp was rarely drawing more than 10-15W for the volumes I need. I am not a bass maniac and am satisfied so long as long as the bass is not muddy (the F7 seemed to have plenty of bass control). But perhaps the undergunning nature of the F7 affected SQ in other ways.
How Do Amps Affect Soundstage?
I'm not that technically strong on audio yet, so please refrain from mockery on this....
My DAC, premamp, and amp combo (all tube) throw a nice soundstage. If I substitute (at least some) solid state stereo amps, soundstage is constricted. If the amp is basically just increasing the signal that it is receiving from the preamp, I don't get how the size and shape of the presentation is altered materially from what the preamp is delivering. (I get that the signal could get distorted, etc.). How does the amp play such role? And do monoblocks enjoy any design advantage in maintaining the soundstage received? Thanks.