Angus' sound is quite simple and pure. Basically, get a Marshall, I have an AVT100 and can get his sound easily but you could get an even better Angus sound with a higher end Marshall that's actually all valve. His sound is much cleaner than what you'd expect. You can either turn the volume right up on the clean channel or put very little gain on the overdrive channel. Then set the tone controls however you like coz different guitars are different but roughly bass-4, midd-5, treble-6.