We're going to keep disagreeing on this but hey that's life....
Cables of whatever variety obviously all sound the same within the predictions of physics ie a the capacitance of a long coax cable may well roll off top end and resistance of speaker cable will make a difference. These are simple 1st order effects and cables are completely "blameless" at audio frequencies. Fuses in mains circuits can NEVER have any effect, nor can mains cables themselves. "Grounding boxes" and such like.... well anyone stupid enough to think they even may help deserves to be ripped off really! Rather a pre Darwin Award purchase...
(Fuses DO have an effect when used as speaker/amplifier protection, ie when the output of a power amp has a fuse in line with it either in the power amp or in the speaker, and it is a negative effect. Strangely this is rarely mentioned)
Pre amps, phono stages (especially), power amps, DACs, ADC's, CD players, speakers, arms, cartridges, tuners etc etc can all sound different, sometimes very different, and once those differences which can be attributed to measurable issues have been eliminated, often obvious differences remain, which it seems we do not yet have measurements available to us to account for.
Have you ever probed around with a scope and followed the signal from input to output in a typical high feedback, low distortion amplifier? Often you will find GROSS distortion (maybe 30% or more!) and some bizarre looking waveforms generated by the feedback doing its stuff to generate "anti-distortion" (error signal) to counteract non linearity.... and this is just with a steady 1KHz sine wave!
When you consider the constantly changing nature of music with all those different frequencies and transients going on it does not surprise me at all that amplifiers can sound different.