GAIA PREAMP DRIVE MK. II
5
BUILD NOTES
Using SMD JFETs
The MPF4393 JFET is no longer available from the original manufacturer in through-hole format.
This PCB uses a hybrid through-hole/SMD outline for each JFET. An extra “G” (gate) pad is included to
accommodate the MMBF4393 surface-mount version without the need for adapters.
SMD JFETs should be oriented as follows:
All surface-mount JFETs use the same pinout, so this configuration will fit any type that we’re aware
of. However, always check the datasheet if you’re uncertain—they’re difficult to desolder if you make a
mistake.
MPF4393s from Aion FX
We have a large quantity of
through-hole MPF4393
and should be able to provide them in hobbyist
quantities for the foreseeable future. They are available in sets of 5. They are manufactured by ON
Semiconductor, the same as those used in the original Catalinbread pedal. They test in the same range
and will perform identically.
All manuals and user guides at all-guides.com
