What are your thoughts on Speaker cables or interconnects? Larger diameter cables are better so 2/0 welding wire should be great to use, but they sound like crud. So what is it then?
Large diameter cables with the same geometry lower R & marginally change L&C. When calculating impedance, L&C are squared terms while R is linear.
see
http://www.ielogical.com/Audio/CableSnakeOil.php
I'll bet your entire rig that if you let someone change fuses randomly without your knowledge, you will not detect any change. There are a lot of loonies in the audio field on both sides of the counter.
If the fuses or holders are ChiCom crap, replace them with Buss, Littelfuse, Osram or other reputable makes.
How often have foolzers left their gear connected for a year, decided to try a fuse, unplugged a bunch of connectors and
presto the fuse is 'magic'.
If everyone would replug all their cables every few months, they would also
transform their systems. If the system has fuses, reseat them as well. Ditto tubes.
I recently helped a fellow
repair a tube amp he'd picked up for a song by simply replugging all the tubes a few times. Connectors are crap. Gold or otherwise.
Many speakers have internal push on terminals. Some are less than stellar quality. Pull your speakers apart and solder all internal connections.
Fremer et al. make money reviewing stuff.