Ths sounds like an interesting turn on Nigel's dilemma. I agree with Sean, don't worry about the gain level on the preamp. I rarely turn my pre up to 40% of it's potential gain as I have large Monos. It's a good thing.
If what you are noticing is rolloff with high output from your SET amp, that's a different thing. SETs sound great, but do have inherent weaknesses, especially at higher output. It's the eternal SS vs Tube, SE vs push pull dilemma. Once someone can get the musical nature of these with the transient dynamics of a good push pull SS, everyone will want one. The too loud, if it is bloated and less coherent at high volumes rather than just too loud, it's a function of a SET amp at high levels. If it's just too loud, be happy and save some electricity.
On the other hand you could consider purchasing a preamp that "goes to eleven".
If what you are noticing is rolloff with high output from your SET amp, that's a different thing. SETs sound great, but do have inherent weaknesses, especially at higher output. It's the eternal SS vs Tube, SE vs push pull dilemma. Once someone can get the musical nature of these with the transient dynamics of a good push pull SS, everyone will want one. The too loud, if it is bloated and less coherent at high volumes rather than just too loud, it's a function of a SET amp at high levels. If it's just too loud, be happy and save some electricity.
On the other hand you could consider purchasing a preamp that "goes to eleven".