One transistor headphone amplifier

At your risk, please take all known safety measures for your ears and headphones. How would a Pleiades Electra II amplifier sound with a Toshiba 2SK170 JFET? It seems ideal as it can give a 5mA quiesent current at 12V for class A operation (electrons flowing all the time). So music signal to gate through a potentiometer, amplified signal taken from drain by connecting 300 ohm headphones directly through battery plus and safety fuse.