I have retubed the line stage side of my 5.5 and I have found that the Mullard CV4004 tubes were my favorite so far. They have a very nice midrange and extended highs that sparkle but are not too bright. The bottom end was tighter thant the stock 12ax7s.
I also tried some Telefunken ECC83s for a little while. They were very nice. The mid range was very lush and pretty. I thought the highs were a little rolled off and the low end didn't have the same punch as the Mullards. I liked the Teles but I thought they were a little too polite.
I have and older TL 5.5 and it uses 6350 tubes in the line stage instead of the 12at7s. I switched these out as well with some tubes labled IBM but noticed no difference from the stock tubes.
My phono stage is very noisey as well but I don't have a turntable hooked up to it. I am interested to see what you come up with to fix it, as I am thinking about getting into turntables.
Hope this helps a little
Jim
I also tried some Telefunken ECC83s for a little while. They were very nice. The mid range was very lush and pretty. I thought the highs were a little rolled off and the low end didn't have the same punch as the Mullards. I liked the Teles but I thought they were a little too polite.
I have and older TL 5.5 and it uses 6350 tubes in the line stage instead of the 12at7s. I switched these out as well with some tubes labled IBM but noticed no difference from the stock tubes.
My phono stage is very noisey as well but I don't have a turntable hooked up to it. I am interested to see what you come up with to fix it, as I am thinking about getting into turntables.
Hope this helps a little
Jim