[{"data":1,"prerenderedAt":595},["ShallowReactive",2],{"page:\u002Flearn\u002Ffm-and-distortion":3},{"id":4,"title":5,"article":6,"body":7,"description":587,"extension":588,"meta":589,"navigation":6,"path":590,"seo":591,"seoTitle":592,"stem":593,"__hash__":594},"pages\u002Flearn\u002Ffm-and-distortion.md","FM & distortion: changing the timbre",true,{"type":8,"value":9,"toc":573},"minimark",[10,14,34,39,47,63,67,88,91,111,117,281,286,304,313,317,329,353,360,404,408,416,433,464,468,484,521,525,528,532],[11,12,5],"h1",{"id":13},"fm-distortion-changing-the-timbre",[15,16,17,18,23,24,28,29,33],"p",{},"The ",[19,20,22],"a",{"href":21},"\u002Flearn\u002Ffilters","filters guide"," was all about ",[25,26,27],"em",{},"taking away",": start with a bright sound and carve it darker. This guide goes the other way. Every technique here ",[30,31,32],"strong",{},"adds"," new harmonics that weren't in the sound before, which is how you get bells, metallic clangs, growls, fuzz and digital grit from plain old waves.",[35,36,38],"h2",{"id":37},"modulation-but-fast","Modulation, but fast",[15,40,41,42,46],{},"In the ",[19,43,45],{"href":44},"\u002Flearn\u002Fmodulation","modulation guide",", an LFO moved a knob a few times a second, and you heard it as movement: a sweep, a wobble, vibrato. So what happens if the modulation gets faster? Ten times a second, a hundred, a thousand?",[15,48,49,50,53,54,57,58,62],{},"Somewhere around 20–30 times a second, your ear stops hearing ",[25,51,52],{},"movement"," and starts hearing a new ",[25,55,56],{},"tone",". The wobble is too fast to follow, so it blends into the sound itself and becomes part of its colour. That's ",[19,59,61],{"href":60},"\u002Flearn\u002Fglossary#audio-rate","audio-rate"," modulation, and it's one of the most powerful ideas in synthesis.",[35,64,66],{"id":65},"fm-one-oscillator-bending-another","FM: one oscillator bending another",[15,68,69,72,73,76,77,80,81,84,85,87],{},[30,70,71],{},"FM"," (frequency modulation) means using one oscillator to wiggle the pitch of another, very fast. The one you hear is the ",[30,74,75],{},"carrier",". The one doing the wiggling is the ",[30,78,79],{},"modulator",". Neither is special: they're both ordinary VCOs, patched modulator ",[30,82,83],{},"OUT"," → carrier ",[30,86,71],{},".",[15,89,90],{},"Two knobs matter most:",[92,93,94,105],"ul",{},[95,96,97,100,101,104],"li",{},[30,98,99],{},"How hard",": the carrier's ",[30,102,103],{},"FM Amt",". A little gives a gentle sheen; a lot gives a bright, complex tone full of new harmonics.",[95,106,107,110],{},[30,108,109],{},"The ratio"," between the two pitches. When the modulator sits at a simple multiple of the carrier (the same note, an octave up, two octaves up), the new harmonics line up musically and you get clear, bell-like and electric-piano tones. Knock the ratio slightly off and the harmonics stop lining up: clangy, metallic, inharmonic sounds, like gongs and hit metal.",[15,112,113,114,116],{},"And here's the trick that makes FM sound alive: put a VCA and envelope on the ",[25,115,79],{},". Then the FM amount changes over each note, so the sound starts bright and complex and mellows as it rings, exactly like a struck bell.",[118,119,123,132,242,245],"try-it",{"lesson":120,"title":121,":unpatched":122},"12-fm-audio-rate-modulation","Make a bell","true",[15,124,125,126,128,129,131],{},"Two sine VCOs, two VCAs and an envelope, with no cables. The left VCO is the ",[30,127,79],{},", set an octave up; the right one is the ",[30,130,75],{},", the one you'll hear. Build a plain voice first, then bend it:",[133,134,135,168,211,231],"ol",{},[95,136,137,138,140,141,143,144,147,148,150,151,154,155,160,161,160,165],{},"Patch the right VCO's ",[30,139,83],{}," into the VCA under the ADSR, that VCA's ",[30,142,83],{}," into the Output's ",[30,145,146],{},"MONO",", and the same ",[30,149,83],{}," into the Scope's ",[30,152,153],{},"A"," so you can watch the wave. ",[156,157],"wire",{"from":158,"to":159},"vco#car.out","vca#vca.in"," ",[156,162],{"from":163,"to":164},"vca#vca.out","out.in",[156,166],{"from":163,"to":167},"scope.a",[95,169,170,171,174,175,177,178,181,182,184,185,187,188,191,192,195,196,160,200,160,203,160,207],{},"Patch the Keyboard's ",[30,172,173],{},"V\u002FOCT"," into the ",[30,176,173],{}," of both VCOs, its ",[30,179,180],{},"GATE"," into the ADSR's ",[30,183,180],{},", and the ADSR's ",[30,186,83],{}," into that VCA's ",[30,189,190],{},"CV",". Play ",[30,193,194],{},"A–K",": a plain, soft sine. ",[156,197],{"from":198,"to":199},"keys.pitch","vco#car.pitch",[156,201],{"from":198,"to":202},"vco#mod.pitch",[156,204],{"from":205,"to":206},"keys.gate","adsr.gate",[156,208],{"from":209,"to":210},"adsr.out","vca#vca.cv",[95,212,213,214,216,217,219,220,222,223,160,227],{},"Now the left VCO: patch its ",[30,215,83],{}," into the VCA under it, and that VCA's ",[30,218,83],{}," into the right VCO's ",[30,221,71],{},". Still plain: that VCA is shut. ",[156,224],{"from":225,"to":226},"vco#mod.out","vca#mvca.in",[156,228],{"from":229,"to":230},"vca#mvca.out","vco#car.fm",[95,232,233,234,174,236,238,239],{},"Patch the ADSR's ",[30,235,83],{},[30,237,190],{}," of the VCA under the left VCO too. Play: a bell. Each note starts bright and mellows as the envelope closes the FM. ",[156,240],{"from":209,"to":241},"vca#mvca.cv",[15,243,244],{},"Then play with it:",[92,246,247,260,271],{},[95,248,249,250,253,254],{},"Set the left VCO's ",[30,251,252],{},"Oct"," to +2 for a brighter, glassier bell. ",[255,256],"knob",{"module":257,"param":258,"above":259},"vco#mod","oct","1.5",[95,261,262,263,266,267],{},"Nudge the left VCO's ",[30,264,265],{},"Fine",": clangy, inharmonic metal. ",[268,269],"turn",{"module":257,"param":270},"fine",[95,272,273,274,276,277],{},"Turn the right VCO's ",[30,275,103],{}," up and down to hear how much brightness it adds. ",[268,278],{"module":279,"param":280},"vco#car","fm",[282,283,285],"h3",{"id":284},"ring-modulation","Ring modulation",[15,287,288,289,292,293,296,297,299,300,303],{},"FM changes the carrier's ",[25,290,291],{},"pitch",". What if the fast signal changes its ",[25,294,295],{},"volume"," instead? Patch an oscillator into a VCA's ",[30,298,190],{}," and the VCA multiplies the two signals together. This is ",[30,301,302],{},"ring modulation",": it produces new tones at the sum and difference of the two frequencies, and often loses the original notes altogether. Bells, robots, and the Daleks.",[15,305,306,307,309,310,312],{},"In the bell patch above, try patching the left VCO's ",[30,308,83],{}," straight into the ",[30,311,190],{}," of the VCA under the ADSR.",[35,314,316],{"id":315},"drive-pushing-a-signal-too-hard","Drive: pushing a signal too hard",[15,318,319,320,323,324,328],{},"Turn a signal up too far and it can't get any louder; the tops of the wave get squashed flat. That squashing is ",[30,321,322],{},"distortion",", and it adds harmonics. A smooth wave goes in; something edgier comes out. The ",[19,325,327],{"href":326},"\u002Fmodules\u002Fdrive","Drive"," module has three ways of doing it:",[92,330,331,337,343],{},[95,332,333,336],{},[30,334,335],{},"SOFT"," rounds the peaks gently: warm saturation, like a tape or tube pushed a little.",[95,338,339,342],{},[30,340,341],{},"HARD"," chops them off: fuzz.",[95,344,345,348,349,352],{},[30,346,347],{},"FOLD"," does something stranger. When the wave hits the ceiling, it ",[30,350,351],{},"folds"," back down on itself instead of flattening. Push harder and it folds again, and again. Each fold adds more harmonics.",[15,354,355,356,359],{},"That last one is special: with folding, ",[25,357,358],{},"how hard you hit it"," changes the tone, so turning the input level up and down sweeps the brightness, a bit like a filter in reverse. This style is often called \"west coast\" synthesis, after the Buchla instruments from California, where it started.",[118,361,364,370],{"lesson":362,"title":363},"13-drive-and-wavefolding","Fold a sine",[15,365,366,367,369],{},"A plain sine goes into the Drive on ",[30,368,347],{},". An LFO on the VCA in front of it rides the level up and down. Watch the scope: blue is the smooth sine going in, pink is the folded wave coming out.",[92,371,372,382,394],{},[95,373,374,375,377,378],{},"Turn up ",[30,376,327],{}," for more folds. ",[255,379],{"module":380,"param":380,"above":381},"drive","15",[95,383,384,385,387,388,390,391],{},"Try ",[30,386,335],{}," and ",[30,389,341],{}," for warmth and fuzz. ",[268,392],{"module":380,"param":393},"mode",[95,395,396,397,400,401],{},"Click ",[30,398,399],{},"BYP"," on the Drive to compare with the plain sine. ",[255,402],{"module":380,"param":403,"is":122},"bypass",[35,405,407],{"id":406},"bitcrushing-digital-on-purpose","Bitcrushing: digital on purpose",[15,409,410,411,415],{},"Digital audio is a long list of numbers, each one a snapshot of the sound. A ",[19,412,414],{"href":413},"\u002Fmodules\u002Fcrush","Bitcrusher"," makes that list deliberately worse, like an old games console or a cheap sampler:",[92,417,418,424],{},[95,419,420,423],{},[30,421,422],{},"Bits"," sets how many volume steps each number can have. Fewer steps means gritty, buzzy noise. 16 bits is clean; 3–4 is wrecked; 1 is pure square-wave grime.",[95,425,426,429,430,87],{},[30,427,428],{},"Rate"," holds each number for several samples in a row, which creates metallic, robotic tones that weren't in the original. This is called ",[30,431,432],{},"aliasing",[118,434,437],{"lesson":435,"title":436},"14-bitcrusher-lo-fi","Ruin it nicely",[92,438,439,447,455],{},[95,440,396,441,443,444],{},[30,442,399],{}," on the Bitcrusher to hear the clean version, then crush it again. ",[255,445],{"module":446,"param":403,"is":122},"crush",[95,448,449,451,452],{},[30,450,422],{}," 1: maximum grime. ",[255,453],{"module":446,"param":454,"below":259},"bits",[95,456,457,459,460],{},[30,458,428],{}," ÷40: everything turns into a ring-modulated robot. ",[255,461],{"module":446,"param":462,"above":463},"down","38",[35,465,467],{"id":466},"glitch-breaking-time","Glitch: breaking time",[15,469,470,471,474,475,479,480,483],{},"Distortion bends the ",[25,472,473],{},"shape"," of a wave. ",[19,476,478],{"href":477},"\u002Fmodules\u002Fglitch","Glitch"," bends ",[25,481,482],{},"time",". It remembers the last few seconds of whatever goes in, and now and then replays bits of it: stutters, reverses, octave jumps, tape stops. Because it listens to the clock, every glitch lands on the beat. Wrong, but in time.",[118,485,488],{"lesson":486,"title":487},"33-glitch-break-it-on-purpose","Break a drum loop",[92,489,490,502,512],{},[95,491,492,493,496,497],{},"Set the Glitch's ",[30,494,495],{},"Chance"," to 0 to hear the untouched loop, then creep it up. ",[255,498],{"module":499,"param":500,"below":501},"glitch","chance","0.02",[95,503,504,507,508],{},[30,505,506],{},"Density"," to 100%: machine-gun rolls. ",[255,509],{"module":499,"param":510,"above":511},"density","0.98",[95,513,514,517,518],{},[30,515,516],{},"Warp"," chooses between plain stutters and reverses, octave jumps and tape stops. ",[268,519],{"module":499,"param":520},"warp",[35,522,524],{"id":523},"taking-away-adding-in","Taking away, adding in",[15,526,527],{},"Filters and these techniques work best together. A classic move is to add harmonics with FM or drive, then shape the result with a filter and an envelope. Make it rich, then sculpt it.",[35,529,531],{"id":530},"what-to-remember","What to remember",[92,533,534,539,544,551,556,565],{},[95,535,536,537,87],{},"Modulation faster than about 20–30 times a second stops sounding like movement and becomes ",[30,538,56],{},[95,540,541,543],{},[30,542,71],{},": a modulator oscillator wiggles a carrier's pitch. Simple pitch ratios sound musical and bell-like; odd ratios sound metallic.",[95,545,546,547,550],{},"An envelope on the ",[30,548,549],{},"FM amount"," makes notes bright at the start and mellow as they ring.",[95,552,553,555],{},[30,554,285],{},": an audio signal into a VCA's CV multiplies two sounds into new ones.",[95,557,558,560,561,564],{},[30,559,327],{}," squashes or folds waves to add harmonics; with ",[30,562,563],{},"folding",", louder input means brighter tone.",[95,566,567,387,570,572],{},[30,568,569],{},"Bitcrushers",[30,571,499],{}," effects add digital grit and break time, on purpose.",{"title":574,"searchDepth":575,"depth":575,"links":576},"",2,[577,578,582,583,584,585,586],{"id":37,"depth":575,"text":38},{"id":65,"depth":575,"text":66,"children":579},[580],{"id":284,"depth":581,"text":285},3,{"id":315,"depth":575,"text":316},{"id":406,"depth":575,"text":407},{"id":466,"depth":575,"text":467},{"id":523,"depth":575,"text":524},{"id":530,"depth":575,"text":531},"How to add harmonics instead of removing them. What FM synthesis and ring modulation are, why audio-rate modulation makes bells, and how drive, wavefolding, bitcrushing and glitch effects change a sound.","md",{},"\u002Flearn\u002Ffm-and-distortion",{"title":5,"description":587},"FM synthesis, ring modulation and wavefolding explained for modular beginners","learn\u002Ffm-and-distortion","G-Kc9eNQrC5wbCpHI-hL2mav4J-8179IrUzsVnmiCNg",1792599837968]