Pre-amps with seperate power supplies .....

Seems to me Fulton was making power cables. Its been a long time but I seem to recall Sumiko had something too.

Maybe MAS in the later 1980s.

Atmasphere, The more I think about this the more it doesn't sound right. Atma-Sphere may have been installing IEC sockets in 1985, but I doubt it was for aftermarket power cords. Even 10 years later aftermarket power cord were not very popular.

I bought my Cardas power cords at CES in 1990, about 5 years after we switched to IEC connections. By that time Cardas was already doing quite well for himself :)

I do remember thinking that I didn't want to deal with how people would cut up the wiring in our amps which I was hoping to eliminate by using IECs.

In 1990 we built the first MA-2s. That amp had (and still has) two IECs *per chassis*, and also different (larger) fuseholders, as we wanted to reduce the effects of the AC cable on the sound of the amp, and having two AC circuits was an easy way to do it.

That was also done to reduce the effect of the internal AC wiring; the special fuses were used because they sounded better- a good 18 years or so before upscale/aftermarket fuses became popular in the high end market. All I am saying here is that by 1990 we were very well aware of the effects of AC line and power cable issues- and had been aware of them for some years prior. So I am still thinking that '1985' is about right.

All parts make have a sonic impact (caps, wire, resistors, transformers, even chassis, etc.). Some more than others. Silver and copper wire will sound different. How much of an improvement can only determined when you swap them out. There are better ways to filter AC than most conventional manufacturers use that probably would improve the sound much more that the cable.

Happy Listening.