OverviewJISBOS = JFET Input Stage, BJT Output Stage
Initially this discrete class-A buffer was developed to upgrade the output stage of the SOHA headphone ampflifier. It can be used to upgrade output stages of line drivers or headphone amplifiers. It may be used as a standalone headphone amp (without a voltage gain stage) when fed by a modern source (CDP) with at least 2V output voltage and meant to drive low impedance (32 Ω) headphones.
Thanks a lot to Ti Kan (aka amb) contributing his design for free to the DIY community.