This looks like a very useful unit but it's a shame there is not a 2-channel version with RCA phono ins/outs. But then again... a reconditioned Quad pre/power combination would fit the bill nicely.http://www.tonelux.com/tilt.html
This seems to be exactly what we are talking about. It is studio gear and as I have no knowledge about that stuff I do not know if you can put it inbetween a pre and a power amp or how else to use it. There also is a microphone-pre from Tonelux with the tilt-function. Yet again I have no idea how to put that onto a regular home-listening environment.
There seems to be a software solution from Softube (made together with the Tonelux guys) as well. For that software they built a prototype which never got into production which seems to be exactly what we audio-fans would like to get: