Currently available from Bass Emporium:
Demeter HBP1 Vacuum Tube-FET Hybrid Bass Preamplifier
Demeter VTBP-201S Vacuum Bass Preamplifier
Demeter VTDB-2B Vacuum Tube Direct Box

After 20 years of production the Demeter Amplification Tube Bass Preamplifier (VTBP-201) is still the only musical instrument preamplifier to incorporate a truly modern tube design technology with circuit features found on only the most expensive and esoteric, tube hi-fi equipment.