Happy New Year everyone! I hope your holiday period was less mired by illness than mine. One of the benefits of not feeling up to leaving the house was that I had time to make a demo video for my Glitch Delay Eurorack module.
The effect is designed around the Teensy 3.6 dev board. I designed the PCB in Eagle and had a small batch manufactured. This is very cheap to do nowadays, only a couple of pounds per board.
The effect consists of a standard delay line, or delay buffer, with multiple read heads that each read the audio in a different way. There is a feedback path, so the effected signal can be feedback into its self.
There are 2 types of read head:
Loop heads – These heads loop small sections of audio. There are 3 of these. One that plays the audio an octave lower, one at the original octave, and one an octave higher. The size of each of these loops can be adjusted (size dial), as can the amount the loops move each time the loop starts again (jitter dial)
Reverse head – This head plays the buffer in reverse at the original octave.
The top white button allows you to set a tap tempo. This forces the looping heads to jump to a new position on every beat.
The bottom white button is the ‘freeze’. This freezes the write head. No new audio will be written into the buffer, the old audio will remain. This essentially ‘locks-down’ the audio, so it can be tweaked without the buffer changing.
How can I build one?
The source code for the firmware running on the Teensy 3.6, and the schematics for the PCB are available on GitHub here
I shall post soon with more details of how to go about creating your own.
Can I use this in software?
Yes! I’ve ported the code to the JUCE framework. You can compile it yourself or download the executables from the GitHub here.
There are still some issues to resolve. The output can be a little noisy. This noise comes from the 5v offset applied to the incoming audio. This is mainly a gain-staging issue, and could be resolved by having an additional potentiometer to scale the amount of bias applied to the incoming signal. There is another issue where the module occasionally fails to power up. I believe this is due to occasions where the 12v line takes a little time to stabilise, which results in the 5v regulator supplying the Teensy with a voltage of less than 5v for a short period, which causes the Teensy to crash. I have a workaround for this in mind though.
I plan to build an expander module which will connect via I2C which will add CV control of many of the parameters. Check back for updates..
I’ve spent quite a lot of this year (when I wasn’t working on the album) designing a new Eurorack module. It’s inspired by some of the demos I watched of Lines running on the Aleph (by Monome). I’ll be putting up more details soon, but it’s a glitchy digital delay/granular effect running on a Teensy 3.6. I plan to put together a video soon!
This weekend I built a DIY Euroack case out of a cheap tin lunchbox from eBay. I want this case to house some of my Teensy based modules and form an all-in-one guitar focused effects box. The project was reasonably straightforward. I used one of these power boards which supplies +12v/-12V from a 14-24V DC power supply. The board that the ribbon cables connect to is vero board with single header, doubled up. Everything was mounted using 11mm M3 brass stand-offs. The wooden rails are possibly a little thick and will limit the size of the PCB under the module panel. Will have to see how that goes. Putting in thinner rails should be feasible. All holes drilled with my new pillar drill. Much easier, with far less swearing than trying to use a standard power drill. The overall project build cost was around£20. Looking forward to filling this with my DIY modules!
I now have a permanent space to build things that go beep and grrrr-beep, in a shed we’ve built in our garden. The other half is reserved for my wife to do dress making. A veritable temple of hobbies! Expect more machines in the near future. I’ll soon be doing some videos of the things I make – watch this space.
Cutlasses scores the latest episode from the excellent radio play series ‘Whisper Through The Static’. The episode is called Korol Cheyva, click the link to listen. I highly recommend checking out some of the other episodes too, they’re great!
The debut Cutlasses album ‘Clutching at Conscious’ is out! Finally. I feel like it has consumed every ounce of my spare time, and spare thoughts, but I’m very happy with the outcome. You can listen to it, and buy it here or just click on the Music tab. We had the launch party last night, thanks so much to everyone who came, I had a great time, I hope you did too! I’ll probably write a little bit about the construction of some of the tracks, but for now, please listen, and enjoy.
For my gig at Thee Sunday Sonics this weekend I decided to make a new USB controller. I was previously using one with many more buttons and knobs than I actually needed. For this project I used the Teensy LC. A low cost version of the Teensy (around £10). It has less memory and computation power than the 3.2, but more than enough to make a simple USB MIDI controller. I used a mustard tin to house it all in. It’s suspended inside using these. It worked a treat in practise but for some reason on the night of the gig (typically), in soundcheck it stopped working and seemed to be interfering with my other controllers. Luckily I bought my previous controller as a spare. Still not entirely sure what the issue was (it works fine again now). My best guess is that there was some form of power issue. I’m hoping to be able to recreate in an environment that not on-stage so I can actually resolve it.
Once I’d reverted to my spare everything was fine, and the gig went well. Thanks to Thee Sunday Sonics for inviting me, it was lots of fun.
[EDIT] I’m fairly confident I’ve solved the problem. The software wasn’t consuming and discard MIDI messages it received, only sending its own messages. Updated code on GitHub