Is it possible to route the "sub in" feed to tape or is it strictly designed to go to mix down? All I can gather out of my manual is that it the signal is routed to the master fader (no duh!).
The Sub-In signal goes directly to the Master Fader, which is the Stereo L/R Buss, which, if you choose, may be recorded with Buss L/R mode to tape tracks.
The Sub-In signal goes directly to the Master Fader, which is the Stereo L/R Buss, which, if you choose, may be recorded with Buss L/R mode to tape tracks.