8008 to Peavey410E cab (cable)?

[the diplomat]

This may be a ridiculus question, but are different cables supposed to be use to connect a Marshall 8008 amplifier to a Peavey 410E cabinet, or any other rack setup as far as that goes? I had a cable running for years with a Black and white wire running to the 1/4 connectors. Today I needed to lengthen them so I cut a 20 foot cable in half to make two 10 footers out of a guitar chord. One black wire to the tip of the connector and the ground to the sleeve. Not long after the cables begain to heat up and I finally blew a transistor inside the 8008. Is there a specific type of cable I should be using? Any type of reasoning on this subject would be greatly appreciated.

Thanks
The diplomat.