Edit 7/30/17: PCBs are now available at the XRKAudio Etsy Store! For real! Up until now there have been hardly any portable Class A head amp designs, commercial or DIY. Here's a brand-new CMOY-sized amp project with the goods! I'll be building a couple of these in the coming weeks and will post my build pics and listening impressions here. Until then, here's some info on the little beast: An experienced amp builder on the DIYAudio forums, xrk971, with the input of the ever-helpful community over there, is currently finalizing his design for this amp. In the works are a detailed bill of materials for the build, a circuit schematic, and hopefully a GB (on DIYA, not here!) for printed circuit boards (design courtesy of user BDHM)...all to be found in this thread: http://www.diyaudio.com/forums/head...2-based-se-class-headamp-without-heat-11.html "X" has run extensive simulations of this circuit as well as real-world measurements for THD and FR, and the results look stellar. Low noise, textbook-perfect harmonic distortion profile, and a razor flat frequency response. Solid bass. Plenty of juice, even for 250 Ohm cans (possibly higher). And most importantly... according to him, it sounds amazing. It runs slightly warm to the touch, and gets 4-5 hours of battery life. What makes it most exciting to me is that it's noob-friendly, with a low parts count, and all through-hole components except for the JFETs. My solder-slinging experience is limited to much simpler things like speaker crossovers and volume pots, etc., but I think even I'll be able to pull this off. I'm excited about this little amp project!