Alesis D4
Drum Module (1991)

 

Digital rackmount module based on PCM samples features 12 analog trigger inputs controlled by DYNAMIC ARTICULATION technology.

RACKMOUNT single rack unit. Main panel features a 16 X 2 lcd lines display, 12 push buttons, a data encoder and a preview trigger (non-dynamic) pad.

Back panel terminals connectors:
- main signal output
- AUX output
- 12 jack triggers inputs
- footswitch input for hit-hat control or assignable to other functions
- headphones (front)


Power supply is external AC-AC type 9V / 830 mA original is P-3.

TECH main core is a 8-bits 8031 / 80C31 MPU which manages 16 voices polyphony - converter DAC is a common 16 bits Burr-Brown PCM54. The D4 sound generation is based on plain PCM samples on the ROM wavetable assigned to a Midi note or a special trigger.

The basic sound architecture is the KIT (a kind of patch) composed by up to 61 PCM samples shots.

 

WAVETABLE internal mask ROMs contain 541 PCM waveforms at 16 bits resolution - most are mono-sampled but some are stereo natives.

bassdrum (x99) snare drum (x99) cymbals-hihats (x55) tom toms(x92) FX effects(x80) percussion/chromatics (x76)

INTERFACE EDIT classic nineties programming with submenus.

EDIT basic sound parameters includes panning, pitch tuning and analog out assignment following 4 configurations:

- A: 2 stereo pairs - B: 1 stereo - C: 2 mono - D: 4 mono.

TRIGGERS each sound is assigned to one of 12 trigger inputs based on custom DYNAMIC ARTICULATION system technology, compatible with most trigger systems.
Some dedicated trigger parameters matches the drummer playmode behavior:

- sensibility adjustment - 8 velocity curves - decay time - crosstalks: a threshold gate filters nearby pads vibrations (PIC)

MIDI the drum brain works also with standard Midi system but the implementation is rather poor offering just a few Midi CC# like volume, pitch bending and program change.
Check out full Midi Parameters LIST.

 

MEMORY:

- 21 RAM user kits Kits and configuration are saved to SRAM memory - data can be backup to Midi exclusives datas. Battery replacement: 3V BR-2325 lithium battery soldered to mainboard, replacement involves soldering - click LEFT for bigger picture -

OS lastest version is 1.4 burnt in a single 64 Kb EPROM 8 bits model TMS27C512.

- DOWNLOAD LATEST FREE BINARY -

MAINTENANCE 2 typical issues as machine ages:

- LCD missing some lines - ALPS data wheel encoder getting unprecise - clean it - or change it.

RELATED MODELS:

- DM-5 (1996) updated D4 at 18 bits resolution DAC and 500 sounds VIDEO - DM-6 (2009) VIDEO - DM-10 (2012) VIDEO

VST PLUGIN / SAMPLED VERSION there is no official D4 VST plugin, however some free samples collections:

1 full set sampled free D4 samples FREE DOWNLOAD

 

ADVERT GALLERY:

advert	hires pic