Analogue Systems


RS-370

Polyphonic Harmonic Generator

The mighty RS-370 Polyphonic Harmonic Generator can be used as a digital 6-voice additive polyphonic synthesizer and/or as a six-voice polyphonic MIDI/CV/Gate interface.


The RS-370 v3 - which can be differentiated from its predecessor by the second line of annotation under the bottom row of sockets (START, STOP, START/STOP... and so on) is an updated version of the original RS-370, with more facilities, a full implementation of wavetable synthesis, and an improved selection of factory sounds. The principles of its operation are identical to those of the original RS-370, but the menu structure is significantly enhanced, so this chapter describes its operation in full, rather than attempting to 'bolt on' the new menus and commands to the information contained in the previous chapter.

Note: All versions of the RS-370 can be upgraded to v3.x capabilities by a simple firmware update

ABOUT WAVETABLE SYNTHESIS

Imagine creating dozens of similar waveforms and placing them in some sort of order in digital memory. Now imagine that you can tell a sound generator to use any one of these waveforms as the basis of a sound, or even to sweep backward and forward through the memory, using one waveform for a fraction of a second, and then the next, and then the next...

The memory that contains the waves is called a "wavetable", and when you create sounds by sweeping through the table, the result is called "wavetable synthesis". This has existed since the late 1970s, and reached its zenith in the mid-80s in the form of the PPG2.2, a synthesiser that delivered a whole new palette of brittle and glassy sounds that had never been heard before. By adding fifteen new wavetables and menu 2.1.10 (Morph table) to the RS-370, it has become a true wavetable synthesizer as well as an additive synthesizer, and is now capable of a huge range of PPG-esque sounds, and many more besides.

Even if you have already owned and used an earlier version of this module, perhaps obtaining this version as a firmware upgrade, you should investigate the new capabilities thoroughly. The enhanced RS-370 is a completely new synthesizer!

In use :

INTRODUCTION TO THE RS-370 FAMILY

The RS-370 is a self-contained digital synthesizer that runs on a TMS320VC5412 digital signal processor. It offers multiple modes of operation and can connect in a variety of ways with your analogue synthesizers and MIDI-equipped systems. It is also a powerful MIDI to CV converter that you can use independently of the internal sound generator.

To make sense of the RS-370, let's start by looking at the sound generator itself:

  • it is 6-note polyphonic
  • it incorporates no fewer than 24 digital oscillators, so each note (or 'voice') comprises up to four oscillators (although each uses the same waveform)
  • it offers a range of common waveforms, but you can create a huge number of new waves using additive (also called 'Fourier' or 'harmonic') synthesis
  • each additive oscillator comprises 32 harmonics
  • each of the four oscillators in a voice can be independently detuned... which means that a note can contain up to 128 independent 'partials'

Many additional features help you to obtain the most from the sound generator. These include:

  • independent audio amplifiers and outputs for each voice
  • independent 6-stage EGs for each voice, internally routed to the audio amplifiers
  • 'vintage drift' to emulate the tuning instabilities and warmth of analogue synthesisers
  • dual LFOs
  • a multi-mode arpeggiator
  • forty-six patch memories

You can control all of this using analogue CVs and MIDI controllers. Furthermore, you can use the CTRL outs to control external modules and synthesisers as well as the internal sound generator.

Facilities include:

  • MIDI In and Thru (with activity LED)
  • six pitch CV outputs
  • six Trigger outputs that you can configure as triggers, gates, or S-Trig outputs
  • three CV inputs that you can direct to a variety of internal destinations
  • four MIDI/CV CTRL outs that respond individually to over 130 MIDI controllers

To all of the above, the RS-375 Expander adds:

  • sixteen control knobs linked to sixteen CV inputs, which together allow you to adjust the envelopes and control the amplitudes of the first sixteen harmonics of additive sounds in real-time
  • four additional CV inputs
  • four additional CTRL outputs

Alternatively, the RS-376 Expander adds:

  • four additional CV inputs
  • four additional CTRL outputs
  • a single control knob

 GETTING STARTED

You should hook up your RS-370 so that you can obtain sound from it before you begin to experiment with the commands and controls described in this chapter. Follow the instructions below. This will help you to obtain a full grasp of the module as you work through the menus.

  1. Read the "Introduction to the RS-370 family" in the previous chapter, and as well as the general description of the module.
  2. Read the section "Navigating the RS-370" so that you know how to follow these instructions.
  3. Connect a MIDI cable from the MIDI output of a controller keyboard to the MIDI In of the RS-370.
  4. Ensure that the MIDI Transmit channel of the keyboard is the same as the MIDI Receive channel of the RS-370. (Menu 7.3.)
  5. Connect the "VOICE 1" output to the input of a receiving device such as a mixer or the input to an audio amplifier.
  6. Check that all six voices are being sent to the VOICE1 output by selecting "All outputs mixed" in menu 2.1.6 - Synthesizer/Voice outputs/Output mixing.
  7. Select menu 1 (Copy from memory) and choose any of the patches that takes your fancy.
  8. Play. If no sound is produced, check that the MIDI activity LED flashes as you the press keys on the MIDI keyboard, and that all the connections are correct.
  9. Play. If you still have no output, ensure that you have not sent a MIDI CC#7 (Volume) = 0 to the RS-370. This will silence the module, even if all other settings appear correct.
  10. Play again.When used in this way, the RS-370 acts like any other 6-voice polyphonic synthesiser, generating and shaping up to six notes simultaneously.

Note: Some of the factory patches are monophonic, so do not panic if your RS-370 appears only to produce a single note. Select an alternative patch, and all should be well

MODES

Before starting, it's important to understand that the RS-370 offers four modes of operation, and that the menu structure may differ slightly depending on which mode is selected.

You can split the modes into two groups: polyphonic, and real-time:

  • The two polyphonic modes allow you to play all six voices simultaneously, but neither allows you to modify the harmonic content of additive waveforms while playing.
  • The two real-time modes allow you to modify the harmonic content of additive waveforms in real-time (hence the name) but you are restricted to just a single voice, thus transforming the RS-370 into a monophonic synthesizer.

THE MODES ARE:

Polyphonic MIDI

  • Polyphonic: The RS-370 acts as a 6-voice polyphonic sound generator.
  • MIDI: The RS-370 also acts as a 6-channel MIDI/CV converter. The sockets marked CV1 to CV6 and TRIGGER1 to TRIGGER6 therefore become MIDI/CV outputs.

Polyphonic analogue

  • Polyphonic: The RS-370 acts as a 6-voice polyphonic sound generator.
  • Analogue: The sockets marked CV1 to CV6 and TRIGGER1 to TRIGGER6 become analogue inputs.

MIDI real-time

  • Real-time: The RS-370 acts as a monophonic harmonic synthesiser with one voice comprising four oscillators. You can modulate the harmonic levels of a sound in real-time, immediately hearing the effect on the sound.
  • MIDI: The RS-370 also acts as a 6-channel MIDI/CV converter. The sockets marked CV1 to CV6 and TRIGGER1 to TRIGGER6 therefore become MIDI/CV outputs.

Note: This mode is useful only when used in conjunction with the RS-375 Expander.

Analogue real-time

  • Real-time: The RS-370 acts as a monophonic harmonic synthesiser with one voice comprising four oscillators. You can adjust the harmonic levels of a sound in real-time, immediately hearing the effect on the sound.
  • Analogue: The CV 1 socket becomes a dedicated 1V/Oct pitch control input.

Note: This mode is useful only when used in conjunction with the RS-375 Expander.

NAVIGATING THE RS-370

The RS-370 is controlled by the menus displayed on its graphic LCD.This display is backlit to aid its use in darkened conditions.

  • Navigate through the menu structure by rotating the EDIT knob.
  • Select a menu by pressing the EDIT knob.
  • Navigate through any menu by rotating the EDIT knob.
  • Move "down" to select a sub-menu or list of options by pressing the EDIT knob.
  • Alter a value by rotating the EDIT knob.
  • Save a change (and, where appropriate, return to the previous level) by pressing the EDIT knob.
  • Jump "up" a level by pressing CANCEL.
  • Leave an option or parameter unchanged and return to the menu containing it by pressing CANCEL.

Menu numbering

The menu hierarchy of the RS-370 is quite extensive, so we rationalise it by thinking in terms of a major heading, followed by sub-menus, sub-sub-menus, and so on. When you press one of the options in the start-up screen, you will enter one of the menus as follows:

Menu 1: Copy from memory

Menu 2: Synthesiser

Menu 3: LFO

Menu 4: Arpeggiator

Menu 5: Memories

Menu 6: MIDI/CV conversion

Menu 7: MIDI options

Menu 8: Special options

In most cases you will now have the option to select further sub-menus that we refer to as "menu x.x". For example, if you press EDIT to enter the "Synthesiser" menu, and then press EDIT again to select the "Voice outputs" sub-menu (which is the first item in the list), you enter menu 2.1. This in turn offers sub-sub menus, which are numbered 2.1.1... and so on.

A bit of advice...The RS-370 is a powerful module, so you may find it a little daunting at first. Nonetheless, it is remarkably simple to use once you have come to grips with the menu structures. Experiment freely, as this is the best way to learn the system. If you need help, please email Analogue Systems for support.

Audio Files :

Below are six tracks which showcase the capabilities of the Analogue Systems RS-370 Polyphonic Harmonic Generator. These soundscapes were created by Bakis Sirros of Parallel Worlds. All were done in real time with no multitracking. 

Agony

Dominated

Dominated 2

Symphony Of Metals

Running Out Of Time

Running Out Of Time 2

Analogue Systems

Custom vintage analogue synthesiser system equipment.