Bunsen, I was using 5VSB of my Antec NeoPower 650 Blue for my Digital Audio mobo but eventually after time it started loosing power under extreme load and right after power button press.(same thing happened with the first, second and third PC PSUs I was using with it) So, I went to the local PC shop to get an old AC->DC PC notebook adapter of acceptable specs, but I never ended up adding it. Thing is, while using a 400Mhz PII clocked to 533 during my DA's downtime I had a spur of the moment urge to replace it with a newer PC mobo to run OS X and windows and such.(I also did not fancy spending loads on an old GF6800GT when a muchmuch better PCI-e card was not much more)

That was late Feb and now here I am still using my Antec PSU and massively overclocked OS X running PC with absolutely no issues at all even with much higher power requirements.

I am about to put my DA back into service as a NAS device soon however. I need somewhere to store all my Mac stuff when I switch over my desktop to linux and windows use and have OS X on an Acer Aspire One that should be arriving next week.

So, I would always advise that anyone make sure to get something to handle the G4's rather high standby+FW+ADC or whatever requirements instead of relying on the PC PSU's 5VSB.