Grains Kit

This complete and easy-to-build DIY kit is one of the cheapest ways to get a voltage controlled oscillator in your modular - now with aluminum panel

This is a full kit set in the Eurorack format.

Availability: Out of stock

Notify me when this product is back in stock:



A DIY eurorack module! This complete and easy-to-build DIY kit is one of the cheapest ways to get a voltage controlled oscillator in your modular. It is based on digital FOF synthesis and sounds completely different than all other oscillators! It can do minimalistic clicks and plops, screaming leads, fat basslines, weird noises or chiptunes.

How it works
Two triangle-shaped grains form the basis of the sound. The sound is converted to a PWM output and routed via an (optional) low-pass filter and a 100uF capacitor to the output – so no external DAC is required. The low-pass filter on the PCB can be bypassed if you want. Bypassing the filter provides more clarity and a slightly louder output but more artifacts in the sound.

Not bored yet?
Here comes more information about the synthesis technique and you will understand why I called this module “Grains”.
The “Grains” is based on FOF synthesis or formant synthesis. FOF synthesis is closely related to synchronous granular synthesis. It uses two simple triangle-shaped grains. The grains are separated by the same amount of time. With granular synthesis, the spacing within the grains radically change the texture that is created. The FOF grains have very little parameters: pitch and decay. In the basic “Grains” code the 2 decay values are fixed to most musical sounding and can not be altered via potentiometers. So only the pitch of the two grains can be altered via pots (or the cv inputs) and the overall grains repetition which provides the pitch of the output.

Specs & Downloads

Specs & Downloads

Manufacturer Ginko Synthese
HP 4
Depth 30mm
+12V 40mA
-12V 40mA
+5V No
Additional Resources Build Guide


Customer Reviews (6)

Great Beginner KitReview by Josh B.
This took less than 30 minutes to put together. I had a hard time getting the code to load to the module (I'm using a Mac running OSX 10.7), but downloaded the older version of the Arduino app (1.0.6) and it loaded on the first try.

The standard firmware works and sounds great, the fact that there are multiple alternate firmwares is a HUGE plus! I'll be building at least one more of these. (Posted on 4/17/2018)
easiest way to get an arduino into your rackReview by matt
i don't know of a more inexpensive way to get an arduino into a eurorack. Like charliehuge pointed out, this thing isn't just an oscillator. There is code available to make it do different things - easily uploadable stuff at,
or you can write your own, or adapt code from other sources. (Posted on 2/22/2017)
Easy and Sounds GreatReview by br1qbat
Cool little module. Easy to build, easy to flash, and Sounds great. Plus it's a osc that you don't have to calibrate! (Posted on 2/17/2017)
Great kitReview by Mike Darrol
Very easy to build, took about an hour. Great way to get into arduino projects. (Posted on 10/3/2016)
Easy Build, Super CustomizableReview by charliehuge
This kit is great for a low-cost tone generator. You can assemble and program it in a couple hours and get right to patching. But what's really great about it is that it's fully programmable; you don't need to limit yourself to the stock firmware. Sequencers, LFOs, EGs, and all manner of fun toys are possible just by writing some code.

The main downside is that it only output 5Vpp, so you'll need to boost to get it up to the level of your other tone generator modules. Not a huge deal in most systems, though. (Posted on 10/2/2016)
Newbie friendly kitReview by isohedra
nice kit, not super complex. good for someone who has maybe built a module before,
or wants to move up from something dead simple and passive to more complicated parts.
it would help to know the labeling on a pcb / how parts should face. there is no step by step
build guide with pictures of each step. this is easy to learn if you don't know it already.

low parts count.
requires a computer to program the teensy. (super easy)

lots of user made code you can load onto this to change it's function completely.
(Posted on 8/13/2016)

Write Your Own Review

You're reviewing: Grains Kit



Other people marked this product with these tags:

Use spaces to separate tags. Use single quotes (') for phrases.