Are the channel strips in the $200-$300 used range any good as a bass preamp? I see quite a few tube preamp models coming up for sale. For that matter, would a tube mic preamp work well? I've read that some guys here use channel strips and power amps for their live setup, but are the less expensive ones as good as a designed bass preamp? (and I guess the same question about mic tube pre's, they come up for much less). Are either suitable for substitution as a DI box?