I bought a proteus 2000 sound module which has 3 pairs of stereo outs.One I use for drums one for bass. I play the sequence on a laptop and set channel 10 (drums) on the keyboard not to accept midi. That passes it through to the module which I can then route any way I want.
Thanks for all the suggestions. I suppose this means that anytime you add an off board synth to the PSR 3000 sequencer the track will always be doubled by a voice from the 3000 whether you like it or not?
BTW I just picked up an RX 21 drum machine for 20.00 on ebay. It should cheaply solve my dilemma