Just bought Mad Dog + Leather ALPHA Pads + Comfort Strap. Using at my desk at work playing music through my laptop. Laptop does not have anything special sound card-wise. Was not driving well. A friend had a Penguin Amp. That has made a huge difference as I've tried it. I'm wondering if I should get just an AMP? or a DAC/AMP combo? I'm pretty new to this....budget? Somewhere around $100 if possible....but could go up if it would make a huge difference. Recommendations? Thanks.