synthvoice

[ITP: Designing Your Voice] Inter-FACE?!

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Idea

For my synth final I wanted to make something that could be a part of my thesis, my Body of Work. My thesis is a series of sculptures that depict my body parts. I developed this idea of creating an “interFACE” synth. I wanted to create a sequencer that would play back body sounds and kind of looked like my face.

Sketch

Here are some crazy sketches I did over the course of the last couple of weeks:

Samples

The first step was recording samples. My buddy Josh lent me his lil mic set up and I recorded some weird “body sounds” on my phone.

I then trimmed them up and converted the .mp4 files to .wav on my computer. I think I did this in the Music app (FKA iTunes) but I don’t quite remember how.

open file in music, import settings —> WAV encoder, File -> conver —> create wav version

Then I used the wav2sketch package to convert all my .wav samples into C++ files which can be stored directly on the Teensy’s memory! Playing samples back from the Teensy’s on-board memory has a lower latency than playing back from the SD card reader. It is really crucial that the .wav files are at 44100 Hz and 16 or 8-bits for conversion. More instructions can be found in Jesse’s slides.

Later on I realized that I needed the samples to be at the same volume for a better sound experience. I tried messing around with gain values in my code to amplify selected samples but I didn’t get the effect I was looking for. I downloaded Audacity which is a free and open-source audio tool and used the “loudness normalization” effect to get the samples all the same volume.


do not use a4

Process

started by making a four step sequencer with jesse’s code

then mapping the samples to 1 knob

then make 8-step sequencer with LEDs

Add knob to control speed

This is where my circuit started

Big mess

Current circuit

Then, interface with the brain

Blinking an extra digital pin on brain, using that to trigger next step

Code

(Some) Fabrication

No experience with casting. Also, casting the face orifices … problematic!

Life cast —> plaster

plaster —> silicone mold —> resin knob

Next Steps

lol lots

volume knob

button to switch between regular clock and trigger/CV inputs

RGB LEDs

1-2 more samples … need to capture laugh…

resin time + face plate fabrication

future future future : oscillator + ADSR modules

Resources

Jesse’s lecture with wav2sketch

Audacity Loudness Normalization tutorial

interFACE code repo

[ITP: Designing Your Voice] Final Project Planning

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Gather samples of body

Make knobs

Gate sequencer vs. pitch sequencers

Plug into brain?!!?!

you can never have too many vca’s

  • VCAs allow us to inject animation into our patches

    • Let us change the volume of signals over time

    • Change the “volume” of control voltages (CVs)

  • Use a VCA to build things:

    • Compressor, side-chain a kick (?), AM synthesis

    • Intermediary to modulate modulators

  • Moog DFAM

  • VCA’s can have character, not always clean

  • Input, output, control voltage (controls how loud)

  • VCAs to create voices, filters out sub-base mud, closes voice down

  • AM synthesis - plug another oscillator into CV control, oscillators kind of combine

  • Using a sequencer to change the volume of another pitch sequencer output

  • Static vs. animated

arpeggiator code

https://brendanbyrne.info/Theseus-1

https://www.youtube.com/watch?v=6i_DgFkcAxk&list=PLBvnHGvQhLl0YpfJwEvFw_nmJGDnw_A-t&index=1

https://doudoroff.com/sequencers/

https://www.youtube.com/results?search_query=step+sequencer

https://www.youtube.com/results?search_query=teensy+sequencer

Resources

Why you can never have too many VCAs

Expert in modular synths

Contact mic tutorial

Contact mic club

https://www.youtube.com/watch?v=HiatLBJoWIc

[ITP: Designing Your Synth Voice] Ornament and Crime

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ornament & crime, o_C

  • Eurorack module running off of a Teensy 3.2

    • Basically a DAC breakout board with OLED display

    • It’s a “polymorphic CV generator”

      • Polymorphic = something that has multiple forms (?)

  • 4 precision CV outputs, 4 CV inputs

  • This is a post-capitalist, open source project

  • Comes with 10 different apps

    • Digital ASR (analog shift register) called “copier machine”

    • 4 channel pitch quantizer

    • Wave table quad LFO

    • Quad VC envelope generator

    • Etc, etc, etc

Control Voltage (CV) refresher

I watched these two weird videos from the Moog Foundation about CV. Here are my key takeaways:

  • “Voltage control just acts as a means of control that’s just like a hand on a knob”

    • It’s a robot hand, which you can tell what to do in a way that you want it

  • Simple electrical automation to cause changes over time using voltage

reverb and shimmer

Teensy Examples

TB303 Acid Button Press

Button 0 triggers an envelope and plays a random note in a hard coded scale. Button 1 cycles through the different wave types. Button 2 changes the octave of the notes. A15 is the filter attack time, A16 is the filter resonance, A17 is the envelope release time

TB303 Acid Generator

The gui output is the same as the example above. This sketch plays continuous tones to the Teensy’s audio output, a random note from a hard coded scale. The tempo of the playback can be changed by adjusting the potentiometer on A14. A15 affects the filter attack time. The knob on A16 affects the filter resonance. A17 affects the envelope release time.

To the right is the serial monitor output which prints the current MIDI value and its corresponding frequency.

Random Gate Generator

This sketch is basically just the blink sketch but on a random interval. This can be used to trigger external microcontrollers or hardware.

A gate is a signal type that is passed around inside a modular synthesizer. It jumps to a high level when a new note is supposed to start and stays “on” for the notes duration.

Resources

https://ornament-and-cri.me/

Ornament & Crime tutorial/review

What is polymorphism?

O & C on PJRC

O & C quantizer tutorial

O & C chord generation tutorial

CV from Moog Foundation 1

CV from Moog Foundation 2

Week 6 Teensy Examples

Gate definition

[ITP: Designing Your Synth Voice] I've Burntout!

in

Lol I’m so done, but remember this?!

I recently found this slide from Jesse’s earlier lectures and I think I should keep on referring to it! It’s so hard to understand what kind of stuff will go into the final modules we’re supposed to create for this class but this visual makes it more digestible. Maybe I will make a synth with all of that stuff in it?!

Week 5 Teensy Examples

wav2Sketch

wav2Sketch is a library that converts wav files into data arrays that can be played from on-board memory. This example triggers a different wav file to be played when one of the four buttons is pressed.

This is what my teensy setup is looking like these days!

Basic sampler

This example works the same as the previous one except that the wav files played are uploaded to an SD card and installed into the audio shield.

C Major seventh

Alriiiiight, below is what the gui output looks like, but I’m having a hard time understanding how the code works. The voice1Setup() functions are all called in the sketch's setup() function, so they are only executed once. I can see that the function is assigning a note (frequency) from the c major scale to a waveform but I have no idea what the potentiometers are doing in that case. So buttons 0, 1, 2, and 3 are playing 0, 2, 4, and 6 of the c major scale. The last button, 4, changes the octave of the scale.

Midi C major seventh

The gui for this example looks exactly the same as the example above. Here, instead of using specific frequencies for the notes, we are using midi to define the notes of the scale (and the midi to frequency library). I don’t think the fifth button (button 4) does anything. Nothing seems to change when I turn the knobs either.

I think the purpose of modulating the waveform and putting it through an LFO is what gives the notes that dreamy, vibe-y, echo-y bedroom pop sound.

Memory Usage

This example is playing a pink noise + sine wave note repeatedly. I have no idea what the Fast Fourier Transform is doing. The sketch prints out the memory usage of the various stages of the code. It can help to determine if you need to allocate more or less onboard memory to run a sketch. Sending “s” over serial slows the speed of the sketch and “f” makes it go faster.

Jesse’s VCV Rack Demo

I went through Jesse’s VCV Rack demo and this is the patch I ended up with (lol the same one he showed). I really found following along with this video to be super helpful in my understanding of patching. Below I collected some of my notes.

  • MIDI = messaging protocol which can contain information about pitch, trigger, velocity, etc

  • VCO = voltage controlled oscillator

  • VCA = voltage controlled amplifier —> signal intensity

  • CV = control voltage to modulate a signal

  • ADSR = attack, decay, sustain, release in terms of an envelope

  • Gate output —> gate input?

  • V/OCT connection gives different pitches (voltages) for the MIDI keys/notes

  • VCF = voltage controlled filter (low pass, high pass, band pass), adjustable frequency cut off

  • Quantizer = mapping frequencies being played to the nearest active value of the quantizer

Assignment

I would really love to make an arpeggiator! Gonna ask Jesse for some help!

Resources

Jesse’s week 5 examples

PJRC Audio Gui Tool

Jesse’s VCV Rack demo

[ITP: Designing Your Synth Voice] Group Work??! Yuck

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In class examples

Here were some VCV rack examples we did in class 02/12/24. These might be helpful for future Priyanka (or anyone else).

Amplitude oscillation

Frequency oscillation

Envelopes —> ADSR

Sequencer

Quantizer

Also in class we learned about line inputs and outputs. Line level is a standard used typically with gear that has the ability to adjust the volume/gain, such as a mixer or amplifier. It’s approximately 1.75V which is not enough to power headphones. The Teensy audio shield has mono left and right channel outputs.

Assignment

Hi Jesse. This week I organized the Stupid Hackathon and mentally I am here… everybody shut up on this floor. Everybody shut up in this department.

This week I got a new breadboard and a Teensy 4.1 because I realized I would quickly run out of IO pins on the 4.0. A big task for me was soldering all the headers for my new Teensy and getting my buttons and potentiometers set up again.

This was a two week assignment to use the line in/line out pins to patch into another person’s synth setup. I was on a three person team with Tres and Q. This was kind of a brain-breaking practice because I had an untested, brand new setup and I think Tres was having some hardware issues.

We started with the pass through example, which seemed to work for me and Tres. Then we tried to get all three synths working together. Here’s some documentation of us jamming together. Tres’s line out was connected to my line in and my line out was going into Q’s line in. I’m not really sure what’s going on here. Tres has some LFO and modulation going on. I tried getting the reverb example going. Q also had something going on in their setup but the best part was the drum they had setup on the button (you can hear it at the beginning of the clip). Overall, no idea whats going on…

Code Examples, audio pass through

Wav player

Delay module

Bitcrusher module

Filter module

Envelope module

I’m also really curious about building a sequencer at some point, I think. I watched some videos and saw people’s really cool synths they’re making. I’ve linked some inspo’s below for future reference.

Resources

Everybody shut up in this world

Jesse’s week 4 examples

David Wieland’s sequencer module

Praj’s Portable synth documentation (comprehensive)

Praj building his synth (with Teensy)

Brendan Byrne’s Theseus

[ITP: Designing Your Synth Voice] Synth Club and Envelopes

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IDM Synth Club with Luke Dubois

Do not miss an opportunity to check out the IDM Audio Lab. Go there!

The lab is open to everyone and the people involved there are very knowledgeable. I went with Tres and we still don’t know enough about synths to get any sounds/beats working on the Serge modular synth we had some fun messing around with synthesizers that are non-modular (the ones with piano keys!). They provide super thorough documentation on how to use the synths on their website.

VCV Rack

I downloaded and played with VCV Rack a bit. I don’t really know what I am doing yet but it is fun to see how turning the knobs and changing up the patches changes the sound output. It will be good to use this to prototype different patches.

Envelopes, VCA, LFO

I’m not getting audio out of my headphones anymore when they’re connected to my teensy so I wasn’t able to complete this homework yet.

I have, however, been thinking about what my completed synthesizer might look like. I’m hoping to make an interFACE as part of my thesis which is about self-portraiture, sculpture, interface, and embodiment! Here’s a CRAZY scribble on some things I’m thinking about:

[Update 03/08] Examples from Class

This code comes from Jesse’s GitHub repo. I’m finding it helpful to go through the examples and see if I can understand what’s going on in synth land…

Envelope with harmonics

One button triggers the envelope (or the playing of a note) and another button cycles through different wave types (sine, pulse, triangle, sawtooth, and square). When you press the trigger button, four waveforms play all at once, one octave apart, creating harmonics. Four potentiometers control the attack, decay, sustain, and release of each note.

Envelope with harmonics and filter with LFO🤯

The two buttons have the same function in this example. One button triggers the envelope but there’s a continuous signal playing simultaneously —? don’t really know whats going on in this one

It is at this point that I had a 1.5 hr office hour with Jesse because I had some weirdness with my circuit and turns out I do not know how to wire up a button!!!!🤬

Now that I think this hardware and sketch is working as it should, I can confirm that the two buttons and the potentiometers have the same functions as the earlier example but the potentiometer on A17 adjusts the frequency of the LFO. As I increase the LFO frequency it increases the speed and the number of wobbles I heard on the audio output.

Noise Envelope

This example plays a series of noise envelopes. Each button calls a function that shapes the noise into a hi hat, swell, click pop, or keyboard key sound. A potentiometer adjusts the amplitude of the envelopes.

FM Voice LFO Modulation

This example actually only uses one button. The potentiometer on A14 adjusts the frequency of of waveform 1. Potentiometer A15 adjusts the amplitude. The potentiometer on A16 adjusts the frequency and A17 adjusts the amplitude of waveform 2. From what I can understand, waveform 1 is the modulator frequency for frequency modulation of waveform 2.

FM Voice LFO and Envelope Modulation

I am not actually sure what this example does but it sounds cool. When I press button 0, it plays a note which kinda sounds like a laser gun sound effect. Turning potentiometer A17 seems to make the note longer and A14 seems to change something with the pitch. From looking at the code, I don’t think A15 does anything.

Code LFO

A low frequency oscillator is inaudible and modulates signals to slowly alter parameters over time. Button 0 triggers the envelope and button 1 changes the shape of the wave. This code generates a sine wave LFO (attack) and the potentiometers control the decay, sustain, and release of the envelope.

[ITP: Designing Your Synth Voice] Baby's First Synth

in

For this week’s homework, I set up my Teensy 4.0 and the Audio Shield using the Audio Workshop tutorial from PJRC as a starting point. Here’s how my hardware is hooked up for now:

While I’m just getting started with analog synthesis, I thought I would just go through the examples shown in class.

Waveform

This example just lets you adjust the frequency of waveform output by turning a potentiometer. The i2s block is included in basically all applications of the Audio Library because it transmits 16-bit stereo audio to the shield.

Waveform with button cycle

This example is the same as the last one but you can cycle through different shape for the sound wave (sine, square, triangle, pulse, sawtooth) using a button press. Same flow diagram as the previous example.

Harmonics

Again a button controls the shape of the signal. The sketch plays a waveform and signals one and two octaves below. Potentiometers control the gain of the three waves. The mixer block combines up to four audio signals together.

Mixer software block

Harmonics with filter

In this example, the button does its thing. The first two potentiometers control the gain of a base frequency and its harmonic (base frequency / 2). The third potentiometer changes the cutoff frequency of a low pass filer.

Detuning

In this example, the first potentiometer controls the base frequency. A second potentiometer controls the detuned frequency. I’m pretty sure when these two waves are played at the same time it creates beats.

Detuning with filter

Same detuning strategy as above but the third potentiometer controls the cut off frequency of a high pass filter.

I ended up skipping the last example from the class Github because it required SD card playback. Don’t have one of those yet. One weird thing I did encounter is that the headphone jack on the Audio Shield is a little bit iffy. Like my headphones need to be plugged in at just the right depth to heard any audio, bumping it could affect the output…

References

Class 2 Github repo

PJRC Audio Workshop Tutorial

[ITP: Designing Your Synthetic Voice] Cringe Comfort

in

I used to have a much stronger relationship with my music taste. My taste in music used to mean so much to me and was a big part of my identity in high school. I mostly listened to emo, rock, alternative, bla bla in my formative years. I used to rip and burn all my friends CD’s and go to concerts. I took pride in being a snob haha. Music was such a big part of my life, I had played classical piano for years, violin in my high school orchestra, and even picked up guitar for a bit. Here I am playing a song at my senior recital.

It got too exhausting trying to keep up with all the more informed music-people so these days I’m a really casual listener, maybe even too casual. I’ve lost track of my own tastes and preferences. I’ll basically listen to whatever Spotify tells me I like.

Voice of the past

Usually I prefer music played by a band with traditional instruments, a lot of like indie, folk, and R&B, but I started to think a bit about my relationship with electronic music. I listened to some albums that I still really like that have some electronic components and tried to identify what I liked about them. Here are some era’s of past-Priyanka music taste:

Height of 2012 indie hipster cringe core

It wasn’t cringe at the time, but I sometimes do looking back on what I loved. Cringe isn’t always bad, I think it’s something to lean into! Listening to this music made me into the person I am today. We’re talking Washed Out, Passion Pit, The Postal Service, Crystal Castles, Grimes, MGMT, Kishi Bashi …

One of my favorite albums from that era is Merriweather Post Pavilion by Animal Collective.

What I like about it: floaty, mushy, reverb, airy, sparkly, punchy, vocals, what’s he saying?!, kinda feels like you’re outside, daylight, rhythm

80’s alternative synth pop? art pop? dream pop?

Think Talking Heads, Kate Bush, and Cocteau Twins. Honestly, I’m so music illiterate, I’m not really sure if these truly fall under this genre. I feel like I can hear electronic components in this music sometimes, but are they even using any synths? Maybe!

Brotherhood by New Order

What I like about it: dark, crisp, fast, dynamic, sharp, moody, gloomy, whiny

90s House: World Clique, Deee-Lite

I guess I don’t really listen to any other 90s house but I had a phase where I listened to this album a lot.

What I like about it: punchy, beat, bass line, simple lyrics, simple melody, dance, fast, fun, repetitive, catchy, funky, organ, hard yet moments of softness, samples

<3 Mort Garson’s Plantasia <3

Real analog synth, right?! His artist profile pic on Spotify shows him sitting in front of one, so it better be!

What I like about it: whimsical, magical, can visualize a plant growing, triumphant, melodic, rhythmic, charming, uplifting, can focus on other things while listening but interesting enough to focus on the music as well

Makin my own electronic music

I also just remembered that I took a music technology class in my undergrad. We learned to work with DAW’s like Logic Pro and Ableton and I think I even messed around with the SuperCollider programming language. I uploaded some of my weird experiments to this SoundCloud profile.