I've looked/ebayed a lot around to find a good audio matrix switcher with a rack format... and.. finally, some months ago, i was so lucky to find -half destroyed- this little piece of audio-video equipment: a Kramer Vs-5x4.
The VS-5x4 is an audio-video switcher with audio RCA and video BNC connectors on the rear and the possibility to be remotely controlled via an rs232.
After a little work (and a BIG patience) i modded his power supply for 220v (I think was imported in EU with an US power supply) changed the power button with one working (and a power lamp) and rebuilded some rear connectors.. but the little Kramer, inside, was almost perfect.
So.. a fantastic solution for routing audio between 5 inputs (gm6790,775dsp,ar5000,ar5000,icr20) and 4 outputs (now only 2 used for the 2 pcs line in).
But now.. a terrible idea is growing in my mind : the video part is still unused :)))))
