SUPER simple double delay effect! My goal was to build the most compact, zaniest delay possible using only a handful of components. The result is an enclosure-less, easily-modifieable noise machine with a suprisingly massive sound.

UPDATE: Details about the new 3d-printed enclosure at the bottom!

Step 1: Supplies/Tools

1. 2 x PT2399 reverb module (no preamp)
2. Plastic storage box dividers (for pseudo-enclosure)
3. 4 x #6 - 32 x 1.5” screws + 12 nuts

Tools:
Soldering iron/ solder
hot glue gun/ hot glue
Wire/wire strippers

Components:
2x ⅛” jacks
2x 100k potentiometers
DC jack
SPST switch

Step 2: Overview

The idea is simple- we’ll simply solder a jack to the input of one board, whose output will be wired to the input of the other. The output will come from a jack soldered to the output of the second board.
We’ll also add a 100k potentiometer to each board, which allows for control of the delay time.
Both boards can be powered by a single DC jack supplying 9v. I wired the DC jack center negative so that it can be used with standard guitar pedal power supplies.

Step 3: Prepare Each Board

Locate R27 on each board. With an exacto knife, cut across the trace between the chip and the resistor. When the boards are attached, the bottom of each board will face each other with the mix knobs on opposite sides. The allows the potentiometers to be located right by the points on the board to which they’ll be soldered.

Step 4: Hot Glue Jacks and Potentiometers

Making sure that the components will be out of the way of the screws when the boards are attached, hot glue the jacks and potentiometers to the bottom of the board to which they’ll be wired. Each board will have a jack and a potentiometer in identical spots on the board, with the pins of the pots located right next to the three points on the board to which they’ll be wired. Put a small piece of electrical tape on the board beneath the pots to prevent them from shorting the points on the board.

Step 5: Wire Jacks and Potentiometers

The jack on one board will be wired to the input, the other to the output.

Step 6: Wire 9v Jack and Power Switch

The jack and switch only need to be wired to one of the boards. Once everything is constructed, we’ll wire the the boards' power inputs together using the the blue screw connectors on the boards.

Step 7: Wire the Boards Together

Almost done!
Solder a wire from the + pin at the output of board one to the + pin at the input of the other.
Attach the boards together and secure in place using the nuts.
Wire the ground pins of the input and output jacks together.
Wire the + and - power inputs of each board together using the blue screw connectors.

Step 8: Finishing Touches

Using the plastic dividers, mark and drill holes for the components to build the ‘sides’ of the psuedo-enclosure.

Step 9: Extensions/Mods

demo of the deluxe edition: https://youtu.be/zYZJL4VZQ9U

A few ideas for additional possibilities! Here are some notes for the mods featured on the Double Delay Deluxe. I added a few more plastic dividers and a piece of plexiglass on the top to accomodate the new components.