Thanks Guitarhacker!

That's just about what I ended up doing. I did some 'net surfing on the specs for the 2 Shure mics I had. Then I just plugged the PBass into the "High" input, and tried each of the mics into the "Low" input until I found something what worked.

Thanks to all for your input and ideas.
I used the setup at a gig yesterday and it was fine. Another one today, quite a bit bigger venue. I think that little Roland amp will be adequate.

LLOYD S