A couple of months ago, I received my BHSE (high end amp for electrostatic headphones), resulting in a big jump in transparency in my system. It has an over-kill power supply, so I did wonder whether a fuse change would make much difference. The BHSE actually has 2 mains fuses (one for live and one for neutral), so that meant double the usual cost . Which in the UK would be around £70-£80 for HFT Supremes or Furutechs, or £50 for Isocleans. Not a trivial amount.
But I came across a new (to me) fuse: AMR - A UK company famous(ish) for their heavy weight high end CDPs and amps, who decided to make their own fuses - because they like making their own stuff. Their marketing is refreshingly down to earth - not a hint of "quantum" or other mysterious properties. They don't have many testimonials on their site, but at least one contributor thinks the AMR fuse sounds better than all the others (well there's a surprise).
But what got my attention is that the 5x20mm fuses cost just £12 each, or around 1/3rd of the price of their top rivals. So I bough a couple, total price of £26 ($40) including postage.
So, what did the AMRs do to the sound? Much of what, IMO, any good power-related improvement does, which is to bring the performers/instruments/soundstage out from the mix, such that it feels a bit more like a live performance. Plus a reduction in mid/high frequency hash, such that the sound was simultaneously more detailed and yet less fatiguing. I love it when that happens.
These changes are objectively small (well they must be, mustn't they?), but gave a surprisingly big increase to my musical enjoyment, out of all proportion to their cost, or my expectations. And when I swapped the stock fuses back in, the performers/instruments/soundstage slightly retreated back into the mix, resulting in a flatter, blander sound.
I can't say how the AMRs compare to the other makes, and it's too much hassle to find out, but I'll guess that the AMRs are probably the best VFM, at least in the UK. Warning: the AMR's were fractionally bigger than the stock fuses, in both length and diameter. Why on earth? It took some coaxing to get the fuse tray pushed back into the BHSE.