I currently have a musical fidelity v can 2/ v90 dac combo connected to my pc, my headphones are cheap sennheiser that i bought for £50. I have a budget of around £500 to improve my set up, should i just try and buy the best cans i can afford? or look at a better amp and can combo? I was planning on spending the money on speakers for my main set up but with the birth of our liitle girl most of my listening is with my headphones on.