Like most other Bose systems, it seems to route the signal through the bass module before it gets sent to the other speakers. This is not a standard hookup that any other receiver I know of can take advantage of. Not to mention, Bose often uses proprietary speaker wire. I think your choices will be to see if Bose will sell you another receiver for that particular system, or just chuck the whole thing and go with a setup that uses standardized connections and wires so you can upgrade components our at will.
This is one of the reasons I don't recommend Bose systems to people. There's no good reason to have these proprietary connections and wires... aside from keeping you locked into the Bose universe that is.
can you use any other amplifier with the bose lifestyle 38 instead of their bose 2A or 3A with its wireless set up