Loudness and warmth, it's all here
Came from a matched and balanced set of JJ Gold tubes, one of which went bad after 18 months. Popped these babies in my Budgie preamp and wow, the gain is amazing. Running a high output moving coil Denon DL110 which usually requires adding 20% to the volume knob. With these tubes I literally turn it down a little. They're still breaking in but so far the change is huge and noticeable, to the point where an untrained ear can clearly hear the difference. So far, so great.