Another one of Bajaman’s many amp emulator circuits. It emulates the frequency response of the classic Vox AC30 top boost channel, including power amplifier emulation. It’s designed to fit in a 125B with top mounted jacks. Schematic and discussion on FSB here.
The input buffer stage uses a 2SK117 JFET with DGS pinout, but I’ve throw in an extra pad to use JFETs with GSD pinout (J201, 2N5457, etc). If you’re using the 2SK117 you won’t need to populate the jumper by Q1, but if you’re using a GSD pinout transistor, you will need that jumper.
