I concur with the Telefunken recommendations. I used them in the MC and line stages and left the stock tubes in the MM stage which I never used.
Once I put them in, I never thought about tube rolling again and they were perfectly reliable for the 2.5 years I owned the C2300.
Once I put them in, I never thought about tube rolling again and they were perfectly reliable for the 2.5 years I owned the C2300.