Kurzweil PC3x

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The Kurzweil PC3 series of synthesizers is one of my favourites ever. Provides a massive amount of sculpting tools that can be combined like bricks to create your own synthesis architecture. You really create your own synthesizer into the PC3.

Creating for musicians

This page is a compilation of my personal contributions to electronic music through Kurzweil PC3 synthesizers series.

Music are emotions that are transmitted through sound, a good synthesizer provides the player with an almost infinite palette of sounds to produce emotions with which to paint their soundscape.

Creating those sounds is my passion.


Let's SoundsKape

Let's VA100 programmable pads for painting your musical landscapes.

Let's VA

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Powerful analog synthesizers with more than ninety parameters directly controlled from the PC3 panel.

Non official K2KFARM for PC3

K2KFarm is a vast compilation of high quality sounds created by Kurzweil in the 1990s for the K2000 synthesizer.

Here you can download some of the files that make up the compilation, converted, revised and adapted to PC3 synthesizers. It is a work in progress that will be updated as soon as the files are adapted.

AnaComps AnaLeads AnaPads
Bass Bells Brass
Digital Ensemble Ethereal
Guitars Hybrids HybPerc
K2KFacto Organs PnoEPno

4 Saw Versatile Compilation

Download 4 Saw Versatile4 Saw Versatile is a highly recommended minisynthesizer for those who wish to acquire notions of sound synthesis.

This compilation includes professional quality sounds and a handbook that explains the construction and operation of 4 Saw Versatile.

Piano Versátil

Download Piano VersatilPiano Versátil is a piano minisynthesizer. You can use the PC3 pannel to get from the sound of a harpsichord to a bass.

Acoustic pianos compilation

Download the Acoustic pianos compilationThis compilation includes all of my acoustic pianos, many of which have been developed from the Piano Versátil and Piano Versátil 2 minisynthesizers.

Digital pianos, harpsichords and bells

Download la colección de pianos eléctricos, claves y campanasA compilation of electric pianos, bells and harpsichords based on FM and other digital synthesis types for higher expressiveness.


Download sonidos de guitarraThis series is championed by a hybrid classical guitar sound inspired by the Yamaha SY99 synthesizer. It combines the accuracy of samples with the expression of FM synthesis.

A pure FM and various digital-synthesis-based guitar sounds are also included.

More original sounds

Pads Leads
Strings & Metals Basses



Any kind of sound synthesis process begins with a signal that varying its power by the time draws a shape, this shape can also be displayed inverting the time axis (frequency), the result is called Spectrum. The human auditory system acts as a spectrum analyzer, recognizing the sounds as "bass", "treble", "thin", "thick", "shiny", "dirty", etc.

Subtractive synthesis is to eliminate or reduce the power in a part of the spectrum of an original signal.

Subtractive synthesis is typically performed by different types of filters: High-pass, Low-pass, Band-pass, or Band-reject, all of that filters cut or "subtract" a portion of the spectrum and "leave passing" the portion that gives them the name.

In contrast, there is the additive synthesis, which is to broaden the sound spectrum by adding new frequencies. The most obvious way to do it is to play more than one instrument at a time (which makes any orchestra), in sound synthesis the procedure is to add instruments or oscillators, also the frequency modulation technique (FM), saturation (as in electric guitars), and others.

Generally, signals obtained by subtractive synthesis sound "cleaner" than the original ones, because there are less frequencies, while additive synthesis produces "dirtier" sounds.

Subtractive synthesis: filters

There are four basic subtractive filters: High-pass, Low-pass, Band-pass and Band-reject.

Filter parameters:

Cutoff frequency
Frequency (pitch) which is the boundary between what goes through the filter and what does not pass through the filter.
Band width
In band filters, the interval of frequencies that will be forwarded or suppressed by the filter.
The frequencies cutoff does not occurs abruptly but gradually. The higher the number of poles has a filter, the sharpest is the cut.
The resonance of a filter is a volume increase in the frequencies near the cutoff.

How they sound:

It is best to try. In analog waveforms (except sine), they produce a sharp change in sound timbre. The Lowpass produces the typical Wah Wah effect, the Highpass highlights the brilliance of sound, Bandpass makes the sound darker, the Band-reject makes the sound more slim and ethereal.

FM synthesis

FM was the first type of digital sound synthesis on a keyboard. Yamaha DX and SY (77 and 99) series where the pioneers. Some modern synthesizers still offer it as an option.

FM synthesis is a type of additive synthesis which consists of combining a series of identical operators, usually 4 or 6. These operators can connect with one another according to different schemes, so they work in two ways:

As an oscillator
It has no other operator in its input. Produces a sine waveform.
As an FM operator by itself
When receiving the output of one or more operators at its input.

Each operator has a sound input, an output and two control inputs. The sound produced at the output is similar to a sine, but is "stretched" or "shrunk" in any single moment depending on the input amplitude. The control inputs select the main amplitude and frequency of the output.

That kind of synthesis produces very expressive sounds, but it is not easy to use and neither suitable for accurate emulations of most of the acoustic instruments.

Modular synthesis

Modular synthesis is to have multiple devices, each one specialized in a kind of synthesis operation. The modules can be connected together using cables in many different ways.

Kurzweil's VAST synthesis is a virtual kind of modular synthesis.

Sample + Synthesis

It is the today's most used type of synthesis. Consists in a database of recorded real sounds. These sounds are passed through the synthesizer's parts.

This kind of synthesis can achieve very realistic emulations of acoustic sounds. The final result depends on the overall quality of the samples and the synthesizer's capabilities.

Parts and MIDI channels

MIDI is a communication protocol invented around the year 1980 for communicating up to 16 instruments amongst themselves, or to control that instruments by a computer.

As electronics have been deeply developed since the eighties, modern synthesizers can act as 16 separate instruments, each one of these virtual instruments is called a Part and is identified by the system by a MIDI channel number (1 to 16), each part only accepts MIDI orders addressed to its channel number.

Sequencing with effects

Effects in the PC3

  1. On one hand you have the Master Effect, consists of a compressor and an equalizer. This effect applies to everything you play.
  2. For everything else you have a total of 16 DSPs, which are like 16 separate sound chips.
  3. To a sound (Program) you can assign effects chains.
  4. What an effects chain does is to put an effect after another, each effect requires one or more DSPs, so a single chain can need many DSPs.
  5. Each one of the synthetizer's 16 parts has an active sound (Program) that is routed directly to an Insert effects chain, it can also be directed to two other chains that are shared by all the parts thru the Aux1 and Aux2 buses.
  6. Usually, the parts are claiming more DSPs than the synthesizer can provide, so there is a priority. Maximum priority is for the active part, after that, the priority of each part is higher the lower its MIDI channel number.

Applying effects to a sequence

If you want to improvise, first strategy is to use a few sounds and avoid those who claim more DSPs. The organs and electric guitars with realistic simulations of speakers and amplifiers are the usual suspects.

If you prefer a more serious approach, then you have to plan before playing instruments, a methodology could be:

  1. Think of the "environment" you want to create. So this is the chain for your shared bus Aux1.
  2. Think about whether there is any effect you want to share between different instruments but not all: it will be the chain in AUX2.
  3. Decide which are the main instruments that will show their best effects, and what instruments can sound "dry" or settle for sharing effects.
  4. Enter the Song mode.
  5. Select the instruments you will use on each track.
  6. Now it's time to fight with effects.
  7. FX screen displays the effect chain and the number of DSPs assigned to each part (channel). You can see the different parts moving the cursor from left to right: the number at the top right tells you the number of DSPs used by the Aux buses, the one at the left displays how many DSPs are been used by that part's insert effect.
  8. Parts that appears between parentheses are claiming for effects but there are no available DSPs for its priority. You can free resources choosing whether or not a part with higher priority claims for insert effects.
  9. On the AUXFX1 screen you can choose the effects chain you want for that bus overriding the default chain (which is the assigned to channel 1). The top number on the left tells how many DSPs needs the selected chain, and the top right displays the total number of DSPs used by the two Aux buses. You can select to send the signal of the Part, before (pre) of after (post) the insert effect to the AUXFX1 chain, as well the amount of signal sent.
  10. The AUXFX2 screen works exactly like AUXFX1 but is applied to the AUXFX2 bus.



A FUN is a controller, it controls dinamically the amount of alteration that a DSP prints to the sound, like an envelope or a LFO.

A FUN receives the value of two inputs and delivers the result of a mathematical operation on them. For example, a simple addition or multiplication. Inputs may be other controllers as LFOs, knobs, the velocity at which a key has been pressed, a constant value... or even FUNs with a lower number (after all a fun is also a controller).

There are countless uses. The question is: "I would like my sound did this, but there is no an speficic controller to it. It is possible with Funs?".

To design an appropiate function is very useful to use the program "Visual Fun, from MatKat Music.

Random controllers

Kurzweil synthesizers generate random numbers, but you need a Fun in order to control the speed at which these values ​​vary.

An LFO create a recurrent signal at specified frequencies, the frequency can also be handled by some other controller.

The sample & hold FUN take the value of the B controller only when the A controller reaches some value, so you can use an LFO to set the period in which a random value is taken:

FUN1: Sample B on A A: LFO1, B:RANDV1

and the problem is solved.

If you assign this FUN to the pitch at a rate of about three hertz, you can get the typical "computer of the 70's" effect, assigning a subtle value the sound is detuned and becomes more natural, with a high frequency and assigned to the amplifier you can get a thunder.

Now you know how to produce sudden random values, but you can also get a smooth drift reducing the value of the FUN to a little number and, after, adding the result to the immediately preceding value:

FUN2: A * B A:FUN1 B:0.10
FUN3: (A*Y)+B A:0.88 B:FUN2

This is good, for example for a wind effect.

"Analog" envelopes

When a natural sound dissipates in space or in time, their power and other characteristics are not lost proportionally (linear) but logarithmically. Analog synthesizers naturally reproduce this phenomenon but the digital ones do in linear way. Some people miss more "soft" and "natural" envelopes.

Logarithmic effect can be achieved by Kurzweil synthesizers by the high-pass filter function:

Fun1: HIPASS (F = A, B)

A is the cutoff value (0.02 to 0.05), B is the envelope to process, by example, AMPENV.

The function above extracts negative values from positive functions, to correct it is necesary to use another FUN:

Fun2: |A+B|, A=Fun1, B=0,5

Another functions to bend controllers

Generally, controllers that change their values linearly over the time give a sensation of mechanical precision. Controllers with curved shapes sound more organic and natural. Some suggestions:

B/(1-A), A=AmpEnv, B=AmpEnv
COS(A+B), A=0,50, B=AmpEnv
Fun1:(A+B)^2, A=0,48, B=AmpEnv. Fun2:A+B, A=Fun1, B=-0,22

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