dn-deobfuscator

reverse engineering tool for dn2prj project files and dn2pst preset files

Usage

The dn-deobfuscator tool can work with multiple file types:

• Elektron Digitone project files (.dn2prj)
• Elektron Digitone preset files (.dn2pst)
• SysEx files (.syx) with sounds/patches

Basic Usage

python -m dn_deobfuscator.app <file_path>

This will extract the contents of a .dn2prj or .dn2pst file to the current directory.

You can also extract all patches from a directory containing multiple .dn2pst files:

python -m dn_deobfuscator.app --patches-dir <directory_with_patches> --output-md <output_markdown_file>

This will process all .dn2pst files in the specified directory, extract their binary data, and create a consolidated markdown file with patches' names, tags, and hex dumps.

Command-line Options

usage: app.py [-h] [--file FILE] [--output OUTPUT] [--sysex SYSEX] [--md MD] [--patches-dir PATCHES_DIR] [--output-md OUTPUT_MD]

Optional Arguments:

• -h, --help - Show the help message and exit
• --file - Path to the file to extract (.dn2prj or .dn2pst)
• --output - Destination directory for extracted files (default: current directory)
• --sysex - Path to the .syx file containing Digitone patches
• --md - Path to output markdown file for sysex extraction
• --patches-dir - Directory containing .dn2pst patch files
• --output-md - Path to output markdown file for batch extraction

Examples

Extract a Digitone project or preset file:

python -m dn_deobfuscator.app path/to/mysound.dn2pst

This will extract the binary data and create a text representation in the current directory.

Extract a Digitone project to a specific directory:

python -m dn_deobfuscator.app path/to/myproject.dn2prj -d output_folder

Extract SysEx patches to a markdown file:

python -m dn_deobfuscator.app path/to/patches.syx -s

This will create a markdown file named patches.syx_patches.md in the current directory, containing all patches found in the SysEx file. Each patch will include:

• Patch name with prefix (e.g., "BD. KICK", "CY. CRASH")
• Patch tags
• Hex dump of the patch binary data

Extract multiple SysEx files to the same markdown file:

python -m dn_deobfuscator.app path/to/first.syx -s
python -m dn_deobfuscator.app path/to/second.syx -s -a

The -a (append) option allows you to add patches from multiple SysEx files to the same markdown document.

Extract SysEx to a specific directory:

python -m dn_deobfuscator.app path/to/patches.syx -s -d output_folder

This will create the markdown file in the specified output folder.

Batch extract multiple patch files from a directory:

python -m dn_deobfuscator.app --patches-dir data/dn2_patches --output-md patches_summary.md

This will:

1. Process all .dn2pst files in the data/dn2_patches directory

2. Extract each patch's binary file, text representation, and metadata (name and tags)

3. Generate a consolidated markdown file (patches_summary.md) with all patches in the following format:

   - patch name: <patch_name>
   - patch tags: <tag1>, <tag2>, <tag3>
   - patch binary:
   
   00000000  ac 11 d3 03 02 00 05 00  0f 30 30 32 38 00 00 00  |.........0028...|
   ...
   

Progress on Digitone 2 Preset Reverse Engineering

• Created functional test for parsing the "HIDDEN TEARS" Digitone 2 preset file
• Implemented parse_digitone_preset function to extract sound parameters
• Identified the correct offset for the algorithm value (0x69)
• Successfully parsed basic parameters from the binary file
• Added detailed comments explaining parameter locations

Parameter Locations Identified

• Algorithm value: offset 0x69
• Feedback value: offset 0x83
• Filter parameters: around offset 0xA0-0xB0
• Amplifier parameters: around offset 0xB0-0xC0
• FX parameters: around offset 0xC0-0xD0
• LFO parameters: around offset 0xD0-0xF0

Next Steps

• Identify exact offsets for more parameters
• Implement conversion functions for floating-point values
• Add support for more preset files to validate the offsets
• Create a comprehensive mapping of parameter names to offsets
• Implement a function to modify parameters and save them back to the binary file
• Build a user interface for visualizing and editing presets

Sound Preset Parameters

This section documents the sound preset parameters found in Digitone 2 based on our reverse engineering work and the Digitone 2 User Manual.

SYN Parameters (Page 1/4)

Parameter	Possible Values	Description
ALGO	1-8	FM Algorithm (arrangement of operators)
C	0.00-1.00	Carrier operator level
A	0.00-1.00	A operator level
B	[0.00-1.00, 0.00-1.00]	B1 and B2 operator levels
HARM	-26.00 to +26.00	Harmonic value - negative values change operator C, positive values change A and B1
DTUN	-48.00 to +48.00	Detune value
FDBK	0-127	Feedback amount
MIX	-64 to +63	Mix value between carrier outputs X and Y

SYN Parameters (Page 2/4)

Parameter	Possible Values	Description
A Envelope	{ atk: 0-127, dec: 0-127, end: 0-127, lev: 0-127 }	A operator envelope
B Envelope	{ atk: 0-127, dec: 0-127, end: 0-127, lev: 0-127 }	B operators envelope

SYN Parameters (Page 3/4)

Parameter	Possible Values	Description
ADEL	0-127	A Delay value
ATRG	true/false	A Trig (on/off)
ARST	true/false	A Reset (on/off)
PHRT	"ALL", "OFF"	Phase retrigger mode
BDEL	0-127	B Delay value
BTRG	true/false	B Trig (on/off)
BRST	true/false	B Reset (on/off)

SYN Parameters (Page 4/4)

Parameter	Possible Values	Description
Ratio Offset C	-16.00 to +16.00	Carrier ratio offset
Ratio Offset A	-16.00 to +16.00	A operator ratio offset
Ratio Offset B1	-16.00 to +16.00	B1 operator ratio offset
Ratio Offset B2	-16.00 to +16.00	B2 operator ratio offset
Key Track A	-64 to +63	A operator key tracking
Key Track B1	-64 to +63	B1 operator key tracking
Key Track B2	-64 to +63	B2 operator key tracking

Filter Parameters

Parameter	Possible Values	Description
Type	"Lowpass", "Bandpass", "Highpass" with 2-pole (12dB/oct)	Filter type
Attack	0-127	Filter envelope attack
Decay	0-127	Filter envelope decay
Sustain	0-127	Filter envelope sustain
Release	0-127	Filter envelope release
Frequency	0-127	Filter cutoff frequency
Resonance	0-127	Filter resonance
Env Amount	-64 to +63	Envelope amount (bipolar)

Amplifier Parameters

Parameter	Possible Values	Description
Attack	0-127	Amp envelope attack
Decay	0-127	Amp envelope decay
Sustain	0-127	Amp envelope sustain
Release	0-127	Amp envelope release
Reset	true/false	Reset flag
Mode	"ADSR", "AD"	Envelope mode
Pan	"Left", "Center", "Right"	Pan position
Volume	0-127	Output volume

FX Parameters

Parameter	Possible Values	Description
Bit Reduction	true/false	Bit reduction enabled
Overdrive	0-127	Overdrive amount
Sample Rate Reduction	0-127	Sample rate reduction amount
Sample Rate Routing	"Pre-filter", "Post-filter"	Routing mode
Delay	true/false	Delay enabled
Reverb	0-127	Reverb amount
Chorus	0-127	Chorus amount
Overdrive Routing	"Pre-filter", "Post-filter"	Overdrive routing

LFO Parameters

Parameter	Possible Values	Description
Speed	0.00-127.00	LFO speed
Multiplier	1, 2, 4, 8, 16, 32, 64	Speed multiplier
Fade	0-127	Fade time
Destination	SYN parameters (HARM, DTUN, FDBK, MIX), FLTR parameters (FREQ, RES), AMP parameters (PAN, VOL)	Target parameter
Waveform	"Triangle", "Sine", "Square", "Sawtooth", "Exponential", "Ramp", "Random"	Waveform type
Start Phase	0-127	Start phase
Mode	"FREE", "TRIG", "HOLD", "ONE", "HALF"	LFO mode
Depth	-64.00 to +63.00	Modulation depth

Note: Parameter values are based on both our reverse engineering of the HIDDEN TEARS preset and the official Digitone 2 User Manual.