If upgraded fuses I purchased were the SR Black. Upgraded to the SR Blue when they made them user friendly (immediately better without 72 hour break-in of the Blacks). My audio engineer friend and manufacturer of cables who has the same equipment as me, thought one better (if it can be made the same but cheaper is his motto) installed 5 amp circuit breakers instead of buying 8 amp SR blue fuses for our amps. About the same result but his was infinitely less expensive. Until I demonstrated a littlefuse versus the SR Blue, he didn't believe it.
So, a huge Yes on fuses. Plus, they are directional from the start, no waiting needed to hear the difference.
So, a huge Yes on fuses. Plus, they are directional from the start, no waiting needed to hear the difference.