ANDROMEDA DELUXE NATURAL OVERDRIVE
6
BUILD NOTES
JFET selection
The original ODR-C uses the 2N5486 (MMBF5486) JFET for Q1, which is no longer in active
production. This is very similar to the 2N5457, which is available from Aion FX in SMD format pre-
soldered to through-hole adapter boards and will perform identically in this circuit.
Transistor selection
The original ODR-C uses European-convention BC549C transistors for Q2 and Q3. These are still
readily available, but the Andromeda Deluxe uses the footprint for the USA equivalent 2N5088. If you
want to use the BC549C, rotate them 180 degrees from the PCB footprint since their pinout is reversed.
Both types will perform identically in this circuit.
Using SMD JFETs
Most general-purpose JFETs are no longer available 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 surface-
mount devices 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.
The BJT transistors (Q2/Q3) also have an extra SMD pad for the collector, so SMD transistors can be
used in the same way, although BJT transistors are still very easy to find in through-hole format.
Capacitor substitution
Due to parts availability, some of the larger film capacitors may be unavailable, particularly the two
2.2uF capacitors (C6 and C27). The original ODR-1 used electrolytic capacitors in these positions and
you can use them here too if you want. In both positions, the positive leg should go in the top pad and the
negative in the bottom.
