Ces Software VST Instruments

Ces has released four VST instruments that cover a range of synthesis methods. They include a subtractive virtual-analog synthesizer (cesSynth1 1.4),

Ces has released four VST instruments that cover a range of synthesis methods. They include a subtractive virtual-analog synthesizer (cesSynth1 1.4), an additive synth modeled after a drawbar organ (cesSynth2 1.3), a drum synth (cesSynth5 1.0), and a frequency modulation (FM) synth (FMHeaven 1.1). The first three plug-ins sell for $20 each and differ from the demo versions in that they offer sample-accurate synchronization. FMHeaven ($50) also adds sample-accurate sync, and lets you load Yamaha DX-7 patches. The commercial and demo versions can be downloaded at the Ces Web site.


FMHeaven is the newest and most sophisticated of the Ces synths. It offers six oscillators and a full modulation matrix, which means each oscillator can modulate any other one, including itself. That amounts to billions of algorithms — quite an enhancement to the original DX-7's 32 FM algorithms. However, as you'll quickly see when exploring the factory patches or third-party DX-7 banks, a little FM goes a long way — a typical patch uses only a few modulation routings.

Like the DX-7, FMHeaven uses a variant of frequency modulation called phase modulation (PM). The results are nearly identical, but for technical reasons, PM is much easier to control. However, I will refer to the synthesis method as FM throughout this review.

FMHeaven's control panel is organized in six rows corresponding to its six oscillators. The two knobs on the left control coarse- and fine-tuning, and the small button at the far left turns keyboard tracking on and off. When keyboard tracking is off, the tuning value is shown in hertz; with tracking on, it is shown as a semitone value offset from the note being played. For example, in Fig. 1, tracking is off for Oscillator 4 and the value is 4 Hz, while tracking is on for Oscillator 1, which is set to a 19.01 semitone offset.

The grid next to the tuning buttons represents the modulation matrix. The grid is organized by row and column; each row represents one of six possible carrier waveforms and each column represents one of six modulators. The number showing in each cell represents how much the row's carrier waveform will be modulated by the column's waveform; in the example, Oscillator 2 modulates Oscillator 1 by 82 percent. FMHeaven's modulation scaling has been designed to match the DX-7.

Each oscillator includes a four-stage, Velocity-sensitive envelope with separate level and rate controls for each stage. Each oscillator also has keyboard scaling of volume, which is very useful for damping artifacts caused by aliasing in the upper registers. (FM can easily produce harmonic components above one half the sampling rate.) Finally, there are separate level knobs and mute buttons for each oscillator. Enveloping and keyboard scaling are premodulation, while output level is postmodulation.

Each patch has its own tuning, Pitch Bend range, and LFO. The LFO can be mono or multi. (Multi uses a separate LFO for each voice.) When mono, the LFO can run free or retrigger with each Note On. There are three LFO waveforms: sine, square, and random. The random LFO in multimode produces interesting polyphonic sample-and-hold effects. The Depth knob or MIDI CC 1 (Mod Wheel) controls the LFO amount.

FMHeaven is multitimbral and polyphonic. Each of 16 MIDI channels can have a program and 64 notes of polyphony. The front panel always shows Channel 1's program; the programs on Channels 2 through 16 must be selected by MIDI Program Change messages. With 16 channels each playing 64 notes, FMHeaven could theoretically play more than 1,000 notes — of course, your CPU would have something to say about that.

FMHeaven can import DX-7 banks. It reads banks in packed bulk dump format, which is the format used by thousands of online patch banks. (You can download a Zip archive containing a large selection of DX-7 banks at ftp://byrd.math.uga.edu/pub/music/dx7/dx7patch.zip.) I imported and played dozens of DX-7 patches while writing this review. They sounded authentic (though I did not have a DX-7 for comparison). In some cases, high Velocity values caused noticeable aliasing, but I edited that out of the patches by adjusting the Velocity sensitivity of one or more envelopes or by altering the oscillators' keyboard scalings.


Ces includes a few unusual twists for cesSynth1, its virtual-analog, subtractive synth (see Fig. 2). For starters, each oscillator's waveform is a mix of pulse, sawtooth, and triangle waves. Furthermore, the pulse wave's width and the sawtooth's symmetry (from ramp-up through triangle to ramp-down) are variable. Finally, Oscillator 2 can be synched and frequency modulated by Oscillator 1.

Each oscillator has a voltage control section for varying its pitch by any combination of MIDI Pitch Bend, triangle LFO, and two four-stage envelope generators. The oscillators have separate voltage-controlled amplifier sections, and any combination of the LFO and envelope generators controls the amplifier's level. Finally, there is a 4-pole resonant lowpass filter with a cutoff frequency that can be controlled by the LFO or either envelope generator. The final output is a mix of the filter and oscillator signals.

The envelope generators are more flexible than standard ADSRs because the ramp times and the sustain levels can be varied. There are separate Velocity sensitivity controls for level and ramp time, and all level controls are bipolar. (The instrument uses a three-dimensional envelope graphic to indicate the Velocity range.) CesSynth1 offers three modes of operation: mono (with variable portamento), polyphonic (64 notes), and arpeggiated (with variable portamento).


CesSynth2 is a drawbar-organ simulation, but like cesSynth1, it has a few added special features (see Fig. 3). Those include an ADSR amplitude envelope, a resonant lowpass filter, and an auto-panning feature (for example, a pan LFO). When auto panning is off, a drawbar's pan position can be set independently. Finally, the nine harmonics can be doubled, which adds a second, detunable oscillator.

Among cesSynth2's more traditional features are Click and Percussion controls. The Click effect is preattack and ranges from 0 to 30 ms; using it adds noise to the start of each note, which simulates a drawbar organ's switching noise. The Percussion effect gives a sound a slightly wooden quality and can be applied to the 4-foot or 2⅔-foot pipe. Percussion applies a fast attack/slow decay envelope to all notes played with times ranging from 0 to 500 ms. If you have a Leslie-simulation plug-in or external effect, try it with CesSynth2's effects.

CesSynth2 provides 64-note polyphony, but like all additive synths, it can suck up CPU cycles fast. Setting all detuning and pan controls to zero reduced this load by nearly 30 percent on my G3/300 MHz system.


The final synthesizer in the Ces collection is cesSynth5, a drum synth capable of playing 16 user-programmable drum sounds (see Fig. 4). It operates in a slightly unusual way in that its drum sounds are automatically mapped to the 16 MIDI channels — the MIDI note number used to play the sound is irrelevant. That makes programming drum sounds a little tricky, because selecting a sound for display on the control panel does not automatically change the sound.

Each cesSynth5 drum sound consists of two variable-waveform oscillators plus a noise generator. Each oscillator has a start and end pitch control with an additional control for the pitch-change rate. The oscillators and the noise generator all have volume envelopes with sliders for total duration and for the level at four equally spaced intervals. Those controls allow you to develop interesting sounds with pitches and levels that evolve over time.

A sound's output stage features a resonant lowpass filter as well as controls for output volume and pan position. There are also controls to adjust the effect that note Velocity has on filter cutoff and output volume.


The Ces synths are 64-note polyphonic except the drum synth, which offers 32 notes of polyphony. Each synth's control panel is clearly laid out, but fine-tuning the knobs and sliders can be a delicate task. One nice feature is the information display, which shows each parameter's description and numerical value as it changes. The synths' documentation is sufficient to get you up and running, although a bit more detail would be helpful in some cases.

FMHeaven is obviously the star performer of the Ces VST-instruments show, and the fact that it's able to read DX-7 patches alone makes it a worthwhile addition to your soft-synth toolkit. But all of the synths can make interesting sounds, and all of them offer low latency, which makes them extremely playable. The affordable price and the demo versions of these software synthesizer plug-ins make them well worth considering.

Minimum System Requirements

Ces VST Instruments

MAC: 604e/200 processor; 64 MB RAM; host software supporting VST instrument format

PC: Pentium II/100 or Athlon-class processor; 64 MB RAM; host software supporting VST instrument format


Ces Software
VST Instruments (Mac/Win)
software synth plug-ins



PROS: Easy to use. Cost-effective. Can produce a wide variety of sounds.

CONS: Panel controls often difficult to fine-tune. Limited documentation.


Ces Software
e-mail cferrari@dial.pipex.co.uk
Web www.loftsoft.co.uk