I replaced the normal fuses in my EA Benchmark DAC1 with a pair of Isoclean fuses.. It is more analog like now..  Smoother high and decay more naturally.   Speed is fast with detail without feeling bright or harsh.  The funny thing was, I didn't know my DAC1 has 2 fuses (one per each channel).   I only bought one home and plan to give it a try.  Then I realized it takes 2 fuses..  So I ended up plug it in for my left channel anyway..  Wow I noticed my left channel has faster speed and more decay longer with natural tone compared to my right channel..  I was convinced and right away, called my dealer to ship the second one...   Isoclean is gold plated fuse with gold plated contact on each end..  I never try the the HIFI tuning fuse though..  I will try them on my new Spectron Musician 3SE amp pretty once I have break in process complete. !