I just bought a K7 player and I listened my old k7 made in the 90's and perhaps I will publish some of my old tapes but finally I plugged my old external fx, very low cost, like my Alex (Lexicon) and my Quadraverd (Alesis) to the second output of my SB to use them in this track.
I used the Polymod like a sophisticate SF2 player for the Bass and acoustic drum.

I just use the built-in Fx with the drum (delays) and also for the background Fx.
I made a cable with mini stereo jack to 6 jacks, 2 for each reverb and 2 to link the mixing console Fx send (old rack 1U Roland for keyboard).