Roland D-Series Linear Arithmetic Synthesisers

As part of their march into the fully digital synthesiser era Roland released the Roland D-50, the first in the series of synthesisers that would become known as the Roland D-series.  While all these synthesisers carry the 'D' in their name both the notional flag ship synthesisers in this range were very different to each other and the other synthesisers that were release.

The Roland D-Series consisted of 7 core synthesisers in the late 1980's plus a boutique synthesiser the Roland D-05 released in 2017.

The original Roland D-Series synthesisers were:

• Roland D-5 (1989)

• Roland D-10 (1988)

• Roland D-20 (1988)

• Roland D-50 (1987)

• Roland D-70 (1990)

• Roland D-110 (1988)

• Roland D-550 (1987)

The first thing you notice, when the synthesisers are listed like this is that the Roland D-Series synthesisers were not released to market in name order.

As stated above the first Roland D-Series synthesiser that was released was the Roland D-50 in 1987.  Although Roland had developed this synthesiser over several years since the released and dominance of the digital Yamaha DX7 digital synthesiser in 1983.  Was it just a coincidence that both the Yamaha DX7 Mk2 and Roland D-50 were released in 1987.  Yes, the Yamaha synthesiser was an improvement on the Mk1, the Roland synthesiser took the market by storm due to the Linear Arithmetic (LA) synthesis that Roland had developed which was seen as easier to programme than the FM method used on the DX7.  This would be the basis of the Roland D-Series synthesisers and other Roland synthesisers released over the years to come.

Linear Arithmetic synthesis, simplistically put, uses a very small sample often referred to as a Pulse-Code Modulation (PCM) to generate the start of the tone.  It then uses digital processes to create the tone that is then heard by the musician.  (Digital parameters that can be adjusted include waveform, pitch, envelope, filters and effects.)

The Roland D-50 came with a dedicated programmer (Roland PG-1000) which allowed the musician to develop the tonal capability of the server.  Although many of the first adopters of this synthesisers mainly used the stock sounds as they were 'new' and 'fresh'.

After the release of the Roland D-50, Roland released a 2U 19" rack mounted version of the synthesiser (Roland D-550).  This has the same capability of its sibling just requiring a MIDI connection to drive the tones not the keyboard.

The following year the Roland D-Series range was expanded with the released the Roland D-10 and Roland D-20.  Both synthesisers were based on the same LA Synthesis concept.  But were not as programmable as the Roland D-50.  This is re-enforced by the fact that Roland issued a different hardware programmer for this synthesiser (Roland PG-10) which had a much simpler user interface reflecting the reduced parameter set of these two synthesisers.

Many people on the internet have called the D-10 and D-20 as 'baby' or 'stripped down' D-50's.  I would dispute those views.  The Roland D-10 and D-20 were more workstations based on LA Synthesis as opposed to a pure synthesiser which is what the D-50 was.  These instruments came with Drum / Rhythm Machines.  The D-20 also included an 8 track sequencer and a disk drive to allow tones and sequences to be stored and recalled.  The disk drive was the main oversight from the D-50 and would have made the instrument more versatile in my view.

The next Roland D-Series instrument to be released was the Roland D-110.  This was a 1U 19" rack mount module of the Roland D-10.  Many have compared this instrument to the D-50.  But its architecture shared its linage with the D-10 and D-20 as opposed to the D-50.  It used the same synth features and menus, shared the PG-10 programmer and the same SYSEX files shared lineage with the Roland D-10.  

The Roland D-110 provided 6 additional outputs for the musician to route tones from the instrument. This feature that was not present on the D-10 and D-20.

While the Roland D-110 has dedicated rhythm tones which can be driven from a seperate MIDI channel it is not what I would consider a rhythm machine.  Finally the Roland D-110 does not have a sequencer or floppy disk drive.

Referring to the Roland D-Series synthesisers discussed thus far.  The Roland D-50 was the better synthesiser, however the Roland D-20 was the better all-around workstation.

In 1989 Roland release the Roland D-5.  This was a stripped-down version of the Roland D-10.  It used the same LA synthesis generation engine as the D-10.  Did not have sequencer, effects or rhythm capabilities.  I have also never been able to get the Roland PG-10 programmer to work with the two examples that I have borrowed over the years.  

The Roland D-5 was the least functional instrument in the Roland D-Series and in my view not a synthesiser to add to your collection.

The final Roland D-series synthesiser to be released was the Roland D-70 billed as Super LA Synthesis.  Arguably the name could be described as borrowing lots of artistic licence. Released in 1990 this synthesiser was in development as the next synthesiser in the Roland U-series.  However, the Korg M1 was launched in 1990.  The Korg instrument also used PCM but came with all the functionality of a workstation.  The Roland D-70 was rushed into market and billed as the answer to the Korg M1, which history has shown it wasn't.

The biggest give away that the Roland D-70 should not have been a Roland D-Series synthesiser is the Roland U-50 logo found on the motherboard inside the instrument.  The musician could not alter the creation of the tone and had limited editing capability on the filters used at the end of the tone creation process.

The Roland D-70 bought the Roland D-Series to an end.

The Roland D-Series move the company from an analogue synthesiser company (whether the tone generation was VCO or DCO) to a digital synthesiser company.  It also set the path for other instruments to follow.  e.g. the Roland R-8 and Roland R-5 drum machines use the same  PCM sample based tone generation and digital to analogue converters (DAC's) developed for the D-Series.