[quote name='wateroftyne' timestamp='1456303666' post='2987474']
Has anyone on here ever had a valve pre go bad?
I suspect the role of the preamp valve in hybrid deaths is minimal...
[/quote]
No, and that includes gigging all-valve guitar amps for the last 20 years.
EDIT 1: Far more likely for the Class D power stage to die!
EDIT 2: Just checked out the Streamliner 900 schematic, and both the effect return and the aux input come in [i]after[/i] all the valves, but [i]before[/i] the master volume. Thus if one of your valves died on a gig, you could plug your bass into one of these sockets and at least get some kind of a signal. The input impedance is about 100k, so it would work best with an active bass, or via a buffered pedal (or better still a preamp pedal). I haven't tried this, so no idea how loud it would be.