Moog SYSTEM 15 - User Manual

Instruction Manual
for
MOOG Synthesizer
System 15
• Introduction
• Module Functions
• Initial Setup
• Basic Definitions
• Instructional Sequences

Summary

Introduction

Module Functions

Initial Setup

Basic Definitions

Instructional Sequences

The Audio Generators

Demonstrates basic sound generation using oscillators and noise sources to explore raw audio signals.

Using the Keyboard to Determine Pitch

Explains how to control the pitch of synthesized sounds using the keyboard controller and associated modules.

Using the Keyboard to Articulate the Sound

Details how to shape the temporal dynamics (envelope) of sounds using the envelope generator and keyboard.

Using Both 921 B Oscillators and the 921 Voltage Controlled Oscillator

Illustrates combining multiple oscillators, including a VCO, to create complex multi-voice tones.

Filters

Covers the application of various filter modules (Fixed, Voltage Controlled Lowpass) for tone color and spectral shaping.

Use of Two Envelope Generators and the Reversible Attenuator

Demonstrates advanced modulation techniques using multiple envelope generators and a reversible attenuator.

The 921 Voltage Controlled Oscillator

Provides a detailed explanation of the 921 Voltage Controlled Oscillator's waveforms, controls, and operation.

The 921 Voltage Controlled Oscillator Clamping Point

Explains the 'clamping' functionality of the 921 VCO, which abruptly sets waveform points via trigger signals.

Synchronization of Oscillators

Describes methods for synchronizing oscillator outputs to create harmonically related or sub-harmonic relationships.

Modulation of the Oscillator Bank

Explores frequency modulation techniques applied to the oscillator bank using control signals for dynamic pitch changes.

995 Attenuators Panel

Details the functionality of the 995 Attenuators Panel for reducing signal magnitudes and creating multiple attenuation levels.

Overview

1. Function Description
2. Usage Features
3. Maintenance Features

The Moog Synthesizer System 15 is a professional modular electronic music instrument designed for both live performance and studio use. Its compact size and convenient layout make it suitable for various musical applications, offering a wide range of sounds and effects. The system is built with high-quality, precisely-engineered components, ensuring reliability and versatility.

Function Description:

The Synthesizer System 15 comprises several modules, each with specific functions that contribute to sound generation, modification, and control.

• 921A Oscillator Driver: This module allows a single set of control voltages to determine the pitch and rectangular waveform widths of the 921B Oscillators. It acts as a central control point for multiple oscillators, ensuring consistent pitch relationships.

• 921B Oscillator: These are the primary sound sources, producing basic waveforms (sine, sawtooth, triangle, and rectangular) for both audio and control purposes. They feature expanded facilities for modulation and synchronization, allowing for complex sound textures and rhythmic interactions.

• 921 Oscillator: Similar to the 921B, this module also produces basic repetitive waveforms for audio and control. It includes expanded facilities for triggered waveform clamping and waveform level variation, offering additional control over the initial attack and overall dynamics of a sound.

• 923 Filters / Noise Source: This module combines filtering capabilities with a noise generator.

  • Lowpass Filter: Attenuates frequencies above a set cutoff point, allowing lower frequencies to pass through.
  • Highpass Filter: Attenuates frequencies below a set cutoff point, allowing higher frequencies to pass through.
  • Noise Source: Generates both white noise (containing all audible frequencies in a random mixture) and pink noise (with more low-frequency and less high-frequency content than white noise), useful for percussive sounds, atmospheric effects, or as a modulation source.

• 902 Voltage Controlled Amplifier (VCA): This module shapes the amplitude (loudness) of a signal in response to control signals. It is crucial for articulating sounds, creating dynamic changes, and implementing envelopes.

• 904A Voltage Controlled Lowpass Filter: This is a more advanced lowpass filter where the cutoff frequency can be controlled by external voltage signals. It also features a "Regeneration" control, which emphasizes frequencies around the cutoff point, leading to resonant effects.

• 907 Fixed Filter Bank: This module divides the audio spectrum into ten separate bands, each with an individual attenuator. Eight bands cover approximately half-octave frequency ranges, while two additional sections handle the lowest (20-200 Hz) and highest (3,500-20,000 Hz) audible frequencies. This allows for precise spectral shaping and equalization.

• 911 Envelope Generator: This module produces transient control contours (envelopes) whenever it receives a trigger signal. These envelopes typically control the amplitude of a VCA or the cutoff frequency of a filter, shaping the attack, decay, sustain, and release phases of a sound.

• 952 Keyboard Controller: This module generates two independent control voltages (for pitch) and two independent trigger signals (for initiating envelopes) in response to depressed keys. It allows for melodic and harmonic playing, with controls for scaling intervals and transposing pitch.

• 995 Attenuators: This panel allows for the reduction of the amplitude of up to three signals. Its hierarchical input arrangement enables a single signal to be attenuated in multiple ways or routed to different destinations with varying levels.

• Mixer Panel: This module combines multiple audio or control signals into two complementary outputs, allowing for the blending of different sound sources or modulation signals.

• Reversible Attenuator: This module permits any signal to be reversed in polarity and varied in magnitude, offering creative possibilities for modulation and signal processing.

Usage Features:

The Moog Synthesizer System 15 is designed for hands-on exploration and experimentation. Users are encouraged to listen carefully and critically to understand the impact of each control.

• Modular Patching: Signals are routed between modules using patch cords (1/4" phone plugs) and trigger cables (two-prong connectors). Patch cords are color-coded by length for easy identification.
  • Patching Rules: Outputs connect to inputs. A "MULTIPLE" can split a signal to multiple inputs. A "MIXER" combines outputs. Control signals generally do not patch into audio signal paths, but audio signals can be used as control signals. Specific modules (902 VCA, 923 Lowpass Filter, Mixer Panel, Reversible Attenuator) can process slowly-varying control signals.
• Keyboard Control: The keyboard controller provides pitch control and trigger signals. The "SCALE" control adjusts interval size, and "RANGE" transposes pitch. The "GLIDE" control introduces a portamento effect, slowing down pitch changes.
• Envelope Shaping: The 911 Envelope Generator allows users to sculpt the loudness-time contour of sounds. Controls for T1 (Rise Time), T2 (Initial Decay Time), Esus (Sustain Level), and T3 (Final Decay Time) provide detailed control over the sound's articulation.
• Oscillator Modulation and Synchronization:
  • Frequency Modulation: Control signals can be applied to oscillator frequency inputs to create vibrato, siren effects, or complex timbral changes. The 921A offers exponential control (constant musical interval change), while 921B's AC/DC MODULATE inputs offer linear control (constant frequency difference).
  • Waveform Width Modulation: The width of rectangular waveforms can be modulated, altering the tone color.
  • Synchronization: Oscillators can be synchronized to external signals, creating harmonically related tones and eliminating beats. Sawtooth waveforms are used for whole-number multiples (overtones), and sine waves for submultiples (sub-harmonics). The "SYNCH" switch offers "STRONG" (for stable synchronization) and "WEAK" (for higher waveform purity) positions.
• Filtering: Various filters (907 Fixed Filter Bank, 904A Voltage Controlled Lowpass Filter, 923 Filters) allow for extensive tonal shaping, from basic equalization to resonant sweeps.
• Clamping Point: The 921 Voltage Controlled Oscillator's "Clamping Point" section allows the waveform to abruptly reset to a selected point in its cycle upon receiving a trigger signal, useful for creating unique attack characteristics.
• Signal Attenuation: The 995 Attenuators and Reversible Attenuator provide precise control over signal levels and polarity, essential for mixing and complex modulation setups.

Maintenance Features:

• Initial Setup: The manual provides clear instructions for setting up the synthesizer, including placement, connecting the keyboard controller, and powering the unit. It also addresses potential issues like line voltage fluctuations and recommends using a voltage regulating transformer if needed.
• Audio Output Connection: Instructions are given for connecting the synthesizer to a sound system or tape recorder, specifying nominal audio output levels and impedance.
• Warranty Registration: Users are reminded to fill out and send in the Warranty Registration card.
• Modular Design: The system's modular nature implies that individual modules can be replaced or serviced, contributing to its long-term maintainability.
• No Technical Training Needed: The manual emphasizes that no technical training is required to operate the synthesizer, suggesting a user-friendly design and accessible troubleshooting for common issues. A good musical ear and basic physical terms knowledge are sufficient.

Moog SYSTEM 15 Specifications