Sequential Circuits Fugue

KEYBOARD 49 keys with no velocity, main panel features 44 levers and 6 buttons - on the left part a pitch bender joystick with a control slider for portamento level.

RELATED MODELS:
- Siel CRUISE different outfit, the same
- Sequential Circuits prelude is another SIEL rebrand for ORCHESTRA 2

Terminal connectors:

- main audio out

- monophonic section separate out

- polyphonic separate out

- 5 dins input for volume swell pedal

- sustain footswitch for piano part

- decay footswitch for polyphonic section

OSCILLATORS The Fugue keyboard sound generation is fully analog and split into 2 main sections:

A- monophonic: partially derived from mono synthesizer based on M110B1 SGS IC

B- polyphonic: PWG - Polyphonic Waveforms Generator based on TDA 100

EFFECT a single effect ANIMATION based on TDA 1022 - according to the original advertising this effect was aimed to recreate acoustic reverberation of a hall concert type, but it sounds more like an analog chorus

Basically the the oscillator DCO is pretty simple with just sawtooth / square shape + an octave setting at 4' 8' 16' 32. This section is partially derived from SIEL MONO Features same 10 presets sounds when set in edit mode (called mode "FREE") it is possible to access direct DCO edit

PRESETS: basso tuba, piccolo, trombone, sax, trumpet, flute, violin, guitar, bass and clarinet

LFO a single triangular modulator with variable rate /depth and 2 destinations: LFO to DCO Pitch / LFO to VCF filter

ENVELOPE a single EG type 4 segments ADSR

FILTER: Section is slimmed-down from original MONO synthesizer: VCF is no more multi mode but only lowpass controlled by 2 sliders for cutoff and resonance up to self-oscillation. The KTF is a simple key tracker for more brilliance on higher octaves.

Up to 49 voices polyphony based on PWG - Polyphonic Waveforms Generator - with 12 X TDA 1008 - 16 pins frequency dividers. The are 4 PWG presets families with minor edit parameters:

BRASS Instruments: trombone and trumpet

Controls: filter cutoff-resonance plus a 2-stages EG attack + crescendo.

STRINGS: Instruments: violin, cello and percussion

Controls: EG control over attack and decay- this control is shared between reed and piano family

REED Instruments: accordion, musette, church organ

Controls: 1 EG control for attack segment

PIANO Instruments: piano, clavinet, honkytonk

Controls: variable decay

Sequential Circuits Fugue

Mono and Polysynthesizer (1982)

Overview

Sound

Mono section in depth

Polyphonic Section