Roland D-50 Linear Synthesizer (1987)

 

The D50 is one of the greatest all-time sales along with Korg M1 and Yamaha DX7.

L.A synthesis: hybrid sampled PCM short waveforms and generated synthesis.

KEYBOARD 61 velocity keys with aftertouch.

Main panel features a 2 x 40 lines display, 54 buttons, a data entry slider and a data card slot. On the left side there is a joystick lever for modulation.

Back panel terminal connectors:
- main signal out
- headphones out
- Midi interface
- 2 pedal expression assignable to tone mix/aftertouch/ modulation
- 2 pedalswitch inputs assignable to patch change / chase / portamento

 

 

TECH main core is a 8-bits CPU CMOS UPD78312 manages 16 voices polyphony - relative DAC is a Burr-Brown model HP54HP. LA synthesis WG Wave Generator is a mix of 2 syntheses:

- 2 Digitally generated basic waveforms sawtooth & square wave, a kind of primitive VA - PCM wavetable

L.A STRUCTURE HIERARCHY L.A minimal part is the PARTIAL composed by 2 UPPER tones + 2 LOWER tones then 4 combined tones make a PATCH; TONE has value for relation between both partials and each partial is like an oscillator with various synthesis chain elements.

WG (voice) + TVF (filter) + TVA (amplitude)

WAVE GENERATOR is a 128 kb ROM (at IC29-30) PCM wavetable + a digital waveform generator. In total there are 101 sound waves available:

- 47 Transient PCM acoustic - 29 Transient PCM spectral loops - 23 Transient PCM normal loops - 2 digitally generated sawtooth and square wave

ALGORITHMS the WG combines partial synthesis elements with a digital ring modulator in 7 possible pathways or algorithms: (p= pcm sample / s= digitally generated wave)

ALG P.1 P.2 2 partials Combination diagram 1 S S mix partial 1-2 2 S S mix partial 1 + Ring modulator 3 P S mix partial 1-2 4 P S mix partial 1 + ring modulator 5 S P mix partial 1 + ring modulator 6 P P mix partial 1-2 7 P P mix partial 1 + ring modulator

 

PERFORMANCE parameter CHASE is a delay mode between the tones with 3 directions modes:

- Upper -> Lower - Upper -> Lower -> Lower - Upper ->Lower -> Upper PATCH can be played also with a legato with variable portamento time.

 

FILTER structure is based on the TVF -time variant filter- which is a digital 4-poles resonant lowpass filter.

TECH filter has a restriction: TVF does not act on a PCM element, later possible on V-synth D50 emulation. Hear Filter assigned to aftertouch

LFO 3 delayed modulators (shapes: saw, triangle, random and square) and 3 destinations:

- LFO to amplitude - LFO to pulse width - LFO to filter cutoff Hear LFo

ENVELOPE 2 main EGs:
- EG1 amplitude : 5 segments + 5 times
- EG2 filter : 5 segments + 5 times.
All partials have their own EG for both amplitude + filter, for a total of 4 TVF EGs and 4 TVA EGs.

 

 

EFFECTS 2 dedicaed chips (87136+87137) handles 32 reverbs echoes + 7 chorus modulations + 1 simple serial -12 dB EQ with HIGH settings boost (250 Hz) or a LOW boost (63 Hz) + Q-emphasis.
Effect can be balanced with dry / wet parameter to different tones in 3 modes:

- mono tones with stereo reverb - stereo tones with stereo reverb - stereo Tones with reverb to upper or lower tone. Hear Reverb delay

MIDI quite basic but full MIDI exclusives is implemented with full support of edit and data dump.

MAINTENANCE the D-50 usually suffers from dead key contacts: get q-tips and cleaning solution to wash both contacts and strips and pay attention to remove also possible cotton debris. Aftertouch is more critical and may need more attention to fix the sensors.

battery replacement D50 common keys issues

D50 repair tutorial video

 

 

MEMORY
- 64 RAM internal patches
RAM is doubled if using cards m-256E or m-256D.
Battery replacement: a CR-2032 lithium battery in holder.

- click for bigger pic comparison -

 

D-50 RELATED MODELS:

D-550 expander version with same characteristics	PG-1000 dedicated D50 programmer	VC-1 card is a D-50 emulation for V-synth
D-10 another member of the LA family.	MT-32 consumer version of D-10 series	MEX EXPANSION board enhances D50 functions

 

 

EDITOR many computer-based softwares are available:

- D50 librarian (PC donationware) PIC - Soundquest (MAC/PC $$) - EMC D50 editor manager (Atari ST) PIC - Roland D50 parameter editor (Commodore Amiga) PIC - DR.T editor (Atari ST) - Synth works (Atari ST) PIC - D50 manager (Atari ST) PIC - CTRLR (PC/MAC free) PIC - D50v (VST editor) PIC - coffeeshopped (IOS editor) PIC

 

VST PLUGIN / SAMPLED VERSION there are some free and commercial samples set:

KR AUDIO

200 MB free SAMPLES

 

 

DEMO: advertising : 1 Famous: 1 - Demo: 1 Pad: 1 - 2 - 3 - 4 - 5 bell : 1 - 2 organ: 1 - 2 - Synth: 1 - 2 - 3 - 4 - 5 - 6 - 7 Bass: 1 - 2 Ambient: 1 Noise: 1

MANUAL

SERVICE MANUAL

DOWNLOAD FACTORY SET + 5000 patches

OS EPROM FIRMWARE DUMP

original Brochure

original Brochure

original Brochure

original D50 case

Custom D50
by custom synth UK

D50 cat