*level 3 / POWER CABLE
8 AWG is a bit overkill for a phono stage, yes. That doesn't mean that it won't sound good, or that you won't like the effect.
Phono stages have an absolutely constant power draw (unlike power amps) so you don't need "uncompressed power delivery" either. For example, Audioquest splits their top cords into high-current, large gauge versions and smaller-gauge source versions for this reason. So instead of buying a massive gauge that's not needed for the application, you can move up the line into a smaller gauge that uses higher quality metals.
Not to be "bashing" cables, but lets's address the OP's question. Is it worth spending money on a high end 8 AWG power cable to feed his Parasound JC3+ phonoo pre amp (the same unit I have in my system). The specs show the power draw by the JC3+ are +/- 0.1 amps. Feeding with a cable rated to carry 30 amps, or 300 times the power required, could only be a giant waste of money. Open mind, closed mind, doesn't change the math. Amazed how often this same question gets kicked around on this forum.
Thanks for coherent answer @mulveling. That is all I needed. The rest of the usual cable bashing type of responses is indeed absolutely tiring. If I am in an audiophile forum and I am asking about this specific case, is because I DO believe in cables. And every single time I have upgraded cables in my system, I have heard a clear difference. I had the opportunity to get one of these 8 AWG from a friend, so I was wondering if there could be any negative effect given the unnecessary gauge. That is all. So let's focus on answering questions, rather than telling posters cables are for ignorant people. Just move on.... lots of time in your hands it seems...
Common sense and first listen, would suggest that this may be an overkill, but you may also find out that after many hours of use it is not the case. It depends, while personally i would go 14awg for a phono stage, others would prefer a lighter awg but that's normal too. Whatever you do leave it for a while, then you can be sure.