So the PH16 phono stage basically uses 6922's, at least that seems like the most common number that comes up.
7308's, and 6DJ8's should work OK as well I take it.
I saw in the PH16 instructions I think, that 6CG7's will also work, well but maybe only in the buffer stage. Apparently these are basically 6SN7's in a smaller package.
Is there a reason why these might be recommended for the buffer but not the input stage?