I'm using a quad of the KR labs 242 output tubes in my Lampizator Pacific DAC. I have a set of the PX4 and the 300B-98B mesh plates which sound very good in their fashion, but the 242 tubes are more consistent bottom to top. Their top end is especially natural. The 242 tubes do have higher gain which can be problematic for some active preamps. I use the Tortuga LDRxB passive controller which loves the 242's.