What's your budget? You may consider getting a second 270 somewhere and monoblocking them, very easy to do, or, if you can afford it, the new Berning monoblocks are available. I had multiple 270's, and the new monoblocks are just in a different league. I still have my MX's too, I should hook up the Bernings to them to see what they'll do.
One other thing--how old are the tubes in your Audio Aero? I just had mine replaced after 3 years (I leave it on standby most of the time), and wow, what a difference. Of course, I also added an Elrod cord to the AA, but regardless of what caused it, there was an immediate increase in bass.
One other thing--how old are the tubes in your Audio Aero? I just had mine replaced after 3 years (I leave it on standby most of the time), and wow, what a difference. Of course, I also added an Elrod cord to the AA, but regardless of what caused it, there was an immediate increase in bass.