I tried many power amplifiers as headphone amplifiers, first with QUAD 405 in 1981! I never experienced that they work better as headphone amplifiers than NJM4556, although they have unlimited current capacity as far as headphones are concerned. In fact 4556 sounded better then any of power amplifiers when used for headphones. If two 4556 are connected in parallel as in O2 they have enough of current capabilities for any headphones.
I don't say that Wayne Kirkland's HP amp is not worth building. I am sure that it is, but for the novice who wants to try something simple NJM4556 will be great first build.
I don't say that Wayne Kirkland's HP amp is not worth building. I am sure that it is, but for the novice who wants to try something simple NJM4556 will be great first build.