Is there a solid fuse-like item that I can use in place of a fuse, to bypass it?

Big fan of this idea.  

If you are able to spend thousands of dollars of disposable income on the smallest nuance of sound improvement, and you are convinced that the fuse reduces sound quality, then you can afford to buy a new component if it fails when the fuse could have protected it.  

I have a lathe and can turn you a piece of copper the size of your fuse.  It would be better to get it silver plated.  

Alternatively it could be coated in anti-oxidation grease.

Send me a message if I can help.

Jerry

If you think the fuse has that significant and adverse effect on the sound, such that it is worth risking the component and a fire, then don't stop short by just replacing the fuse--bypass the fuse holder by directly wiring the power cord to the internal wiring of the amp.  This would mean removing any IEC power cord plug as well.  Any kind of junction is, at least theoretically, a source of degraded transfer of power, so these should be removed along with the fuse and fuse holder.

Personally, I would NEVER remove something as fundamental to protecting gear and preventing fires as the fuse.  I consider this the first line of defense, and would only consider adding more, not less protection, such as surge protection, soft start, etc.

Then you may next consider, as I've read a couple here have supposedly done, wire your amps straight into the wall ... 🙄 (don't)

It appears the amplifier i’m using has two 7A fuses accessible from the outside, and 5 or 6 lower amperage fuses on a PCB in the amps power supply.

In a potential sound-enhancing compromise, I can replace 5-6 lower amperage fuses with solid copper cylinder shaped objects, and leave the two 7A as is...for safety...

...but actually perhaps swapping the 7A fuses also, for some aliexpress "Fever-grade" fuses that make extravagant promises.