I've read that the rca's I have are pretty good in this pre. I'm gonna try some Genelex Golden Lion KT88's to see what they do for me. They are suggested units.
I've been running in the amp all day, so I got a good 8 hours on it. I'm happy to report that it has opened up substantially. The highs have smoothed out as well.
One thing for sure,is that interconnects make BIG differences in sound. So finding the right one might be long road. Especially since any good interconnect will cost as much as the amp. The trick will be to find one that's inexpensive and works.
I will say I can see what all the fuss is about with tubes. The presence of the music can be really life like.