I have found the Shuguang Black Treasure CV181s and KT88s provide very good sonics and reliability in my Modwright LS100 preamp, and Ayon Spirit 2 integrated, respectively.
I use either NOS Phillips or Mullard 5AR4s in my Modwright LS100; Elyse DAC, and LineMagnetic 518ia integrated
I use either NOS Phillips or Mullard 5AR4s in my Modwright LS100; Elyse DAC, and LineMagnetic 518ia integrated