I had a 2.5 for a few years. I seem to remember the older versions of the 2.5 had different tubes than the current production model. Mine used 2x12AT7 and 2x12AU7, it didn't have the phono section.
I've got boxes of tubes I tried when I owned the 2.5. The brands that performed best for me were Mullard CV 12AT7 and Cifte 12AU7. Interconnects and power cord changes also made a big difference, maybe more than the tube rolling.
I've got boxes of tubes I tried when I owned the 2.5. The brands that performed best for me were Mullard CV 12AT7 and Cifte 12AU7. Interconnects and power cord changes also made a big difference, maybe more than the tube rolling.