Phase

Phase is a phase distortion synthesizer written for the pocket chip. It has two individually tuned oscillators with controls for ring modulation, adsr, 4 - 32 point phase distortion, 8 point pitch adsr and distortion adsr. Further shape the sound with a stereo delay, phaser and chorus. Play the three playmodes: 4 voice polyphonic, monophonic or arpeggio with the pocket chip keyboard or by plugging in a usb midi device.

Updates

Phase 1.1.1

• Fixing keyboard auto repeat issue on exit.

Phase 1.1

• Fixing midi note off bug for keyboards hacking the velocity parameter.
• Adding up-down arpeggio.
• Updating arpeggio to sort by note order.
• Fixing gain issue.

Installation

Keep Calm

Don't panic. Keep calm. As a person growing up with mostly graphical interfaces I know that teminals can seem a bit scary at first, but don't worry. It is not that hard really. If you are completely new to the unix terminal, here are a few common commands that might be helpful.

List directory content:

ls

Change directory:

cd <directory>

Create new directory:

mkdir <directory>

Super user:

sudo <command>

Edit with nano, a useful text editor:

sudo nano <file>

Kill process (SIGINT), can be used to stop phase if exited by pressing home:

ctrl + c

Installation

Create a new directory or pick an existing one of your choice to place the phase files in, for example /home/chip/phase. Cd into the new directory and download phase:

curl --remote-name http://www.humbletune.com/phase/chip/phase.zip

Unzip the executable file:

unzip phase.zip

Next we need to setup the audio by editing .asoundrc. On the pocket chip this file is found in /home/chip. I also recommend setting the sample rate to 22050 Hz, which will make it a bit easier for the pocket chip to do all its processing in time. 22050 Hz still plenty of range to produce the frequencies needed. My file looks like this:

pcm.!default {
	type plug
	slave.pcm "dmixer"
}
pcm.dsp0 {
	type plug
	slave.pcm "dmixer"
}
pcm.dmixer {
	type dmix
	ipc_key 1024
	slave {
		pcm "hw:0,0"
		period_time 0
		period_size 1024
		buffer_size 8192
		rate 22050
	}
	bindings {
		0 0
		1 1
	}
}
ctl.mixer0 {
	type hw
	card 0
}
pcm.phase {
	type plug
	slave.pcm "dmixer"
}

curl --remote-name http://www.humbletune.com/phase/chip/.asoundrc

Pcm.phase is what phase will use to tap into the alsa sound mixer. If you choose to use a different sample rate than the default 22050 Hz you will need the otherwise optional settings file. To the same directory you installed phase, download an example settings file:

curl --remote-name http://www.humbletune.com/phase/chip/settings.json

Now reboot the chip to make it use the new sound settings:

sudo reboot

Before running phase you might have to set permissions to execute the program, for example you could do:

chmod 755 *

Run phase with the following command:

./phase

Another useful command to find out the midi devices that are availabe is:

amidi -l

Raspberry pi

Running phase on a raspberry pi is very simillar to on the pocket chip. Instead place the files in /home/pi/phase and no asound.conf or .asoundrc is neaded. Download phase:

curl --remote-name http://www.humbletune.com/phase/pi/phase.zip

Next download an example settings file for the pi:

curl --remote-name http://www.humbletune.com/phase/pi/settings.json

Finally run phase as a super user, this will allow the program to set the hight priority on the sound thread that is needed:

sudo ./phase

A Little Sound Sample

User Guide