JAN6418 portable Triode Headphone Amp MkII

The finished (second) headphone amp is assembled in a slim durable plastic enclosure lined top and bottom with bituminized heavy Al foil. You can see the lithium battery, printed cct. brd. and 6.5mm stereo phono sockets. In this build the stereo phono sockets have double pole double throw switches which are all employed, including the “real” switch. The switches make only when both devices are plugged into the amp. The idea is if you do not have devices plugged into both input and output and have the switch on then the unit is “off” with no battery drain. The battery is lithium so expensive bit I should get 80 to 100 hours of play out of this little portable triode headphone amp. See the JAN6418 Valve (Tube) Preamplifier / Headphone Amp Kit project page for full details.