I find that SS amps' lose bass at low volumes whereas tube amps don't. The Fletcher Muson curve will tell you that human hearing needs extra bass at low volume to get a linear response.Here's a perfect example of how ignorance spreads fast in free sites like Audiogon. It should be obvious that the Fletcher-Munson curves have nothing to do with the type of amplifying device, but rather with the sound pressure level.
Regards,