The Bose 901's are not very conducive to modern audio gear.
If your receiver has pre-outputs, you can run the front right and left outputs to the Bose EQ then to an external amp. There is no way to use the amp in your receiver in this configuration.
If your receiver has a tape monitor loop, you can route the "tape out" to the EQ (instead of a recorder) and come back in via the "tape in" connections. This will work fine if you have a 2.0 system. If you have surround speakers, they will also get the EQ and you will not like the results!
