Tuesday, December 21, 2010

OT: New music website thingie..

I've finished a new website for my various musical projects (not really DIY-related). So now instead of pointing people to a myspace, I can just send them to this:


Sunday, December 12, 2010

Crushed Glass granular sampler/looper/glitcher

This is something I've been working on (on-and-off) since january or febuary of '10. For DIYers, looping is usually restricted to ISD sound recorder chips. They are neat but don't offer a whole lot of flexibility. I wanted totally random access to individual samples for some pseudo-granular drones so I saw what I could do with microcontrollers. Initially I had started learning dsPICs, but later put it aside and went with what I knew, the 8bit AVR.

I'm using SPI RAM which isn't the fastest solution but I just wanted to see if my ideas could be done. Fidelity was secondary. I went with the ATMEGA328 which is the chip with the most amount of internal RAM in DIP format. I didn't want to use the larger 40-pin DIPs.

I wanted to be able to ping-pong the "playback head" in as little time as a 1ms sample window, define start and end loop points, among other things. That meant quite a bit more code that simple record and playback. Keeping it tight, I still manage up to 12KHz sampling on the 8-bit uC. Considering there's a lot of SPI communication with both RAM chips and the DAC, I don't think that's too bad. Stuff like LED updates and potentiometer sampling only happen around 20 times a second. I use an additional uC (atmega88) on a daughter board for the 16 LEDs. It serves as a 4-to-16 decoder.

On the less technical side, sound-wise it is pretty lofi. It doesn't handle complex recordings well. Stuff like full chords, mixed-down songs, things with a lot of harmonic detail and smooth volume dynamics. Some complex things work, most don't. What it does handle well is individual monophonic instruments (or picking single strings on a guitar), some vocals, cicuit bend noises, and it handles electronic beats really well!

The controls are really counter-intuitive, and for this reason I won't be building these for anybody just yet. There are some bugs and limitations that I have not been able to fix in the weeks and months of work. The problem is that I designed this back-to-front which is a really bad way of doing things. I started building a looper then later tacked on features. It's all duck-taped and bandaided together with tricks and hacks in the code. What I should of done is figure out my features first, then design around that. Because I did the reverse, fixing the bugs and limitations have been so difficult that I'll have to start over if I intend to sell these. Personally I can live with these quirks, but I can't help but think others would be confused.

The next one will be much better!

A list of features/controls, some more technical information and a video below.

- Input gain (with red clipping LED)
- Independent Dry and Wet knobs
- Record / Playback toggle switch (with purple rec LED)
- Hard bypass toggle switch (with orange LED)
- Low pass filter
- 16 LED "head" position
- Speed, sets the samplerate
- Start and End realtime sample trimming
- Trim drift/gradual offset
- Confusion knob which does ping pong stuff to the "head"
- Direction knob sets forward or reverse, or glitchy in-between madness!

Main CPU: ATMEGA328 (overclocked to 12mhz at 3.3v)
Secondary CPU: ATMEGA88 (for 16 LEDs only)
ADC: internal 8bit
DAC: external 12bit MCP4921
RAM: two 23k256 ICs
LPF: MAX7403
Programmed in BASCOM

Thanks for reading/watching!

Saturday, June 12, 2010

3 bitcrushers for sale *SOLD*

as of now.

$150 US
tracked and insured shipping is around $15 to north america. contact me if elsewhere.

Check the blog post down below. Some samples are there. has samplerate reduction, bitcrushing on an 8-position knob, wet/dry blend and volume. good for lo-fi effects, nintendo/atari sounds, weird digital fuzz, glitches, etc. great on synths and drum machines too! does a good job killing fidelity! when turning up the volume and harshness, with the wet/dry knob all the way "dry", it's not totally dry. more like 96% dry. uses 9v DC standard boss-like adapter. not included. Meant as a non-subtle effect but subtle can sort of be dialed in. Full refund if you dont like it (assuming it's in okay condition, and minus shipping). will try and ship before monday.


Thursday, June 10, 2010

Moth bitcrusher sale

I'll have three bitcrushers for sale in a few days.

two samples. both tentatively co-titled the-art-of-dicking-around. I have no idea what I'm doing. I've never been good at recording dirt-only stuff, at least without some kind of backing.


they'll officially go on sale sometime on saturday for $150 US each, but only as of when I update this blog on that day saying so. so please no emails ahead of time. when the time comes, you can reach me at:

eblythe (aaaat) mochamail (dooooot) com

Friday, May 21, 2010

Thursday, April 29, 2010

Sonic Crayon Moth + Hollow Earth plans


Things have been lagging due mostly to demotivation re: the hollow earth. That sucker is tough to build, I mean really tough. it's definatelly not dead, though, and as a way to help kick-start things back up again, I'm selling off a batch of bitcrushers/samplerate reducers with wet/dry blend control. it's an easy build I'll have no trouble building a dozen of, and at the same time it'll help refinance the whole hollow earth gig.

So here's the bitcrusher, called the Moth and does 1-8 bit crushing and samplerate reduction. there's wet/dry blending and volume as well. the graphic will change a little. here's a bad clip. I'll do a youtube once things are orginized.

there will be no reservation list for this one. in a bunch of weeks I'll just announce a day they go on sale and that'll be that. $150 a pop.

in semi related news, the kind folk at Audio Effekte have written a kind word on this project of mine, as well as about montreal assembly!

read it here

You should check out Scott's stuff (at mtl assembly). he makes rad effects too and his bitcrushers are way more versatile than mine! face-melting boxes galore!

Saturday, April 3, 2010


..I'm thinking of doing a small run (10) of simple samplerate reduction pedals to try and kick things back up again. Two knobs (blend and samplerate), simple circuit, etc. 10x easier than the hollow earth and would help fund/re-enthusiate an eventual hollow earth reincarnation.


Tuesday, March 23, 2010

Hollow Earth non-update

I'm super late with Hollow Earth orders, in case you were wondering.
big surprise

Sunday, February 14, 2010

of floopers and bitcrushers

A quick flooper (feedback looper) I built for the Pines. Saw it in action at a show last night, awesome!

Also, an old video of that bitcrusher I forgot ever existed:

Sunday, January 31, 2010

DIY Synth log #2

Little board I made to help me in developping the programmable synth. Seeing how so many things need to be controlled by DACs (for preset recall and automation), made a little 16-channel multiplexer with sample-and-hold.

Still shopping around for a simple 16-bit DAC. most are either SMD, or are I2S (too slow) instead of SPI. And I can't spare the pins for parallel. Eugh...

Sunday, January 10, 2010

DIY Synth log #1

Some sounds I had lying around:


Part of a long-term project of building a synth. The rough outline is:

-3 or 4 oscillators. sine, square, triangle, ramp
-2 or 3 LFOs for FM, AM and VCF
-1 noise generator
-lots of LFO shapes, including "manual" waveshaping
-resonant VCF (using SSM2044)
-2 ADSRs for amplitude and VCF
-programmable delay (based on 2399)
-savable patches
-real wood enclosure and 2-octave keybed!
-some kind of basic arpeggio/sequencer
-MIDI-in a big maybe. I haven't looked at MIDI yet

I'm using DSI-type synths (evolver, prophet) as inflluence for the design. Digital control of analog stuff! In the sounds above, I'm using a atmega88 microcontroller to drive an MCP4921 DAC which in turn drives an analog XR2206 function generator. The 12-bit resolution of the DAC gives me a range between 30hz to around 8khz with tolerable drift. The micro has a table of all DAC values for 92 notes. The samples are straight from the oscillator. There's no envelope, filter, LFO or anything. The delay in the first one was added in soundforge for kicks. The "sequencing" is hard-coded in the micro.

The XR2206 is basically a voltage-controlled oscillator with sine/triangle/square outputs, and ramp with a bit of tweaking. It's really simple to use and requires almost no external components!

I'm gonna need a lot of DACs. One for each oscillator, for each LFO/ADSR combo. I intend to do the LFOs and ADSRs in code to make them flexible and as low-part-count as possible! I think I can mix both LFO and ADSR in code and have it use just one DAC.

I'm hoping to make the delay as dynamic as possible! Time and decay modulated by keys and LFOs and whatnot! If I can fit all components for a single "voice" (a dozen chips, I'm guessing) i nsmall-enough space, then I might consider making this a 4-voice synth. The main micro would just have to keep track of which voices are available, and if none are, use the one that was pressed the longest time ago.

I don't know yet if I want to salvage a wooden enclosure from something or just make my own. I haven't done any sort of woodworking since when I was a kid. It's not hard, but I am sort of ill-equipped! I'm not worried for the keybed. Doepfer has some nice OEM ones.