Fuse upgrades? -- 6.3 amp 250v 5X20mm fast blow fuses

I doubt very much that a more expensive fuse will alleviate the fuse blowing trouble you are having! 
https://www.parts-express.com/littelfuse-63a-gma-type-5-x-20mm-fast-blow-fuse-5-pcs--071-834

Cooper-bussmann (USA), LittleFuse(USA), Schurter(Germany) ....and the the favorite of the Japanese audio business for over 50 years, SOC of Japan.

look for long lag fuses from any of those companies, and you'll be part way to the higher end audio grade fuses for a few bucks a pop.

Make sure you replace with the same type (fast low, normal blow, and lag types) as the manufacturer recommends.

That’s fine if you’re a Japanese businessman. But the favorites of real Japanese audiophiles are Isoclean, Furutech, HiFi Tuning, SR and Audio Magic. They eat the Bussman and Littelfuse for breakfast. 🍳 🥞 ☕️

Thanks for the insights, gents, much appreciated.  As you have noted, fuses blow for a reason, and I think in my case it has been due to poor connections with my interconnect cables and me fiddling with gear on rack.  I plead guilty!   I ordered some new bussman fuses as replacements and will ensure more firm connections with my cables to the gear.  Thanks again.