Thanks for all the replies guys! Went to bed after posting and got up expecting a few views and no replies. Surprise!

The sticker on the power supply only mentions one 12V rail, with a total power of 1200W available (100A). I was using the 4 PCIe connectors out of the supply to connect to each of of the connectors on the Avalon, ie, not using the double headers at the miner end.

I'm in 240V land.

I'm using a couple of HP DPS-1200 power supply on a pair SP20s, so I might swap out the Avalon for one of the SP20s. Reason I got this Thermaltake power supply is the SP20s are at work and I only go in to the office a couple of days so it was easier to get the A6 up and running.