Matching a preamp to a power amp is part of system synergy, but it should not be as much of an issue as getting the right amp for your speakers. Aspects of your amp's design like damping factor and power bandwidth are far more important when choosing speakers than your preamp's characteristics.
When a system does not prove satisfying at low levels, the problem is much more likely to be one of resolution than of volume. We turn up the volume to hear more detail. It works, but only a little. Previously inaudible sounds can be heard a bit more easily but now we have to filter out the roar of the loud stuff. The only way to really improve things is to upgrade to components with higher resolution, starting at the source.
Harsh highs are sometimes a room issue ( or issues ). At any rate, it is often cheaper to start there. I would guess, though, that you will fix the highs a good deal when you apply the upgrade remedy to the low-volume problem.
When a system does not prove satisfying at low levels, the problem is much more likely to be one of resolution than of volume. We turn up the volume to hear more detail. It works, but only a little. Previously inaudible sounds can be heard a bit more easily but now we have to filter out the roar of the loud stuff. The only way to really improve things is to upgrade to components with higher resolution, starting at the source.
Harsh highs are sometimes a room issue ( or issues ). At any rate, it is often cheaper to start there. I would guess, though, that you will fix the highs a good deal when you apply the upgrade remedy to the low-volume problem.