Whats the minimum hard hardware I'd need (or something I could buy since I've not very good at kit making) for putting an infrared blaster on a raspberry pi.  

I run an old yamaha amp in a cupboard with a rasppi for volumio for input (plus fm).  I'd like to be able to control the volume, input and or on speakers via the pi.

I can probably nut out the software side and any coding I'd need, but couldn't figure out what hardware I'd need.  Preferably I'd like the IR transmitter on a short cable - although it's possible it will reflect off the white cabinet doors.

I do have a usbuirt I'm not really using (usb connected multi receiver and transmitter) that I guess would have linux drivers.

I also I think, have an old hauppauge ir blaster ina box somewhere (2.5mm plug I believe).