Stickman, I doubt that the 28BSST2 would be a suitable match for your Hovland preamp. As with a number of other Bryston amps, its input impedance is lowish, in this case either 15K or 16.5K for its unbalanced input, depending on what document is looked at. From JA's measurements of your preamp:
-- Al
Despite the claim that the HP-100 uses a cathode follower output stage, its source impedance was high at 2.4k ohms, rising to 4.3k ohms at 20Hz. The partnering power amplifier would best have an input impedance of at least 47k ohms if the bass is not to sound lean.Regards,
-- Al