I was wondering if it was possible to drive a pair of regular dynamic headphones from a power amp such as my Class A F5. Sometimes I have periods of time without a pair of speakers such as if I have sold them and looking for something new to replace them with. In the meantime it would be nice to use a pair of headphones which quite frankly are hard to beat with most speakers. It seems that you need to spend quite a few more in pennies on the speakers to match even a modest pair of cans and once you are in the realms of higher end headphones then most speakers don't come close to the same levels of enjoyment and immersion in the music.
I found a neat little project over at ESP. It is nothing more than a 6 resistors, 3 per side to give the correct voltage levels and impedance to the headphones. You could probably solder these resistors in-line with the headphone to speaker banana leads and heatshrink them but I used a small box, proto-board to hold the resistors and some nice nylon sleeving.
Using the F5 as an headphone amp sure beats the usual puny op-amp circuits and it can drive even the lowest impedance cans which some circuits struggle with. The circuit can be adjusted to suit the headphone impedance.