One of the big keys of the Maestro is a fairly extensive preamp. So while you could do a fairly good preamp within the Supra chasis, there are probably still some differences from a true maestro. That said, to me, the Singlepowers are transparent with respect to letting you hear your tubes. That assumes your amp is tuned that way. To me, adding stuff like a stepped attenuator, Paper in Oil caps, the Solen 3, etc... also move that away. That said I don't know that I would call any amps, including the ones that are purported to be neutral/transparent/whatever truly that at all. From what I've heard, they are all colored in some way shape or form. In some cases, they just happed to be colored in a direction that is favorable. But that's still colored.