I've run the KT120 and now the KT150 tubes in my PrimaLuna. As good as the 150's are, I've noticed that I can't really listen to music in Ultralinear mode since I added them unless the volume is kept pretty low. I'm thinking about trying out the EL34's since my Shindo amp is still a few months out. I'm never selling the PrimaLuna anyway, so the EL34's will find some regular use even if the PrimaLuna gets relegated to the bedroom. What are the best NOS EL34's to try?