We had Dan Smalle of Bottlehead over to listen to his latest creation. This is a beautiful 845 based headphone amp. We also tested several other models. It is very interesting that different types of headphones react so radically different to different type of headphone amps. I don't really think that you can judge the performance of either the headphone or the headphone amp without trying them with a wide variety of products. It was very educational to say the least.