DDRM Expander

Successful Build : 04/2019

tech:

it adds an envelope controllable Ring Modulator, Chorus, Tremolo, Delay, and Reverb effects. It is designed to work seamlessly with Deckard’s Dream, but it also works as a standalone audio effects device.

Schematics:

DD-EXPANDER-SCHEMATICS-REV1.zip for rev.1.0

BOM:

DD-EXP-BOM-REV1.0.1.pdf latest version for rev.1.0 and YOU MUST ADD 2x TL071 and 1x 4.7uF MLCC capacitor RM5
DD-EXP-BOM-REV1.0.0.xlsx (Old version) for rev.1.0

For all DDRM Expander : remove the 6N138 and buy 6N139 to avoid Midi issues (stucking notes)

BOM LATEST BOARD VERSION INFO

rev.1.1 changes

the new PCB Version is 1.1 !! (midi noise fixed)

it use following changes which affect the above BOM, you have to respect this:

IC33 and IC37 is TL071 (DIP8)

C166 not in BOM 4.7uF ceramic (MLCC) RM5

latest firmware

ExpanderMK1_2.0.hex

It's for all Expander versions

DDRM Expander VC Placement Guide V2 from Kevin Looney:

DDRM Expander VC Placement Guide V2.pdf

DDRM FAQ and Build tipps from Todd

Deckard’s Dream Expander FAQ and Build Guide V1-7.docx

Trimmer Values (was requested by a user)

SIG= 501 = 500Ohm

REF: 201 = 200R

0.2Khz =103 = 10K

2.5k = 103 = 10K

Further Build Infos (was requested by a user)

Distance between Panel and Slider/control PCB = 10mm

Distance between Controlpcb and analog pcb = 12mm

MIDI-NOISE FIX pictures:

only for DIY PCB Version 1.0

is fixed in DIY PCB Version 1.1

If you want a fix of your factory assembled Version, contact me

Click expand for Pictures from rev1.0 pcb Modification FIX

Addional pics 2021:

Power LED Installation:

remove the 12V LED from the Card PCB and drill a 4,5mm hole in the frontpanel - which is the standard size for 3mm LED-holders (available in most electronic shops)