So, possibly stupid question, but I'm new to this.
I'm currently running a pair of 2PACs at 150MHz with Raspberry Pi controlling them. I can tell ample power is a constant issue. I have one clearly substandard USB hub that is powered, but only has a 2 amp power supply. If I try to run both 2PACs on it, eventually one drops out. I can however run 1 off the Pi unit itself, and one off the hub. But that is less than ideal, especially since I'd like to clock them higher.
I have another powered USB hub that is not compatible with Raspberry Pi, but which has a 3 amp power supply. On a scale from "Go for it" to "You're gonna fry you 2PACs", how bad of an idea is it to just use the 3 amp power supply with the hub that normally uses a 2 amp power supply?
Alternately, I did order a Sipolar 10 port HUB, so I could just wait for that to eventually show up from China, but I've caught the bug a bit...
I think there are a lot of unknowns with your question. It is hard to make a judgement call regarding your hub and 3A power supply. One of my concerns would be does your hub and power supply both use barrel connectors or micro/mini USB? If it uses a barrel connector, you need to ensure that your polarities match between the two and that they are the same size.