MRG LPF/a Assembly Guide

The MRG LPF/a uses only through hole components.

Its build should be considered of medium difficulty given the number of components and steps required.

Theory of operation:

  1. Build the Main PCB.
  2. Build the Front PCB.
  3. Module assembly.

Main PCB build

Step A1. Start by soldering all horizontal resistors and the diode.

lpf pcb

Step A2. Solder all ceramic capacitors.

lpf pcb

Step A3. Solder the AS3320 IC and the 2x5 pin header. If desired, a 18-pin socket can be soldered on the PCB, instead of directly soldering the IC.

lpf pcb

Step A4. Solder the TL072 ICs. If desired, 8-pin sockets can be soldered on the PCB, instead of directly soldering the ICs.

lpf pcb

Step A5. Solder the four PP Capacitors.

lpf pcb

Step A6. Solder the electrolytic capacitors.

lpf pcb

Everything apart from the two 14-pin headers are soldered on the board now. It is time to solder the front PCB.

Front PCB

Step B1 Check the alignment of the PCB (label U1 is the top row), arrange the jack sockets and the potentiometers.

lpf pcb

Step B2. Solder the components. Tip: in order to be sure to align the components to the front panel, install the front panel as in photo below and solder the components on the back.

lpf pcb

Step B3. Solder the socket headers. Tip: In order to align the Main PCB's pin headers to the Front PCB's socket headers, assemble the two PCBs together, as in picture, and solder them in place.

lpf pcb

All soldering is now done! The next step is installing the front panel.

Final Module Assembly

Install the front panel, using nuts and washers to keep it attached, and add the knobs to the potentiometers.

Congratulations! You have concluded a fairly complex build!

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