Pass Labs XA30.5 Fuse Issue/Question

Hi all!

I recently acquired a Pass Labs XA30.5 from our friends at The Music Room and paired it with my Harbeth P3ESR speakers. It worked perfectly for about a week, delivering great sound with the needle hovering around 12 noon, even at high (to me) SPL. However, after a week, the fuse blew.

To get back to listening, I checked the back panel, purchased a set of 4A slow blow fuses (as labeled), and installed a fresh one. That’s when things started getting strange.

The unit powered on as usual, but as soon as I increased the volume to a moderate level, the needle swung wildly and pinned itself to the far right before the fuse blew again. I assumed it was just a bad fuse, so I replaced it with another. Same result. I tested the amp with a different set of speakers and a different source/preamp, but the same issue occurred every time.

I’m completely puzzled. It seems unlikely that all the replacement fuses are bad—could they be mislabeled? Does this pattern suggest any other potential issues?

I’ll reach out to Pass Labs if I can’t figure this out, but I wanted to check if anyone here has experienced something similar with their Pass equipment.

Thanks!