PrimaLuna Dialogue Premium preamp owners!

Please help me. Looking for new tubes. I read that it is difficult to beat the stock tubes, but I am willing to try. I am currently running a Pass XA-30.8 amplifier, Harbeth Super HL5+ speakers and an Esoteric K-07 as a source. I listen to rock, jazz, classical. Love female vocalists accompanied by the piano as well. I want to avoid anything that will accentuate high frequencies or anything that may cause harshness in the upper registers. All that being said, I was considering Amperex Medical 12AU7, Brimar CV4003, Cifte 12AU7 or Mullard cv4003. Or something else? Thank you in advance.