Hi-Fi Tunig Fuses & Parasound A21

I blew my hifi-tuning gold rail fuses in my Revision A+ of my McCormack DNA-1. MY bad.  After calling Steve McCormack he discussed his preference for the silver star over the classic gold and supreme fuses.  He was disappointed that Hifi-ftuning stopped producing the silver star in favor of the supreme fuses.  He tried the supremes on two separate occasions and just did not get the openness and clarity of the silver stars.

After speaking with Steve, I googled silver star fuses and fortunately, Parts Connexion had them in stock at 60% off!!  Instant order.  In the interim, I procured Bussman ceramic body "microwave" fuses so I could listen till the silver stars arrived.  The Bussman weren't bad in the sense that I had music but the subtleties were MIA.  The sound was "matter of fact".

The fully run-in Silver stars have really opened up the soundspace.  There is "space" between and around instruments allowing each contributor to shine on each cut.  Great stuff.  Steve knows his stuff.

How does the fuse add "space" around instruments? Does it make the electrons go faster? Slower? Adds molecular grease of some sort? Electron happiness? Electron purposefulness? Do the caps and diodes and transformers simple feel better working with the juice once it's been through a half inch of "special" wire? Maybe I should call Steve…he must know.

@toolbox149
I have replaced both the main and the 4 rail stock fuses of my Parasound A21 amplifier with Hifi tuning fuses. I replaced these fuses in sequence. First replaced only the main fuse by Hifi Tuning Silverstar fuse and it immediately improved the sound in all areas. What I liked the most is the blacker background and the improved clarity. Not sure how it dropped the noise floor but it did.
Then I replaced all 4 rail fuses with Hifi Tuning Gold fuses (couldn't get the Silverstar in 8A rating) with the arrow pointing to the flow of the current i.e pointing from the transformer to the capacitor. The result wasn't so impressive. While it further increased the clarity but the instruments started sounding very hazy and smeared. The overall sound was also veiled. It has been 20 odd hours since I replaced the internal fuses and they might still be going through the break-in interval. I tried flipping the fuses such that they point to the transformer to see if that resolves the haziness issue but it didn't.
Did you have similar experience when you replaced the rail fuses inside your amplifier? Did you find any break-in period with these fuses? Any feedback/help in this regard would be greatly appreciated.Thanks.

Like most anything that impacts the electrical circuit of a piece of kit, break-in is necessary. Obviously this requires patience, a virtue few of us in this hobby possess in abundance. I don’t have an electrical engineering degree that might help inform me as to why things in this quizzical hobby happen as they do but they do occur. There is plenty of anecdotal evidence of such all over this site. Perhaps the mystery is part of the appeal.

As far as Steve McCormack goes, I know what my stock amp sounded like and what it sounds like post SmC Audio mods. Nuff for me!

It took about 4 days for my HiFi Silverstar fuses to break in. I kept the amp on 24/7 and would turn up the volume now and then to get a handle on the sound. I still don't know or understand how anyone can hear an immediate improvement, but that's been my experience. By the way, I replaced all the fuses at the same time, if that helps to clarify anything.

All the best,
Nonoise