Having owned multiple models of ARC solid state and Adcom amps through the years, I am certain the ARC would sound superior to the Adcom. I would advise calling ARC, however, and verifying if the D240 is still serviceable (if it ever broke down). I like ARC gear, but some of the older solid state stuff has components they have obsoleted and cannot be serviced. I would advise making sure the D240 isn't one of them.
Audio Research D240 mkll vs Adcom GFA-555
Hey Folks, I currently have a modified Adcom GFA-555 but have the opportunity to purchase an Audio Research D240mkll. Will there be a significant increase in sound quality? Speakers are Sonus faber Chameleon B's and source is Tidal through a Project Pre Box S2 Digital (as preamp).