Alesis QUADRASYNTH S4 Plus
QS Composite synthesis - PCM

About

Alesis QUADRASYNTH S4 Plus is a PCM synthesizer with 20MB waveform ROM.

Alesis S4 Plus
Alesis QUADRASYNTH S4 Plus (1994)

S4 Plus Overview

64 polyphonic, 20MB ROM with 48kHz samples.
8MB ROM expansions are available - the Q-Card series.
Using 8MB Flash RAM card, user samples can be loaded with the software called SoundBridge.
A voice is made of 4 layers of simple PCM synth - Alesis calls it QS Composite synthesis.
The filter has no resonance.
Matrix modulation is possible.
"" The Tracking Generator processes modulation signals with a 10-stepped curve.
"" Quadraverb2/MIDIVerb4-based internal multi effects. Five effect algorithms are available that chains and mixes more than 4 FXs.
"" A big LCD display with 4 knobs called Quad Knobs - good interface back in 1994.

Sound Examples

Here are .mp3 sound examples of S4 Plus. The demos are recorded without external effects and overdub. In most examples I used light overdrive to fatten up the sound.

Tracking Generator

Sine (552KB)
Pulse Filter (550KB)
Arpeggiate (807KB)
Spectrum (559KB)

PCM layered

Drums (533KB)
Pluck (449KB)
Bell (490KB)
Organ (470KB)
Saw (548KB)

Programmed with user RAM card samples

Here I used YAMAHA CS10 (processed with ZOOM 9150 Valve DSP FX) and KORG Z1 samples with the optional RAM card.

Z1 guitar model atmosphere (559KB)
CS10 Bass (357KB)
CS10 Resonant pad (628KB)
CS10 Filter FM (394KB)
CS10 PWM distortion (610KB)
CS10 Saw (277KB)

 

Related Models

Alesis QUADRASYNTH is the first synth from Alesis. 64 Polyphony and 16MB ROM were the highest among the synths in those days. Also the big custom LCD and 4 Quad Knobs were impressive.The 1U rackmount version was S4.

Alesis QUADRASYNTH
Alesis QUADRASYNTH (1994)

Later in 1994, Alesis updated them with ROM expansion. The keyboard version QUADRASYNTH Plus had 8MB expansion ROM (24MB total), and S4 Plus had 4MB expansion (20MB total). While QUADRASYNTH Plus had stereo piano samples, S4 Plus had more GM-oriented materials.

With this update, it seems Alesis added anything that ocurred to their mind. There are many small minor changes. Emagic SoundDiver supports S4 Plus, but, regrettably, fails to support important features accurately - especially the extended ROM waves.
One good update is that the stepped curve can now be selected in the Plus version's Tracking Generator. This is useful for making arpeggiator effect.


Two curves of the Tracking Generator

QUADRASYNTH's QS Composite engine is inherited in QS6/7/8/QSR, QS6.1 series, Nanosynth series and the latest QS6.2 series. As to the synth parameters, nothing has changed - 16MB ROM with non-resonant filter.
It could have been much better if the newer QS had Ion's multimode filters - it would make a good, contemporary PCM synthesizer.

Alesis QS6.2
Alesis QS6.2 (2003)

Alesis QUADRAVERB2 multi-effect engine is used in QUADRASYNTHs. Also the drum synth module D4 is related to their drum synth feature.

Alesis QS6.2
Alesis QUADRAVERB2 (1995)

Alesis QS6.2
Alesis D4 (1991)

As synths with non-resonant digital filter, QUADRASYNTH's competitor should be KORG. KORG released many non-resonant PCM synths (M1, M3R, 01/W, AG-10, 03R/W, X5, 05R/W, etc.) from 1988 to 1998, and continued to sell X5D in the new century.

KORG X5
KORG X5 (1993)

The idea of modulation modifier like Tracking Generator may date back to Ensoniq VFX's Modulation Mixer. Kurzweil K2000 has more complex modifier called FUN.
Alesis continued to use Tracking Generator in their newer synths like Andromeda A6, Ion and Micron.

Alesis Andromeda A6
Alesis Andromeda A6 (2000)

 

Links

. Alesis manuals and SoundBridge software available
. The QuadraSynth Pages support site
. Patchman Music S4 Plus .mp3 demo with wind synth sounds




Deep Synthesis: Home

3.5.2007