The claim of a $50 fuse or a fuse costing thousands of dollars is unreasonable and arguments of ability to hear an improvement are not credible because those who make them can out-debate you even if you have a PhD in electrical engineering or a related subject. You won't get the whole truth about listening tests whether or exactly how they were conducted.What you might get is accused of rationalizing about your inability to afford the likes of power cords costing $20,000 and loudspeaker cables costing $27,000.
But suppose the fuse cost as much or more than the preamp. You might as well eliminate the fuse and let the circuit breaker in the house trip if there is a short circuit. If the preamp catches fire you will be there to get a fire extinguisher which costs far less than an "audiophile" fuse if the worst happens.
But suppose the fuse cost as much or more than the preamp. You might as well eliminate the fuse and let the circuit breaker in the house trip if there is a short circuit. If the preamp catches fire you will be there to get a fire extinguisher which costs far less than an "audiophile" fuse if the worst happens.