Moon LaNDer

A follow-up to the Little Jim, after a forum member asked whether the LND150 depletion-mode MOSFET would make a quieter distortion. It does: noticeably less hiss than the BS170.

The circuit. Three common-source LND150 gain stages in series, then a two-band James-style EQ, which is more flexible than a single tone control and makes it easier to match to an amp. The LND150's low input capacitance means the guitar can feed the first stage directly, with no buffer.

Each stage runs at about −0.8 V gate bias and 200 µA, the sweet spot for a waveform rich in second harmonic, and with no gate current there's no blocking distortion. The devices matched to within 50 mV.

Less gain than the Little Jim: clean to mid gain rather than heavy distortion, and responsive to playing dynamics. Raising two drain resistors adds about 6 dB, into classic lead territory, which could go on a switch.