I replaced the stock fuse in my Exact Power ep15a with an Acme CFC fuse and really enjoyed the results; noticeably more lively overall.
I'd been using an SR Orange fuse in my integrated amp, and decided to try the Acme. My "expectation bias" favored the Acme but, excepting for a more extended top end, the Orange was better. Ultimately, I put an SR Purple in the integrated and that's the best yet; excellent highs and more harmonically complete mids.
There's now an SR Purple on the way to replace the Acme in the Exact Power ep15a. If it doesn't outperform the Acme, I can return it.