Did you buy the PrimaLuna from Upscale Audio? If so...even if not...I’d suggest calling Kevin Deal and telling him what you’re hearing. Ask him what tubes he would recommend to smooth out the rough edges. Better tubes than the new production East European or Chinese stock tubes will definitely improve the sound of your Evo 300.
I will call on Monday - I don't own the amp at this point, it was lent from a dealer to help make some comparisons with the Supernait 3 as I was having some issues with that amp and I needed some kind of benchmark to compare the sound.
I do like the Evo 3 though so I will reach out on Monday. I do have a pair of Mullard 12AU7/ECC82s sitting around here that I thought about swapping the Evo driver tubes over the weekend, but because I don't own the amp I did not want to risk any problems.
Just posting here in the event anyone had similar experience with the Evo 3 or experience tube rolling in the Evo 3 in general that could comment on that.
The stock sound does seem like it was voiced to be "exciting" out of the box... in fact kind of like a sublte Aphex Aural Exciter effect, or maybe it's just my ears.