Does anybody know where I can find a female wall socket ....

I would think that a 20 amp industrial grade duplex recptacle from home depot would except a stranded #8 wire. You might have to put half the strands on one side of the screw the other half on the other side. If you look at the receptacle you will see what I mean. It is designed to capture the wire. Another option would be a crimp on spade connector #8. This will reduce the size for easy make up on any receptacle. I recommend industrial grade 20 amp recptacle bare minimum.

you or sicker than i am. 10 gauge is more than enough. contact fim cables. they sell beefy outlets. brianw on here can tell you how to contact them. what are your electronics?

I have a 100 Amp sub-panel for my audio only, panel location in the middle of the back wall. The wiring for the 120 VAC 20 receptacles is 6 gauge ran in rigid conduit. The wire runs are only around 7 feet, ran into the larger metal mount boxes, and pigtailed there to 10 gauge, which will easily fit into any better quality outlet. My electrician, (the Father in Law), is a Electrical Contractor, isn't into audio, and thinks that we are ALL crazy! I didn't ask him if the FIM had the space required for an 8 gauge wire, though it may. You may want to contact FIM engineering and ask them.

Why did I use 6 gauge? Like I said, the Father in Law is a contractor, specializing in heavy industrial/commercial. It's kind of fun snooping around the warehouse ...

If you use the larger mount boxes, you can "pig tail" down to the size that WILL fit. A BandAid? Maybe, but it sure works better than the 12/3 that it replaced. The addition of the better quality receptacles is well worth the money. Choose wisely.