background image

There are two different sustain modes, depending on the

position of this toggle switch.

Down position

 - In this mode the footswitch will hold the

note forever (basically bypassing the guitar input), until

pressed again.

Up position

 - In this mode the footswitch will enable

guitar signal triggered sustain. When the threshold LED

turns off, as the signal falls below the threshold, it will hold

the current note.

Sustain

2/2

18.

The SW MODE switch

For the guitar triggered sustain mode to work the Threshold

needs to be set up correctly- see page 15.

Summary of Contents for Multiwave Mega

Page 1: ...MULTIWAVE MEGA user manual v1 0 ...

Page 2: ...www parasitstudio se The Multiwave Mega guitar synthesizer Supply 9V DC negative center Current draw 56mA ...

Page 3: ...4 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Index Introduction Buttons overview Button 1 Button 2 Button 3 Button 4 Knobs overview Threshold Sustain footswitch Sustain SW MODE switch Tips Quirks and Bugs Technobabble Tiny oscilloscope Credits ...

Page 4: ...ter with envelopes Sustain mode aka drone mode LFO s for both the oscillators and filter OLED oscilloscope only avaliable on the fully assembled version KEY FEATURES The two oscillators will be reffered to here as the primary and the secondary oscillator When first powering up you will only hear the primary oscillator by default The secondary oscillator needs to be activated using the Blend functi...

Page 5: ... 500ms Shift press press and hold button 1 marked Shift then press one of the other buttons The LED will blink two times to indicate a long press and it will blink 3 times fast when doing a shift press This gives a nice visual indication of the button response 3 The row under the button describe the Shift press functions The top row describe the normal press functions the second row describe the l...

Page 6: ...tor 1 Sawtooth 2 Square 3 Pulse 4 Narrow pulse 5 Bell 6 Sine 7 Noise The Bell waveshape is an FM inspired shape that blends sinewaves at different frequencies to produce a bell like sound The noise is technically still a sinewave but it starts from a random postition within the wavetable to produce noise ...

Page 7: ...secondary oscillator See the Blend details on button 2 page 6 SELECT long press Press and hold this button then press one of the other buttons to activate their respective shift functions Shift functions are described under the buttons on the same row as the Shift marking SHIFT ...

Page 8: ...st step is just slightly detuned followed by 5 other musical intervals Note that only the primary oscillator will detune so when the blend is activated this will create a layered sounds between the two oscillators almost like playing chords The first detune setting is just slightly out of tune so it will create a cool phasey modulating sound ...

Page 9: ...tor can be selected by doing a long press of button 1 This way you can blend any of the waveshapes together using button 1 toggle select except the noise waveshape 7 that can only be used with the primary oscillator OCTAVE shift press This will transpose the secondary oscillator down one octave so it can basically become a sub oscillator to fatten up the tone ...

Page 10: ...d by doing a long press this will toggle through three different envelope shapes used to sweep the filter cutoff 1 fast attack slow release 2 slow attack slow release 3 slow attack fast release If the VCF isn t activated normal presses to this button does nothing ...

Page 11: ...vated the filter is insted controlled by an envelope that will sweep the filter cutoff automatically just like having an invisible robot turn the filter cutoff knob for you when hitting a note This envelope is triggered by the guitar input by default For this to work the threshold needs to be adjusted to suit the guitar signal strenght See page 15 on the threshold control ...

Page 12: ...n it will go through the attack portion of the envelope the filter will open up and hold it open until the signal has dropped below the threshold and the LED turns off again then it will go through the release portion of the envelope In VCF mode the filter cutoff knob now acts as a rate knob insted It now controls how fast it goes through the envelope From slow sweeps to fast wah ish sounds ...

Page 13: ...al basically turning it into an LFO Low Frequency Oscillator The rate is controlled by the cutoff rate knob and the same selection of envelope shapes can still be toggled through with normal button presses The filter envelope LFO and the main LFO are totally independent so both can be running simulaniously with different rates and shapes ...

Page 14: ...ugh 4 different waveshapes for the LFO 1 Sinewave 2 Sawtooth 3 Ramp inverted saw 4 Pseudo random When the LFO is off normal presses to this button does nothing Note that the random shape sounds alot faster than the other LFO shapes so turn down the rate when using it or max the rate to use it as a noise creator ...

Page 15: ...has two modes In both modes it will respond very differently depending on the oscillator waveshape For example for square waves it will do a clean amplitude volume modulation like a tremolo But if the oscillator is running a sawtooth it will modulate the amplitude but also the waveshape and frequency as the amplitude goes up and down this is most noticable at low LFO rates ...

Page 16: ...FO to an alternative mode that does a more intense and harsher sounding frequency modulation with less amplitude modulation One of my favourite settings is using this LFO mode together with the random wavshape which will create what sounds like a random note sequencer ...

Page 17: ...e overall output volume RESO control the amout of filter resonance CUTOFF controls the filter cutoff frequency RATE controls the speed of the LFO In VCF mode the cutoff knob insted becomes a rate control for the envelope filter LFO ...

Page 18: ...off as soon as the note starts to decay Tip Turn the pot fully clockwise the LED will turn on and then turn it slowly counter clockwise until the LED goes off Just around this point there s a small sweetspot that will trigger the envelope sustain mode just the right way Note that the guitar output may be very low when playing on the highest notes thus not triggering the threshold at all This is no...

Page 19: ...ootswitch The Multiwave Mega has a sample and hold feature that will sustain a note forever aka drone Mode This is enabled with the Sustain footswitch When the sustain mode is enabled the LED next to the toggle switch will turn on ...

Page 20: ...ypassing the guitar input until pressed again Up position In this mode the footswitch will enable guitar signal triggered sustain When the threshold LED turns off as the signal falls below the threshold it will hold the current note Sustain 2 2 18 The SW MODE switch For the guitar triggered sustain mode to work the Threshold needs to be set up correctly see page 15 ...

Page 21: ...rolled all the way down This will improve tracking greatly You can also try palm muting notes especially when playing low notes to improve the tracking Sustain mode Adjusting the playstyle is even more important when using the guitar triggered sustain mode I find that I get the best results when letting notes sustain as much as possible insted of playing choppy since it will sample and hold no mat...

Page 22: ...is is normal behaviour When the noise is selected it demands alot of processing power from the microcontroller so it s best used without the blend activated Just note that the filter has a bit of stepping to it especially at the bottom of the range which gets pronounced with the resonance turned up The Sample Hold is analog so after a while it will start to drift alittle out of tune It uses a capa...

Page 23: ... This is needed so that the microcontroller doesn t have to do anything too demanding using timers It simply uses an external interrupt to cycle through the waveshape arrays The oscillators are wavetable based which means that every waveshape is stored as an array of numbers that represents pwm duty cycle voltage levels for a single waveshape cycle It has a 6 bit resolution 64 steps for the oscill...

Page 24: ...scilloscope that gives a nice visual feedback The OLED and the related circuitry is not included or supported with the PCB DIY kit since it would make it harder to for people to build having to make a square hole and add an extra cost The scope is nice to have but not necessary All the other features are the same ...

Page 25: ... s been a great learning experience especially since programming is not my strong suite so I had to learn alot as I went along When the third prototype PCB arrived after a long wait and had several issues I was almost ready to give up and scrap the whole project But I kept going at it patience young padawan and finally had a working final version worthy of a release In the end I think that it turn...

Page 26: ...www parasitstudio se ...

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