A tade more briteness - Jolida 302b. Tubes?

Can I substitute the 12AT7 with EI 12AU7 in the Jolida 302b?

I would change the input tubes with mullards or others. They make a big difference to the stock tubes.

Or look into an ASL aq1001DT - it is a tube integrated that sounds like a tube and SS - which will brighten things up. At least it has solid highs for me.

I have settled on the the following combination after much experimentation with current issue tubes.

Svetlana EL34 (also tried Mullard, JJ Tesla, Mesa Boogie, Chinese stock)

Tung-Sol 12AX7 (also tried Ei, JJ Tesla, EH, Sovtek)

Mullard 12AT7 (also tried JJ Tesla and EH)

Extension, detail and image are now the best I've yet heard on the 302B.

After tube rolling with Mullard, JJ Tesla, Sovtek and the EH el34's. I found that the Electro Harmonix Big bottle 6CA7's were over all killer in my Jolida 302B amp. Excellent highs and awsome bass response very clean.
The preamp tubes I am using the EH gold pins 12AX7/12AT7.