my macbook only has two usb ports, which is not enough for my dj needs with t scratch pro, but in order to have more USB ports i need a hub, which would need to be powered,
BUT when i turn up at a venue i only want to plug in the power supply for my laptop, SO what is the thinking on whether, with a little crafty soldering, i could make use of the currently unused FW port on my laptop to power a USB hub so i can add more control options?
You would need to put a 5 volt reg in between the 12.8 V that the firewire puts out and the power supply input to your hub but yeah firewire can supply enough curren 8 full power usb ports.
but on a macbook, pins 1 (live) and 2 (gnd) on a firewire port, output unregulated between 9V and 13V with the max load you can draw from that being <1A
USB hubs tend to require a regulated 5V supply, so using the above regulator to stabalise and limit the voltage, i can make a powersource for my usb hub fed by my FW port (or at least thats the plan)