|I just installed Isoclean fuses in my Naim CD5x and Nait5i. I sort of felt like I was going to the fringe by installing these but keep in mind they are right in the AC path so it made sense to me after installing a dedicated line and an "audiophile grade" AC receptacle. |
I tried Buss ceramic fuses beforehand and they were just slightly better than stock.
The Isocleans, however, definitely provided a noticeable improvement over stock or Buss ceramics. In a nutshell: smoother treble, a touch more overall resolution (especially in the mids and treble) and elimination of a bit of grain and veiling. Polarity does matter. I checked a few times to verify but arrow down for my equipment was more natural (less bright) than arrow up. You may prefer the other polarity, of course. Note that they didn't affect rhythm as many products do (especially a lot of isolation devices) nor did they add any brightness (at least in the polarity I prefer).
They're not cheap for what they are ($25 per fuse) but the improvement was definitely worth $50 total investment to me.