I mean, we know for a fact that audiophiles are delusional, but I remember computers of the time had terribly noisy audio output affected by all kinds of EMI, from fans to hard drives to CPU utilization. The noise floor was a mess on most devices. I even remember listening to the interference from my arriving SMS messages, zap-zap-zap. Desktops also tended to make about the same amount of fan noise as a space heater. Pretty much the only common device of the era with a good SNR and no screaming fans was the iPod/iPhone.
Pretty much any Apple device was surprisingly better than the median PC until the late 2000s or so but that wasn’t because Apple was great so much as even the big PC vendors couldn’t pass up the chance to cut corners. So many vendors would sell you a $3-5k computer and then save $0.50 on the DAC or use a noisy power supply. I used to work with some researchers who collected lab data by connecting sensors to line in audio and they did some tests & found that the Mac audio input was roughly the same as the external boards they had been paying a scientific supplier a few grand for but the comparable priced Dell & HP workstations had a shocking amount of electronic noise. Granted, I had a $50 Belkin USB audio adapter which was even better because it did higher bit rate and depth than was common at the time.
(There’s a famous exception on ambient noise: the PowerMac G5 was like having a hair dryer running in your office.)
Yeah until I got balanced jack-to-XLRs for the Focusrite to the monitors, the cables were insanely affected by EMI from my GPU. Whenever it did more than move windows around (i.e. starting a game, playing a video) it noised out like crazy.
