Usually bass problems have little to do with Preamps in general, or it is unlikely that a Preamp would cause boomy bass. Typically boomy bass is the result of speaker and room interaction.
Nevertheless, in response to your question about SS preamps, you could take a look at those from Pass Labs. Even the older L or P were excellent. Although personally I do like the ModWright SWL9.0SE, which although is tubed, sounds very neutral and more like a good SS preamp, than a tubed one.
Nevertheless, in response to your question about SS preamps, you could take a look at those from Pass Labs. Even the older L or P were excellent. Although personally I do like the ModWright SWL9.0SE, which although is tubed, sounds very neutral and more like a good SS preamp, than a tubed one.