The Senns are pretty efficient so you probably don't really need the extra power of Amp Two; however, it might later be useful if you bought some less efficient cans like the AKG 701s.
With cans you hear every bit of noise, so if I had to make a choice I'd go with the high signal to noise ration of Two. That said, if you can listen with your own cans, do that a buy based on the best subjective sound.
Like loudspeakers, but maybe more so, cans have incredibly distorted frequency response curves and actual perceived response will vary widely from user to user, thanks to different ears shapes, etc. So, worrying about the last iota of amp frequency response is a futile diversion. With cans and there amps you really need to listen.
Break-in/burn-in is very critical with cans. The close proximity of the drivers to your ears will really highlight any hardness that new equipment tends to show.
Dave
With cans you hear every bit of noise, so if I had to make a choice I'd go with the high signal to noise ration of Two. That said, if you can listen with your own cans, do that a buy based on the best subjective sound.
Like loudspeakers, but maybe more so, cans have incredibly distorted frequency response curves and actual perceived response will vary widely from user to user, thanks to different ears shapes, etc. So, worrying about the last iota of amp frequency response is a futile diversion. With cans and there amps you really need to listen.
Break-in/burn-in is very critical with cans. The close proximity of the drivers to your ears will really highlight any hardness that new equipment tends to show.
Dave