First off I play a newer MKIV. I was playing live on Sunday and used 6L6's for the first set... during the break I put in EL34's in the otter sockets and I was amazed at the difference. The amp came alive! with better breakup and harmonic overtones that were amazing. I preferred the 6L6's playing at lower volumes as they seemed to be smoother and tracked better with better note definition but with a band and louder volume the EL34's seemed a lot better... Has anyone else had similar experiences where 6L6's are better at diferent volumes vs. EL34's?