Would like to mod Krell Home theater Standard.

[gto127]

Hello Everyone. I would like some ideas & possible simple schematics to mod a original Krell home theater standard to have 5.1 analog inputs. I would like to mod using relays for each channel & use no coupling caps in the signal path. As many of you know this preamp section has no true analog inputs but converts all analog to digital then back so I will need to first find the beginning stages of the analog ouptput section & mod from that point. I also plan to simulataneously run digital input from same source to keep relays open in the output section & keep mod to something very simple. There are no schematics for this unit so I will be working with a scope & voltmeter only. Any ideas would be appreciated.