I thought I’d create a thread on Unison Research’s Unico line of hybrid integrated amps. I’m specifically interested in whether people out there have tried rolling tubes and how much of a change have they heard. This is something I will do down the road after I’ve put some good mileage on my amp. I’m currently running a Unico Nuovo. Picked it up recently; a nicely discounted demo model. To say that I am enamored with this Italian beauty would be an understatement. I think it’s bar none the most impressive amp that I’ve had in my room thus far. The imaging is just stunning. Instruments and voices have body and texture, and are precisely placed within a wide soundstage. There is a real sense of being there - hearing a lot more spatial cues than I have heard before, coupled with that body and texture, really drives this feeling home. But most impressive to me is the depth. My speakers are diagonally placed in my room. I’ve heard depth before, but it was always sort of vague and extended back only so far. This is the first time I can clearly hear depth that goes beyond the corner wall of my room, and there is no vagueness as to where the sound is coming from. Wow! The amp is also very quick sounding, with plenty of authority (near 100 watts) and a nice amount of detail that isn’t fatiguing at all. And while the bass doesn’t stop on a dime or go incredibly deep, it is nicely controlled and punchy. Music has a real sense of flow to it and a lack of grain that allows me to just enjoy the tune. So the stock tubes (whatever they are) sound excellent. The thought that I might be able to improve on or tweak the sound by changing them is exciting. The amp takes 2 12AX7 tubes in the preamp stage. I have a bunch of options already as my phono preamp also uses this tube. At some point this winter I will probably experiment with some tube rolling. Looking forward to reading some impressions from folks who may have already tried this with their Unico.