I just bought a pair of Stax SR-80 electret headphones along with the SRD-4 energizer (SR-84 system) and would like to avoid using them with a full-size (loudspeaker) amplifier if I can avoid it, since I have a couple of decent headphone amps. (Creek OBH-1 and Audio Alchemy class A headphone...

I repurposed the planar magnetic tweeters from Monsoon MH-500 speakers ($20-$40/pair on ebay) to make planar magnetic headphones: https://sites.google.com/site/ralphgonz/music-monstein-headphones They have some colorations in the upper bass and not the sharpest stereo focus, but they sound...