You could try a second-hand KnCMiner Neptune, they are pretty quiet.
+1
No sound at all except the quiet crackling of the flames.
I think one of the issues with using a single cable at way too high of power is not necessarily the wire diameter, but the pins. In my experience, depending on what quality of PCIE pins and ends you have the pins get really hot, melt the ends, and catch them on fire. If you know what parts you have in the cables and on the board you might (maybe) be ok, but if you don't then it's a fairly high statistical probability of a fire.
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novak