Basics of Synthesizers (9) – PCM Synthezisers (Pulse Code Modulation)

Hello! This is Jooyoung Kim, a mixing engineer and music producer.

Today marks the final article in my ‘Basics of Synthesizers’ series. I may add more articles in the future if I come across interesting topics, such as modular synthesizers (which I’ve recently started exploring—stay tuned!). For now, however, I feel I’ve covered enough to complete this category.

Let’s start!


The PCM (Pulse-Code Modulation) method is essentially a form of digital sampling that represents analog signals through discrete digital steps. While modern virtual instruments load massive recorded data into RAM to trigger sounds via MIDI, hardware PCM instruments utilize ROM in much the same way—storing high-quality, pre-fabricated waveforms that are ready to be played instantly.

Because these instruments play back pre-recorded samples from internal memory rather than synthesizing them from scratch or recording new ones, they are commonly called Romplers (a blend of ROM and Sampler). Unlike pure samplers, Romplers focus on the immediate reproduction of realistic acoustic and electronic sounds, making them the backbone of music production since the late 1980s.

Implementing such a system requires significant computational power and memory resources. Thanks to rapid technological advancements, these requirements were finally met in the late 1980s. During this period, ROM prices decreased significantly, allowing for the emergence of instruments installed with long-cycle samples, which offered a level of realism previously unattainable.

The Kurzweil K250 was the forerunner and the first PCM-based synthesizer.

These instruments utilized samples of each sound phase—attack, decay, and release. This approach allowed them to produce more realistic and dynamic sounds. Many people requested authentic sounds and in the 1990s, these kinds of instruments became mainstream.

The PCM method is now the standard for recording systems, DAWs, and virtual instruments. You might assume that modern virtual instruments are simply evolved versions of PCM-style synthesizers, and that is largely true. However, as many musicians today find themselves missing the characteristically thin and lo-fi sounds of vintage PCM hardware, many software companies now provide these classic instruments in digital formats.


The Korg M1

The Korg M1 was a famous PCM-style synthesizer in the late 1980s. It became one of the best-selling synthesizers in history. Its specific presets, such as the M1 Piano and Organ 2, defined the sound of 1990s house and dance music. These sounds were so distinct that they are still widely used in modern electronic music productions.

The M1 also featured external card slots, allowing users to expand its sound library by inserting PCM and Program cards, providing additional waveforms and presets beyond its internal memory.


The E-mu Proteus Series

The E-mu Proteus series were also famous PCM-style synthesizers in the late 1980s. Unlike the Korg M1, they were rack-mount module swithout a keyboard. they were designed to provide high-quality samples at a lower price point, making them standards in many project studios. Their presets were widely used in film and television scores, including the iconic whistling sound in The X-Files theme.

The later models of the Proteus series were also highly expandable; they featured internal slots where users could install additional ROM SIMMs, such as the Orbit or Mo Phatt cards, to instantly add hundreds of new sounds tailored to specific genres.


The Roland JV-1080 and JV Series

In this perspective, you should know about the Roland JV series. The JV-1080 and 2080 are legendary icons of the Rompler era. Released in the mid-1990s, these units became industry standards, found in almost every professional studio worldwide. Their massive success came from their ability to provide high-quality, ready-to-use PCM samples through various expansion boards, allowing musicians to access realistic orchestral, synth, and ethnic sounds instantly without the need for complex sampling.

This picture shows sound expansion slots of the JV-1080 synthesizer

You can hear the sounds of the official Roland Cloud recreation of the JV-1080 in this video, as demonstrated by ADL-MusicLab. It’s easy to associate these sounds with 1990s and 2000s classic pop, TV commercial soundtracks, and film scores.


The Korg Trinity and Korg Triton

The Korg Trinity and Triton were also iconic instruments of that era. Beyond hip-hop, these workstations defined the sound of mainstream pop. For instance, The Neptunes were among the most famous users of the Triton, while the instrument’s distinctive patches were also featured in many of Britney Spears’ hits. These units weren’t just for one genre; they were the great tools for producing the global hits of the early 2000s.

Similar to the JV series, the Triton also offered expandability through EXB-PCM boards and even allowed for the addition of the MOSS synthesis engine.


The Yamaha Motif

The Yamaha Motif was another famous instrument of the era. It produced more realistic sounds than its competitors, so its Acoustic Piano, Rhodes (E. Piano), and Acoustic Guitar presets were widely used in churches. In particular, it became a standard keyboard for global worship teams like Hillsong and Bethel, defining the sound of modern gospel music. The Motif stood out for its PLG expansion boards, which allowed users to add entirely new synthesis engines, such as FM synthesis, directly into the unit. (In South Korea, the Motif is still widely used in worship services.)


Interestingly, the thin and lo-fi quality of these sounds has become a source of classic pops. If you want to recreate an authentic vintage pop vibe, I highly recommend exploring these types of virtual instruments.

With this, I would like to conclude my ‘Basics of Synthesizers’ series. I have put a lot of effort into researching and explaining these concepts, and I hope you found them helpful.

Thank you for reading, and I will see you in the next article!

Basics of Synthesizers (8) – Phase Distortion Synthesis

Hello! This is Jooyoung Kim, a mixing engineer and music producer. Today, I’ll talk about the phase distortion synthesis method and synthesizers.

This post includes a few affiliate links. If you make a purchase through them, I may receive a small commission, which helps me keep writing…^^

In my last post, “Basics of Synthesizers (4) – Modulation Synthesis and FM,” I mentioned that Yamaha’s DX7 was called an FM synthesizer, but in reality, it uses phase modulation synthesis. Also, I already explained the phase modulation in short. Therefore, I will not discuss phase modulation further.

However, there is one more signal synthesis method, Phase Distortion (PD), invented by Casio, which uses the phase of the signal. Its principle is similar to that of Phase Modulation, which was invented by John Chowning.

The picture illustrates how the PD method works. First, you can see that the basic frequency counter resets to zero after a certain period – (a).

There is also another frequency counter with a slightly higher frequency than (a), which resets to zero when the (a) signal resets to zero – (b).

(b) signal is used the phase value of the sine signal – (c).

The inverted base signal (a), which is used as a windowing function that goes to zero at the end of the period -(d).

The final output signal obtained by multiplying (c) by (d). This multiplication levels out the sudden jump in (c), resulting in a smooth, filtered PD waveform – (e).

The Casio CZ series was the hardware synthesizer to which the PD method was applied.

The Casio XW series also featured the PD method in its synthesis engine.

Phase Distortion (PD) method hardware synthesizers are not sold by other companies besides Casio. Therefore, if acquiring the real hardware is too expensive or inconvenient, using software emulations like Arturia’s CZ-V is a handy alternative.

That’s all for today. See you in the next post!

Basics of Synthesizers (7) – Granular Synthesis

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Hi! This is Jooyoung Kim, a mixing engineer and music producer. Today, I’ll introduce granular synthesis, which is composed of “grain” units.

The principle of this type of sound synthesis is very similar to the concept of sampling. Granular synthesizers take small parts of a sample and store them as units. Those units are called “grains.” That is where the name “Granular Synthesis” comes from.

The grains have lengths ranging from approximately 1 to 100 ms, and these samples can be played at different times, phases, speeds, and frequencies in a granular synthesizer. Thus, cloudy sounds that resemble long reverberations and continuous tails are produced by these manipulations.

In 1947, Dennis Gabor introduced this concept, which was first implemented in a computer in 1974 by Curtis Roads, an electronic music composer specializing in granular and pulsar synthesis. The spans are quite long, aren’t they?

The emergence of granular synthesizer hardware was significantly delayed due to the large computational requirements and high CPU speed needed for the calculations. Thus, the real-time version of this synthesizer emerged 12 years after the use of granular synthesizers in Curtis Roads’ music.

The real-time granular synthesis was invented by Barry Truax, a Canadian composer. This synthesis was processed by the DMX-1000 computer.

Naturally, you might wonder about the existence of physical hardware, as with other synthesizers. The upper photo shows the modern, dedicated granular synthesizer hardware, the GR-1, which was released in 2017.

This shows that this kind of synthesis processing requires a lot of computing resources. And this means that many virtual synthesizers using this method require significant computing power.

However, for implementation in DAWs (Digital Audio Workstations), no physical hardware is needed to use granular synthesis. Arturia’s EFX Fragments is a great example.

Output’s “Portal” plugin is another excellent granular effect.

This is the official video of the EFX Fragments. You might hear the “shimmering sound” from it.

This sound could be effective in ambient music that requires long tails on the sounds. I like these sounds, but I’ve never used them in my music… ^^;; However, someday I will…

OK, I’ll wrap this up today. See you in the next post!

Basics of Synthesizers (6) – Vector Synthesis & Wavetable Synthesis

Hey there! I’m Jooyoung Kim, a mixing engineer and music producer.

Ugh… English has been killing me lately. Seriously… 😭

I wish it would just sink into my brain step by step, but it feels like I’m cramming it in, and my head’s about to explode. Words, especially, are the worst. Haha.

Anyway, with my schedule being so tight, I’m finally getting around to writing this on the weekend.

It’s been a while, but I’m back with another post on synthesizer basics! 😊

Today, we’re diving into vector synthesis and wavetable synthesis.

Ready? Let’s get started!

(By the way, if you make a purchase through the links in this post, I may earn a small commission, which helps me keep the lights on and keep creating content!)


Vector Synthesis

Vector synthesis was a fresh concept introduced by Sequential in the 1980s with their Prophet VS synthesizer.

Prophet VS synthesizer. You can see the joystick on the left.

This method assigns different sound timbres to the four corners of a square. Using a joystick, you can intuitively blend these sounds together! The resulting sound, created by mixing these four sources, can be represented as a single point on a coordinate plane using vectors—hence the name “vector synthesis.”

(If you took physics as an elective in high school, this concept might feel pretty familiar!)

Yamaha SY22
Korg Wavestation

Later, Sequential was acquired by Yamaha, and the development team moved on to join Korg. This led to the release of two vector synthesizers: the Yamaha SY22 and the Korg Wavestation.

Arturia has a virtual instrument called Prophet-VS V.

Korg also released a virtual version of the Wavestation, bringing its advanced vector synthesis system to software.

If you’re curious about vector synthesizers, these are worth checking out!


Wavetable Synthesis

Wavetable synthesis actually predates vector synthesis by a bit. It was first utilized in MUSIC-II, a sound design program developed by Max Vernon Mathews in 1958. It was later commercialized by PPG with their Wavecomputer 360 in the late 1970s and the Wave series in the 1980s.

The concept? It’s about mixing different waveforms to create new sounds. It’s somewhat similar to vector synthesis, in that both methods interpolate between different timbres to generate a sound. That’s why I’m covering both in the same post! 😄

The key difference is this:

  • Vector synthesis calculates the volume balance between four sound sources based on their position in a coordinate plane.
  • Wavetable synthesis works within a single waveform cycle, calculating the amplitude ratios of different waveforms.

This distinction should help clarify how the two approaches differ.

Also, you might notice that both vector and wavetable synthesizers let you tweak the ADSR (Attack, Decay, Sustain, Release) parameters independently. If you’ve read my earlier post on subtractive synthesis, you’ll know I mentioned that these parameters are pretty universal across synthesis methods.

If you’re feeling a bit lost, check out that post for a primer on using something like a Minimoog. Most synths don’t stray too far from that foundation, and trust me, you’ll end up using a Minimoog sound in a track at least once in your life! 😄

Waldorf has recreated the PPG Wave as a virtual instrument, bringing back its iconic 80s sound.

There are tons of wavetable synths out there—Serum, Waves, the free Vital, and LANDR Synth X, to name a few. My personal recommendation? Go with Serum. It’s got a huge user base, which means tons of presets and a great community. Plus, it’s just well-designed.


A Few Final Thoughts

The thing about vector and wavetable synthesis is that you can’t pin down their sound to something specific like sine, triangle, square, or saw waves. Throw in a bunch of different sounds, and the output changes dramatically. Unlike FM synthesis or analog subtractive synthesis, it’s hard to describe the “typical” sound of these methods. 😅

Personally, I love messing around with synthesizers to craft the perfect sound, but it can be a time sink. My advice? Start with a preset that’s close to what you’re after. (If you familiarize yourself with basic waveforms like sine, saw, triangle, and square, it’ll be easier to figure out which category your desired sound falls into.) Build your track first, then tweak the sound later to get it just right.


That’s it for today! Thanks for reading, and I’ll catch you in the next post! 😊