SCI Six-Trak midi question

Hi

I recently got me one of these. Lovely synth!

I've managed to put it into multitimbral mode, with a separate midi channel/patch assigned to each voice. What I'm wondering is if it's possible at all to assign more than one voice to a midi channel. For example: three channels with mono patches, and the remaining three voices to one channel/patch (so I can play chords with that sound)?

I know it's possible with the internal sequencer, just not sure how to achieve this via midi using an external sequencer...

Thanks

Rvk