As you already gleaned, the DSP only accepts left and right inputs. It was designed for car stereo applications and I doubt it has multi-channel capability. There are some capabilities in the chip that aren't being used by Empeg, but surround-sound processing isn't one of them.

If you want to look it up, you can grab its spec sheet in PDF format off the web. Do a search on "SAA7705H".

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Tony Fabris