This is a somewhat older thread. But I purchased 4 of the Acme cfc coated fuses. I have them installed in my MF m6prx power amp. I have a SR orange fuse installed in my MF m6sdac. The SR orange fuse has hundreds of hours on it. The Acme cfc fuses have only 55 hours on them. So far they are sounding smooth and clean. Now the acme fuses might be letting the SR orange fuse work better also. But at $640 for 4 of the SR orange fuses for the amp the Acme cfc fuses at $18 each will do my amp good.