[lostpick]

Originally Posted by Billm

It's not a resistance problem and it's certainly not the solder!

As I recall, Canare cable has a fairly high capacitance per foot, around 50pF. (I'll look this up later if I get a chance.) So even a 10 foot cable is adding 500pF to ground. It acts as a low-pass filter. On paper, it's a first-order low-pass filter, and it rolls off highs at 6dB per octave. The actual amount may be greater after it's done interacting with your guitar and amp.

GS6 cable is built for low microphonics, not low capacitance. It resists handling noise, slapping against the stage, etc. I use Mogami cable for the same reason, but it has almost half the capacitance of the Canare.

The amount of roll-off you get from a cable is dependent on both your guitar and your amp--they form a resonant circuit. That's why some people report great results and you try the same cable and hate it.

BTW, the brightest cable in my collection is some cheap Chinese 20 foot POS that a used-guitar dealer gave me when I bought a bass for my son. The plugs were crap; I replaced them with Neutriks. It tends to break at the strain reliefs, so it keeps getting shorter in 6-inch increments. But it sounds great. Go figure.

This is the most likely explanation...
if the cable tests OK with a meter...