I have found that Grace makes a very good headphone amp that will handle most headphones easily. I also found that Peachtree headphone amp to be just OK. However, your ears will tell you whether it is worth it or not. BTW, I also have a very small 9volt headphone amp that I replaced the op amp in that sounds surprisingly fantastic and was cheaper than a dime store piece of candy. It easily sounds better than many headphone amps I've owned that cost tons more. So, your options may not be just inline with pricier products for a noticeable improvement.