@atmasphere I suspect that based on what I read concerning the EAR 864 preamp, that it has an unregulated power supply. The result of replacing a Bussman glass fuse with an SR Blue fuse was fundamental and sensational. I was ready to dump this 17 year old back-up pre-amp which sounded like it had no depth, forward sounding and weird brightness with many but not all recordings turned out to be totally the fault of the cheap fuse. I had it plugged into high end power cable, Stillpoint Ultra SS footers, Mullard 4004 & RCA cleartop 12AU7. The SR Blue fuse transformed it into a rival for the EAR 912 (I haven't done the shoot out yet). The phono is a perfect match for the Dynavector 20X2 L and the line stage made digital recordings sound analog. This is going through an EAR 890 amp with an SR purple fuse (even with the 890's glass fuse, it sounded very analog-like).