Amp and preamp on same outlet?

Just how much of a no-no is this? ARC goes as far to print in their manual to say to have the amp and preamp on their own circuit. I live in an apt. and I'm forced to have both plugged into the same outlet. Cords just don't reach....How much sound quality is lost by doing this? It sounds great as is, but is there a major detriment to this? I'm curious.