Instruo Cs-L User Manual

Cš-L

Complex Oscillator

User Manual

Contents

Description / Features

Installation / Speciﬁcations

Overview

Oscillators

Frequency/Pitch

Link Button

Frequency Modulation

Wavefolding

Oscillator Synchronisation

Amplitude Modulation

Internal Modulation Routing

Patch Examples

Description

The Instruō Cš-L is a dual analogue oscillator optimised for generation of complex waveforms. It features two contrasting discrete circuit oscillators that are normalled to one another, offering a variety of simultaneous modulation routings. The resulting harmonic timbres sit far beyond the realms of traditional subtractive synthesis.

It expands upon the classic complex oscillator paradigm prominent in the West Coast synthesis philosophy. Typical cross modulation is expanded upon with inclusion of signal multiplication/amplitude modulation, a wavefolder per oscillator, ﬁnal waveform symmetry biasing, classic and contemporary PWM, a global modulation index bus, and a digitally-controlled routing scheme that can be conﬁgured on-the-ﬂy.

With the two separate oscillator cores, simultaneous access to all included waveforms, and the ability for bi-directional modulation, the

Cš-L truly allows the user to shape sound like never before.

Features

• Two independent contrasting cored analogue oscillators

• Wavefolder per oscillator

• Waveform symmetry biasing

• 1V/Oct linking for parallel tracking

• Four-quadrant signal multiplication/amplitude modulation

• Internal oscillator sync capabilities

• Digitally-controlled internal modulation routing

• Global modulation index bus

• LFO capabilities

• Sub-square modes

Installation

1. Conﬁrm that the Eurorack synthesizer system is powered off.

2. Locate 26 HP of space in your Eurorack synthesizer case.

3. Connect the 10 pin side of the IDC power cable to the 2x5 pin header on the back of the module, conﬁrming that the red stripe on the power cable is connected to -12V.

4. Connect the 16 pin side of the IDC power cable to the 2x8 pin header on your Eurorack power supply, conﬁrming that the red stripe on the power cable is connected to -12V.

5. Mount the Instruō Cš-L in your Eurorack synthesizer case.

6. Power your Eurorack synthesizer system on.

Note:

This module has reverse polarity protection. Inverted installation of the power cable will not damage the module.

Speciﬁcations

• Width: 26 HP

• Depth: 35mm

• +12V: 200mA

• -12V: 80mA

Cš-L | si:-əz-El | proverb (derivative) “complex sauce-later”

Key

1. Osc A 1V/Oct Input

2. Osc A Coarse Frequency

3. Osc A Fine Frequency

4. Osc A Sine Output

5. Osc A Triangle Output

6. Osc A Sawtooth Output

7. Osc A Final Output

8. Mod Button

9. Osc A PWM Output

10. Osc A PWM CV Input 11 . Osc A PWM

12. Osc B 1V/Oct Input

13. Osc B Coarse Frequency

14. Osc B Fine Frequency

15. Osc B Sine Output

16. Osc B Square Output

17. Sub Button

18. Osc B Triangle Output

19. Osc B Final Output

20. Osc B PWM Output

21. Osc B PWM CV Input

22. Osc B PWM

23. Multiply Output

24. Multiply Modulator Input

25. Multiply Carrier Input

26. Depth

27. Ring/AM/Rect Button

Key

28. LFO Button

29. Osc A Lin/Exp Toggle

30. Osc A FM Input

31. Osc A FM Attenuator

32. Osc B Lin/Exp Toggle

33. Osc B FM Input

34. Osc B FM Attenuator

35. Link Button

36. Index Knob

37. Index CV Input

38. Index Attenuverter

39. Index Button

40. Hard Sync Input

41. Soft Sync Input

42. Sync Button

43. Osc A Symmetry Bias Attenuverter

44. Osc A Symmetry Bias Input

45. Osc A Wavefold CV Input

46. Osc A Wavefold Annenuverter

47. Osc A Wavefold Fader

48. Osc B Symmetry Bias Attenuverter

49. Osc B Symmetry Bias Input

50. Osc B Wavefold CV Input

51. Osc B Wavefold Annenuverter

52. Osc B Wavefold Fader

Oscillators

Oscillators A and B share various similarities, but they utilise very different circuitry architectures. Oscillator A features a sawtooth core circuit while Oscillator B features a triangle core circuit. This contrast in cores result in slight variations in the harmonic content of each oscillators’ available waveforms and their strengths and weaknesses. In short, sawtooth core circuits can do certain things better than triangle core circuits, and vice versa. The Cš-L offers the best of both worlds

It is important to note that, because of their different architectures and conﬁgurations, each oscillator has a different global frequency range. This means that matching pointer positions on the Coarse and Fine frequency knobs will not necessarily result in matching output frequencies.

The peak-to-peak amplitude of the various waveform outputs differ from each other slightly. The reference point is 10Vpp on the sawtooth wave. The other signal amplitudes were purposefully chosen to give a more balanced perceived loudness over a musical range. This effect is most prominent between the more harmonically rich waveforms.

Oscillator A (Sawtooth Core)

OSC A PWM

VARIABLE DUTY CYCLE

Sine Output: Sine waveform output.

Triangle Output: Triangle waveform output.

Sawtooth Output: Sawtooth/Ramp waveform output.

Final Output: Final waveform output.

• The waveform is determined by the Wavefold parameter and the

Symmetry Bias Attenuverter.

PWM Output: Pulse width modulation waveform output.

PWM: The PWM knob controls the duty cycle ratio of the

pulse width modulation waveform.

• Turning the knob clockwise will increase the +/– ratio of the pulse wave.

• Turning the knob anticlockwise will decrease the +/– ratio of the pulse wave.

• The range of the PWM knob was chosen to always result in a signal with an audible duty cycle when used without external control voltage.

PWM CV Input: The PWM CV Input is a bipolar control voltage

input for the PWM parameter.

• Control voltage sums with the PWM knob position.

• Input range: -/+5V.

• Note that with external control voltage extending the controllable range of the duty cycle, audibility of the signal will drop when pushed beyond 0% and 100%.

LFO Button: The LFO Button will switch Oscillator A to sub-audio

range frequencies.

If the LFO Button is unilluminated, Oscillator A will output audio range frequencies.

• Oscillator A will continue to track 1V/Octave when set to

LFO Mode.

• The LFO will reset with every rising edge signal present at the Hard

Sync Input of Oscillator A.

If the LFO Button is illuminated white, Oscillator A will output sub-audio range frequencies.

LFO Hard Sync

Oscillator B (Triangle Core)

OSC B PWM

VARIABLE DUTY CYCLE

Final Output: Final waveform output.

• The waveform is determined by the Wavefold parameter and the

Symmetry Bias Attenuverter.

Triangle Output: Triangle waveform output.

Square Output: Square waveform output.

Sub Button: The Sub Button determines the octave of the Square Output.

If the Sub Button is unilluminated, the square waveform is set to the fundamental frequency of Oscillator B.

If the Sub Button is illuminated white, the square waveform is set to one octave below the fundamental frequency of Oscillator B.

If the Sub Button is illuminated amber, the square waveform is set to two octaves below the fundamental frequency of Oscillator B.

Sine Output: Sine waveform output.

PWM Output: Stepped triangle waveform output.

PWM: The PWM knob controls the width of the upper and lower pulses

of the stepped triangle waveform.

• Turning the knob clockwise will increase the width of the upper and lower pulses.

• Turning the knob anticlockwise will decrease the width of the upper and lower pulses.

• The range of the PWM knob was chosen to always result in a signal with an audible duty cycle when used without external control voltage.

PWM CV Input: The PWM CV Input is a bipolar control voltage input

for the PWM parameter.

• Control voltage sums with the PWM knob position.

• Input range: -/+5V.

• Note that with external control voltage extending the controllable range of the duty cycle, audibility of the signal will drop when pushed beyond 0% and 100%.

Frequency/Pitch

Coarse: The Coarse knob controls the fundamental frequency of the

oscillator. It determines the pitch of all corresponding waveforms.

• Turning the knob clockwise will increase the frequency.

• Turning the knob anticlockwise will decrease the frequency.

Fine: The Fine knob is used for minute control of the oscillator’s

fundamental frequency and is relative to the frequency value set by the

Coarse knob. It also determines the pitch of all

corresponding waveforms.

• Turning the knob clockwise will increase the frequency.

• Turning the knob anticlockwise will decrease the frequency.

1V/Oct Input: The 1V/Oct Input is a bipolar control voltage input that

is calibrated to 1V per octave.

• This is traditionally used for frequency control (musical pitch) sent from a sequencer or keyboard.

• Control voltage is added to the summed values set by the Coarse and Fine knobs.

OSC A

OSC B

OSC A

OSC B

Link Button

The Link Button will bidirectionally normal 1V/Octave control voltage signals from one oscillator to the other via either

1V/Oct Input.

If the Link Button is unilluminated, linking is diabled, and the

1V/Oct Input will control the corresponding oscillator only.

If the Link Button is illuminated white, linking is engaged. Sending control voltage to the 1V/Oct Input of Oscillator A only will control both Oscillators A and B. Similarly, sending control voltage to the 1V/Oct Input of Oscillator B only will control both Oscillators B and A.

• If a second 1V/Octave signal is patch in either of the above

conﬁgurations the Link routing normal is broken and the oscillators will track independently.

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Instruo Cs-L User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual