New S12G-550 louder than 3 year old stock video card

[cerbie]

Just got a new build together. The important bits are:
Silverstone PS07B
2x Noctua NF-S12A-PWM
Thermalright Macho
Gigabyte Windforce GTX 460 (carried over, has 2 fans about 80mm)

Until swapping out the case fans, the stock ones were the loudest things in there, running at full speed. Upon installing the Noctuas, I was expecting the GTX 460 to be the loudest component, until I went about replacing it.

Instead, it's the power supply, a brand new Seasonic S12G-550. I can hear it from over 10 feet away, just sitting at the desktop, with basically no load. It's new, but sounds like it should be several years old, with distinct ball bearing buzziness (my previous S12 and S12II supplies tended to just have some clicking, until they got older). The Antec Neo Eco 520W that it replaced, also a few years old, is, right now, much quieter, and not audible, much less annoying, from such distances.

Did I have too high expectations, or is there something up with the fan in my sample, worthy of an RMA?