I have not done any mods but have tried several tubes.
My conclusion is the stock tubes are surprisingly well matched and perform very well. I expected to get huge gains when I went to smooth plate Telefunken's in mine and although it was an improvement, not what I expected.
This little phono is an incredible value and works amazingly well out of the box. Don't let me discourage you from experimenting, but I would suggest borrowing some premium tubes before dropping big bucks.
Also, the first tube is more important than second and third. You could get a snapshot of performance with a single premium 12AX7 that way.
My conclusion is the stock tubes are surprisingly well matched and perform very well. I expected to get huge gains when I went to smooth plate Telefunken's in mine and although it was an improvement, not what I expected.
This little phono is an incredible value and works amazingly well out of the box. Don't let me discourage you from experimenting, but I would suggest borrowing some premium tubes before dropping big bucks.
Also, the first tube is more important than second and third. You could get a snapshot of performance with a single premium 12AX7 that way.