# M4 documentation

The M4 machine consists of four main sections:
the oscillator section,
the amplifier section,
the filter section and
the Low Frequency Oscillator (LFO) section.

#### Oscillator section

You have here two main oscillators (Osc1 and Osc2) and a sub oscillator (SubOsc).
The sub oscillator always oscillates one octave (12 halfnotes) below oscillator 1. Its level you can control with the SubOsc Vol controller.
Oscillator 2 is detuneable with the Osc2 SemiDet and Osc2 FineDet sliders and can be synced by oscillator 1 (Osc2 Sync).
For each oscillator you can choose their wave form with the Wave parameter (Osc1 Wave, Osc2 Wave and SubOsc Wave).
The pulse width controllers (Osc1 PW and Osc2 PW) move the centers of the waves to left/right. Below you see a sine wave with pulse width 50:50 and with pulse width about 70:30. Hope you understand the principle.

With the Osc Mix slider you control the balance between oscillator 1 and oscillator 2. The Osc MixType fader is for controlling the kind of mixture.
The oscillator section contains a Pitch Envelope. The attack and decay time can be adjusted with the Pitch Attack and Pitch Decay faders, the strength of the envelope modulation with Pitch EnvMod. Negative envelope modulation is also possible.
With the Pitch Glide slider you control the speed of portamento. A value of 0 means no portamento, 127 is a very slow glide effect.

#### Amplifier section

The amplifier has a linear Attack-Sustain-Release envelope curve. The Amp Attack, Amp Sustain and Amp Release faders control the attack, sustain and release time of the amplitude enevelope. The volume (sustain level) is a non global parameter and is controlled per track.

#### Filter section

In the filter section you have lowpass filter with -12db, -18db and -24db/octave and highpass filter with resonance adjustment and bandpass/bandreject(notch) filter with bandwidth controlling.
Choose one of them with Filter Type. The cutoff/center frequency you control with the Filter Cutoff slider, the resonance or bandwidth with Filter Q/BW (Q=Quality=Resonance, BW=BandWidth).
The filter has an envelope for the cutoff/center frequency. Set the attack, sustsain and release time with Filter Attack, Filter Sustain and Filter Release, the strength of modulation with Filter EnvMod. Negative envelopes are possible.

#### Low Frequency Oscillator section

The M4 machine has two low frequency oscillators (LFO1 and LFO2).
A LFO is a very slow oscillator which can modulate different parameters of the oscillators, amplifier and filter.
LFO1 Dest and LFO2 Dest (Dest = Destination) specify, which parameter(s) the LFOs modulate.
LFO1 can modulate the frequency of oscillator 1, the pulse width of oscillator 1, the volume and the filter cutoff/center frequency.
LFO2 can modulate the frequency of oscillator 2, the pulse width of oscillator 2, the oscillator mix and the filter resonance/bandwidth.
LFO1 Wave and LFO2 Wave specify the waveform of the LFOs. If random is selected, the LFO holds one random value for the time of one cycle (sample and hold).
With LFO1 Freq and LFO2 Freq you set their frequencies in Hertz (0-116) or in Ticks (117-127).
The strenght of the modulation of the selected parameters by the LFOs you set with the LFO1 Amount and LFO2 Amount sliders.
In the Attributes window you can scale the amounts for the different parameters. from 0% (0) to 100% (127).

With this feature you can for example modulate the pulse width of oscillator 1 only very slightly (LFO1 PulseWidth1 Scale = 13 (about 10%)) and the filter cutoff frequency very strong (LFO1 Cutoff Scale = 127 (100%)) with the same LFO.
With the LFO1 Ph Diff and LFO2 Ph Diff you can get very nice sounding results. Ph Diff means Phase Difference, so what these parameters do is setting different LFO phases for every track.
Below you see a picture of a sine LFO wave for three tracks with a phase difference of 90°, which means 90° difference between track 0 and 1, 90° difference between track 1 and 2. If this LFO modulates the cutoff frequency for example, you have different cutoff frequencies for each track. Hope you understand.

I've spend really much time to write this doc, so I hope it helps you.
happy sounding!

Makk (makk@gmx.de)