Bojack,
As you can see from the responses you are getting, opinions will vary greatly. That's to be expected since all we can do provide your with out best guesses. The only component I've owned that you have are is amp. I don't think your amp is the problem, although the high frequencies can tend to a little on the bright side. I agree with you on looking at your preamp first. Theres no guarantees, of course, but I believe its the most sensible thing to look at first. I think its a mistake to only consider a tube preamp, though. My primary focus would be on getting a good preamp; tube or solid state. Just because a preamp is solid state, doesn't mean it won't work for you.
As you can see from the responses you are getting, opinions will vary greatly. That's to be expected since all we can do provide your with out best guesses. The only component I've owned that you have are is amp. I don't think your amp is the problem, although the high frequencies can tend to a little on the bright side. I agree with you on looking at your preamp first. Theres no guarantees, of course, but I believe its the most sensible thing to look at first. I think its a mistake to only consider a tube preamp, though. My primary focus would be on getting a good preamp; tube or solid state. Just because a preamp is solid state, doesn't mean it won't work for you.