Drumulator 8-fold Sound Expansion to DIY

by mLab.midisoft.de

The sound sets are selected with the drumulator buttons 1-8 & ENTER.
Therefore no drilling or additional switches are required.

Die Auswahl der Soundsets erfolgt über die Drumulator-Tasten 1-8 & ENTER.
Daher sind keine Bohrungen oder zusätzliche Schalter erforderlich.

You can order the complete upgrade kit here while stocks last

ready to install

Drumulator 8-fold Sound Expansion MOVIE

To switch through the 8 sound sets, (MOVIE)
Hold down one of the 8 number buttons and press ENTER.
The following sound sets are available.

Here's a pdf file to download and print out (please do not scale)
stick it beneath the numbers 1 ... 8


Assembly of the circuit boards

Schematics & Boards

You can order the bare circuit boards here for

€ 50, - including free shipping within the EU

Drumulator Sound Expansion DIY PCB-Set

Sound Expansion board

Qty Parts Package Description Value
4 1E,3E,4E,5E DIL28 Socket CMOS EPROM 27C512
4 1E1,3E1,4E1,5E1 DIL28 Socket CMOS EPROM 27C512
1 ENTER-BUTTON Wire Pad 1-Way Through-Hole to Drumulator D18 Cathode
1 SV1 Male Header 3-Way to 12k Sytem ROM board
2 6D Male Header 4-Way to Drumulator IC 6D
2 9J/10J Male Header 4-Way to Drumulator IC 9J and 10J
2 C1, C2, C3 Capacitor SMD 0805 22n
1 C3 Capacitor SMD 0805 100n
2 D1, D3 Diode Through-Hole 1N4148
2 IC1, IC2 DIL14Socket Quad 2-input OR 74LS32N
1 IC3 DIL14 Socket Hex Inverter 74LS14N
1 IC4 DIL16 Socket Quad D Latch 4042N
1 IC5 DIL14 Socket Quad 2-in NAND 74LS00N
2 R1, R4 Resistor SMD 0805 82k
2 R3, R5 Resistor SMD 0805 10k
1 T1 Transistor NPN (B-C-E) 2N5172

System Expansion board

1 12K DIL28 Socket CMOS EPROM 27C512
1 SV1 Male Header 3-Way to Sound Expansion board

MIDI board

1 MIDI DIL08 Socket Opto Coupler 6N138 or 6N139
1 SV1 Male Header 3-Way to Drumulator IC 13F
1 JP1 Male Header 2-Way to MIDI Jack
1 D1 Diode Through-Hole 1N4148
1 C1 Capactor SMD 0805 100n
1 R1 Resistor SMD 0805 220 Ohm
1 R2 Resistor SMD 0805 1k

Wiring & mounting

The Sound Expansion board

1. Wiring

Header name = 6D
Pin1 to EMU IC-6D pin3
Pin2 to EMU IC-6D pin4
Pin3 to EMU IC-6D pin5
Pin4 to EMU IC-6D pin6

Header name = 9J/10J
Pin1 to EMU IC-9J pin13
Pin2 to EMU IC-9J pin14
Pin3 to EMU IC 9J pin15
Pin4 to EMU IC-10J pin12
ENTER_D18-CAT wirepad to EMU Diode D18 cathode (near by the ENTER switch)

2. Mounting

The expansion ROM board chip socket 5E has a Long Pin header (straight forwards except PIN 1, 27, 20, 22)
Plug this header into the EMU IC socket 5E and fix the board with an UNC4-40 spacer under the appropriate mounting hole.

The System ROM board

1. Wiring

Header name = SV1
Pin1 to Sound Expansion IC-4 pin2
Pin2 to Sound Expansion IC-4 pin10
Pin3 to Sound Expansion IC-4 pin11

2. Mounting

The system ROM board chip socket 12K has a Long Pin header (straight forwards except PIN 1, 26, 27)
Just plug this header into the EMU IC socket 12K

The MIDI IN board

if your Drumulator has no MIDI IN yet, the System ROM supports MIDI IN for all 8 sound sets.

1. Wiring

Header name = to IC 13F
Pin1 to EMU IC-13F pin7
Pin2 to EMU IC-13F pin 12+13 (bridged)
Pin3 to EMU IC-13F pin14

Header name = MIDI
Pin4 to MIDI IN jack pin4
Pin5 to MIDI IN jack pin5

2. Mounting

Fix the MIDI board through the mounting hole with an UNC4-40 spacer near by EMU IC-13F

3. Using

To set a MIDI In channel (1 ... 16)
PRESS and hold the EXTERNAL CLOCK button.
The display shows EC 01, where 01 is the selected MIDI channel.
Use the < > buttons to change the MIDI channel.

To activate the MIDI IN Mode
PRESS and hold the EXTERNAL CLOCK button then press the RUN / STOP button
The display turns off.
MIDI IN is active now.

To leave the MIDI IN Mode


The ROMs

9 x 27C512[64k]

Each of the 2 Sound ROM sets (1E, 3E, 4E, 5E) & (1E1, 3E1, 4E1, 5E1)
contains 4 Drumulator sound sets.

The Sytem ROM (12k) contains individual operating data for all 8 sound sets

Sound ROM-Set 1

(Electric 1, Analog, Latin, Jazz)
1E.bin Sound ROM (2F32) Checksum
3E.bin Sound ROM (7B4F) Checksum
4E.bin Sound ROM (96A2) Checksum
5E.bin Sound ROM (CE2C) Checksum

Sound ROM-Set 2

(African, Rock, Electric 2, Factory)
1E1.bin Sound ROM (5BDF) Checksum
3E1.bin Sound ROM (5694) Checksum
4E1.bin Sound ROM (8BD0) Checksum
5E1.bin Sound ROM (1957) Checksum

Sytem ROM

12k_MIDI.bin System ROM (7F40) Checksum

ROM address assignment


Sound ROM addr

System ROM addr

[ROM Set 1] 1E,3E,4E,5E [12K]
Electronic 1 0000-3FFF 0000-1FFF
Analog 4000-7FFF 2000-3FFF
Latin 8000-BFFF 4000-5FFF
Jazz C000-FFFF 6000-7FFF
[ROM Set 2] 1E1,3E1,4E1,5E1  
African 0000-3FFF 8000-9FFF
Rock 4000-7FFF A000-BFFF
Electronic 2 8000-BFFF C000-DFFF
Factory C000-FFFF E000-FFFF