Someone tried to troll:

Can anyone give an opinion of the phono stage of a Dyna PAS-3X preamp ?

Yep, it's of unexpected good quality with a good MM cartridge.
It could get a little noisy though.
For optimal sound, one could rebuild to a CC circuit, passive RIAA,
and then again a CC circuit. Stabilize the HT supply and swap the
selenium heater rectifier for a SS bridge. The 12X4 rectifier will
probably live forever.
Gain will be a tad low, but excellent stereo imaging and detailing
will be your rewardings.

Excuse me for ignoring the rest of your post.

--
Sander deWaal
"SOA of a KT88? Sufficient."