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3. Digital Potentiometer (U3): The expression upgrade comes with two different digital
potentiometer ICs. One is labeled MCP41050, which is a 50K ohm pot. The other IC is labeled
MCP41010, which is a 10K ohm pot. We suggest using the 50K digital pot (MCP41050) in
most cases, but we provide the optional 10K pot because some newer pedals will perform
better with this value (most Line6 pedals perform better with this 10K pot, for example).
The digital potentiometer is installed into an 8-pin socket on the board so we’ll install this socket
first. This IC is polarized so make sure to install these parts in the proper orientation. Align the
little divot on the socket with the divot shape printed on the board. The divot should be facing
the ceramic cap (121). Hold the socket in place as you tack down a pin on the back (122).
Make sure the socket is flush with the top of the board and solder the rest of the pins in place.
Once the socket is installed, press the digital pot IC into place. The divot on the IC should line up
with the divot on the socket, facing the yellow cap (123).
121
122
123
4. DIP Switch (S3): Install the DIP switch the same way you did on the main board. Line up the printing
on the switch with the printing on the board. Solder it in place (124).
124
