New F-50 owner changed PI Driver tube

I am really lovin my first Boogie, well Mesa.
I recently scored one of the early f-50 Combos for 6 bills,
it has the smaller 1-12 cab not the wide body.
This amp sounded good as is with a set of gtubes put in by the previous owner, but you are always suppose to change your phase inverter tube which drives the 6l6 outputs
and since I am used to Fenders and I play blues and rock I decided to try a lower gain nos 12at7 in place of the 12ax7 driver tube as I have read some have done. I also tried a new 12ax7 and that helped driver circuit too. But I liked the 12at7

Made a difference I really liked, it seemed to smooth out all the gain and made the clean channel even better it still smokes on lead and contour settings if I set the gain up.
Worked for me and now I can't stop playin through this amp!

Next thing I will try is the effects loop as a final volume control, thanks for all the info here.

New(ish) F-50 owner here, too. This seems to be a great place for picking up info on fine-tuning the amp (settings, tubes, etc). Awesome amp to begin with, imo, but I'm finding the discussions about tube differences very enlightening (and tempting, lol). Thanks all.

so what tubes are you runing in the pre amp
v1
v2
v3
v4
and what 6l6s do you have

i have a 2003 wide body f50 with a celestion gold

v1 is a gt 12ax7m
v2 is a gt 12 ax7m
v3 is a sovek 12ax7lp3
v4 is a sovek 12ax7lp3
and i have mesa str 425 power tubes
this is how it came when i got it and am looking to blues it up thats why i swapped the mc90 for the gold