When you say you preamp phonostage uses ecc81/12at7, and ecc83/12ax7, and ecc88/6dj8/6922, is this all the tubes in your preamp, or is this the tubes in the phonostage, with other tubes else where?
Your phono might be only one type of these tubes, and the line stage , in you pre, another type. To improve the phono, you would only really have to change the phono tubes, to have the greatest effect.
As far as sonics, only listening to the actual tubes in your preamp circuit will tell, everything else will be a general rule of thumb, which may, or may not apply. Most vintage tubes, tend to sound better, than most modern tubes, generally
I am a tube seller with over 40 years of experience, with buying and selling tubes. I have built a bunch of tube gear, and the same tube sounds very different, in different circuits.
If you can afford it, pricey NOS tubes, should always be the choice, as their value seems to go up. So if you did not like the choice, or found a set you like better, they can be resold. If on a budget, then vintage RCA, GE, and the like, can make a worthwhile improvement inexpensively.
Your phono might be only one type of these tubes, and the line stage , in you pre, another type. To improve the phono, you would only really have to change the phono tubes, to have the greatest effect.
As far as sonics, only listening to the actual tubes in your preamp circuit will tell, everything else will be a general rule of thumb, which may, or may not apply. Most vintage tubes, tend to sound better, than most modern tubes, generally
I am a tube seller with over 40 years of experience, with buying and selling tubes. I have built a bunch of tube gear, and the same tube sounds very different, in different circuits.
If you can afford it, pricey NOS tubes, should always be the choice, as their value seems to go up. So if you did not like the choice, or found a set you like better, they can be resold. If on a budget, then vintage RCA, GE, and the like, can make a worthwhile improvement inexpensively.