I learned my lesson about shielded cables today. I had been using cheap RCA leads (with "gold" connectors, but unshielded) to run a signal from my guitar preamp to my soundcard, for a few years.
Last week I decided to put a compressor pedal before the guitar preamp, and it began picking up a LOT of noise. This trigger a chain of events that led me to replace all the cables in the chain with shorter (1 metre/3 feet), properly shielded cables. I was immediately blown away by the improvement in the sound. What I had previously been trying to correct with EQ was suddenly no longer an issue! I realised I'd been losing a lot of high frequencies from running long cables, and introducing noise with poor/no shielding.
Replacing the three leads in this chain cost about $40. But there are plenty of people out there who pay way too much because they think they have to, and also plenty of people willing to take advantage of them
