User Posts

Thonk is now making their own modules!
Here’s the first, a very narrow, but full featured, oscillator/LFO.
Sounds great, and allows you to pull the four waveforms (sine, square, triangle, and saw) off at the same time.
Very easy build, would make a good first kit. Inexpensive too, at this writing (Nov 1, 2024) it’s only 65 pounds.
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Turns out (and I should have noticed this on the other build) that the EBB (which I did last week) and the Flow are IDENTICAL except for the front panel and the microcontroller, you could swap these and get the other unit.
But it deserves its own build guide since you, viewer, might just have the one and searched for that.

Pretty straightforward build, 3-4th kit worthy.
And an interesting LFO in the end, particularly the chaotic waveform it can produce

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A very interesting unit from Befaco, an effects unit that uses multiple swappable cartridges to give you many effects from one module. Comes with 7 carts, which is really cool.

A big build, three circuit boards, tons of components. And one connector, the cart connector, which will challenge your soldering abilities!

Works just fine, and sounds good. Another good one from Befaco.
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A twin Drive/Distortion module. Really easy build, would be a great first kit.
Light bulb housings were a little bit of a pain to mount, but thats a nit-pick.
Sounds good, works very well with a square or saw wave, less distortion with a sine or triangle. And the lights flash!
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A General MIDI synth, complete with full sound banks. Excellent quality samples!
It’s GM, so pretty generic and not tweakable in this unit, so good for backgrounds, pads, and percussion, don’t know if you’ll want to solo any of these.
Can be triggered by CV gate, or by MIDI input, which gives you up to 64 voices of polyphony, quite a large selection in a small package. By using the HOLD function you can get poly sounds with CV, or just trigger them with MIDI.

A simple build, would be a great first kit to give you a solid foundation of sounds for your rig.
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A 16 wave waveform generator. Has delay, repeats, speed internally, all of which can also be changed with CV. Trigger button or CV in.
Also allows you to “stir in” other signals to affect the wave, which produces some very interesting results.

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To quote “The idea behind GOMA was to make an improved version of the classic 3 Attenuator/Attenuverter modules.”
And that’s what it is. Mostly surface mount already installed, pretty simple build.
And it works just fine, very high fidelity between the input and output signals, and it attenuates and reverses the waveform just fine.
Good module.

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A small all-in-one synth from C.H.A.I.R., distributed by Befaco.
Straightforward build, but there are many tight solder points. Marketed as a beginner kit, but I would recommend you do something easier first and do this as 3-4th kit once you have your solder skills increased.

Sounds fine, good external modification inputs. Would be great for a small rack, get many things in one unit, vco, loo, filter.

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A powerful unit, a joystick controlled modifier of CV and audio with filter, reverb, wave modifiers, loopers, and more.
Mostly surface mount pre-installed. However, the buttons are a little tricky to install so take your time, and I had some interference problems with the button tops that I had to add a water to sort out. But in general a good build.
Demo just scratches the surface of this beast, but does give you an idea of the power here. Very good module.

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Another interesting module from Djupviks. A CV mixer with a chaos core to add some interesting spice to your CV signals.

Really simple build, mostly surface mount already installed, a single-session kit.

And very interesting output. Adds some chaos to mod signals, and I actually tried it with a drum module (see demo section) to get some interesting patterns.
If you’re looking to add some random creativity to your mix, give this a try.

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A little unit to listen to your rack or an individual module on the go. Use headphones, or listen to the little speaker it has on board. Handy when you’re setting up for a show, listen to things before you’ve got your whole rig set up.
Mostly surface mount already installed, and the rest is pretty simple to put together, I couldn’t find a build guide, but again, it’s pretty straightforward.

One thing to note: During the demo I found that when you drive the speaker with the volume knob more than 2/3s up the power draw rises from 10-28 milliamps up to a max of a whopping 280 milliamps, which could be a problem if you’re on a tight power budget, just don’t turn it up too much. Headphone does NOT do that, it’s a safe 10-28 mAmp all the way around the dial.

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A utility module from Befaco, a precise voltage source and adder.
Allows you to have a complete voltage range (either -5/+5v or 0-10v) at your fingertips without having to set a power supply or use a keyboard.
Would be very handy for calibrating a module after a build. Also would be a great way to tune an oscillator or multiple oscillators quickly to exactly the same voltages.
I’ll be using this a lot.
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A nice little filter from Befaco, that's also kinda a mixer and sorta vca. Either mix three signals through the filter or take that filter out, and the vac triggers on input audio voltage, that's why I say "kinda".

Pretty straightforward build, though as typical Befaco there are a number of tight solder locations.

Calibration was a breeze, also.

And sounds pretty sweet. Will sit well in many mixes.

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A dual filter with interesting routings, inspired by the Korg MS-20.
Mostly surface mount pre-installed, but since it’s a stack of 4 circuit boards it’s an interesting build.
Lots of sonic possibilities, sounds really interesting. A good kit.
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As usual, an excellent user guide and build guide which will tell you a lot about making electronics for music (or otherwise), go to their web site and download this even if you don’t buy the module, it’s free.

Pretty straightforward build, good 3-4th kit because of some tight soldering.

And it sounds really really good! I tried some non-standard things during the demo and this is a very versatile unit, I’ll be putting this in the main rack.

NOTE: The version 1 (this build) board labeled MAIN1 has a misprint on the orientation of transistor Q5. I spoke with Feedback Mods and he sent me the correction, I point out what needs to be done twice in this video, or ho to the chapter marker listed below.

I also pasted the calibration instructions under the chapter list.
A multi-wave, multi output LFO. A somewhat involved build, since it’s a stack of three circuit boards, but not too difficult, just a lot to do.

And with the transistor in the right orientation it works just fine. A handy expansion LFO.

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A narrow dual VCO, would be very handy in a small rack. And each VCO allows you to pull a square, triangle, and sine wave at the same time for various blending experiments.

Lots of parts to the build, though it’s not difficult. Maybe a third kit.

Sounds interesting worth it.
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A very quick one today,quickest ever, a passive attenuator/mixer from Zlob. Since it’s passive (no power) it’s just some jacks, pots, and three resistors.
Works as you would expect, controls the voltage of the signal, you can pick up each signal or get the sum. Since it’s passive there is some signal loss.
This would be a very handy unit if you’re really squeezed for power in your portable rack, say, since it just takes space, no milliamps.

Fine build. Good first build if you want to get used to soldering eurorack modules.

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A fine random note generator to stimulate your creativity.
VERY easy to build. This would be an ideal first build, quick to make and useful when you’re done.
Only quibble I have is not being able to reset the sequence (as far as I can tell) with CV. But that’s no reason not to get it.
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An amplifier, limiter, and drive from ThreeTom,
A very easy kit to build, mostly surface mount pre-installed.
Works great as an amp and limiter, I did not get a lot of drive out of it, or I was doing it wrong.
But a great unit to adjust a low signal into your mix, could be very handy!

A wave folder/wave shapers with other good stuff.
Straightforward build, but there are a lot of parts.

Sounds great, some interesting things that I didn’t dive into completely, but you’ll have fun with this.
I’ll admit, I like it more on lower notes that higher, but both are good.
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An interesting little module. It uses a passive infrared motion sensor(PIR) to turn off, or on, a signal path.
Probably not something you’ll use a lot but could have unique uses.
BTW, this is apparently a limited production run of 100, and I think they’re sold out.

Build was super easy, barely an inconvenience. But you can learn about PIR sensors!
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A 8 step sequencer from Synthrotek. Has some interesting output routing, and works reasonably well.
It is a wide beast, if you’re tight on rack space you may want to get a narrower one, even if it’s less capable.
Did have some missing parts again, and this time (a week and a half after I emailed) I haven’t heard back from them.
Assembly is straightforward, and it is a fine unit.
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Another EDU module from Erica Synths that I’ve built, this is their Hi Hat version 2,
Moderately difficult build for close component placement and soldering near other components, not a first kit.

It sounds really good, a very nice unit.

And as always with these modules, the manual (which you can download for free without buying the kit) is superior, a great practical guide to electronics for music.
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A recording sequencer, you play notes in, it will play them back. Has rests, glide, etc., and 3 outputs, which you can assign to any of the 8 sequence slots in the machine.
Mostly surface mount pre-installed, so the build is pretty quick. Only issue I had was I needed to file the push-button holes on the front panel to prevent the switch handles from binding, not a big deal.

Pretty good little unit.
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Following up on the two Random Source/Serge filters I did a while ago here’s their resonant equalizer.
Straightforward build, but you MUST look at the build guide, there are some components listed on the circuit board that ARE NOT actually installed.
Sounds good, equalizes as you would expect, and has some crunchy resonance. Only potential drawback is that it is a wide module, if you’re tight for space you might want a narrower eq.

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A waveshaper today. Very fast build, mostly surface mount already installed. Was missing a power header, but I had spares.

Very interesting folds, a nice unit though I didn’t do the Bias function correctly. Well worth it, and a great first kit.

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A trigger manipulator. Feed it one trigger, and it will “burst” output a selectable amount of triggers, with different patterns and intervals. Many other ways to manipulate, divide, or multiply triggers.
Straightforward build, though lots of parts like many Befaco modules.
And an interesting unit, lots to play with!
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Retro game and other bleep and bloop sound module.
Straightforward build, though there was an incorrect part that I had to replace (Synthrotek offered to replace, but I had already ordered a replacement, they offered me a discount on next kit, which was nice).
Fun sounds, not melodic but could be effects or accents in a piece.

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Erica Synths has a series of educational modules for learning about electronic music generation. This is their kick drum version 2.
A very good kit. Easy to build, and sounds good. Would be a fine addition to a rack.
Even if you don’t buy the kit, I recommend you download the user manual, it’s a great practical guide to electronics in music.

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An interesting unit based on a research paper, creates long-period (up to 30 seconds) to audio range oscillations.
Straightforward build, and interesting uses. If you want some chaotic voltage changes, some evolving over a food bit of time, this is a unit for you. I can certainly see it in a drone or background underlay.

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An interesting unit using “new-old” East German germanium transistors to create some unique fuzz effects.
Simple build, but make sure you look carefully at the picture to install the transistors correctly.
And it does what you’d expect, provides some good fuzzy output, with variable feedback and fuzz. Fuzz also has CV input, an LFO sounds good with it.
Great atmospheric effects possibilities.

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A filter based on the 2600 from the seventies and uses the LM3900 Norton opamp chip.
Straightforward kit, would be good 1st or second kit.

And sounds great, good modification options also.
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A random pattern generator with a number of options, also include a classic clock divider. Interestingly has no (zero) control or CV input outside of the clock trigger, wonder why?
Very easy to assemble, and not too few parts, and not too many parts, for a first or second kit.
Works exactly as described, and an interesting unit to add some random rhythm or arpeggiation to your tunes. Probably would be fun to mess with live, too.
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A bass/kick drum module from Herbs and Stones.

Almost all surface mount pre-installed, so very little to the build. Super easy.

Sounds pretty good, and has some interesting CV inputs for main parameters. Also, it uses a ridiculously small amount of power (like 8 milliamps in my test) so would be great for a power-limited skiff,
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Another one from Djupviks Electronik, a broken delay and no-input mixer.
Very simple build, mostly surface mount already installed so you just need to put on jacks and stuff.
Sounds interesting, though I will admit I did not do the demo full justice, go to their site for a better demo
Would be a fine first kit.

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A Euclidian LFO. Uses the Euclidian functions (search for the math if you’re inclined) to add beats between intervals, and in this case has 4 outputs all handling things a little differently. Most similar euclidians just output trigger pulses to run sequencers, this one has modifiable waveforms, which you can use with a seq or much more CV targets.

Simple to use in basic manipulation but has many more waves and other functions that will allow you to go way deep if you want.

Mostly surface mount pre-installed, so a simple build.
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A locking feedback delay based on the Princeton tech delay/echo chip.
A very good build, not too easy, not too hard. And a great sounding unit, I will be abusing the heck out of this one.

Would be a perfect first eurorack kit!

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A multi-purpose module, shaper, VCO, envelope, slewer, and maybe a few more.

Build is straightforward once you figure out the the build guide pictures are for an earlier revision of the board, NOT the 2.0 in the kit. Might be frustrating to a starting builder, folks, update your build guides when you update your kits.

Works OK. Not as aggressive a shaper as some I’ve done, and the VCO is interesting. Does produce nice envelopes. Could be perfect for you.

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A module based on the Yamaha FM voice chip YM2413 included in many game consoles. Modulated voices and a drum kit alternately.
Straightforward build, nothing too unusual.
Sounds OK. I don’t know how I’ll integrate it into the studio, but might be just your taste.

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A versatile VCO/LFO.
Mostly surface mount pre-installed, so an easy build.
VERY simple to calibrate, and seriously accurate across voltage ranges. And the signals are very straight, no jaggies or steps.
Audio range down to multiple seconds between pulses, very useful. Sounds fine, coupling it with a good filter would make it pop a little more. Overall a nice unit.

Build

Very simple one today, a passive 3 input/output mute. But since I'm committed to building every kit on the planet, nothing gets left out.
Very quick build, vid is only 12 minutes long.
Could be very handy when you want to bring things in and out of a mix without having to mess with (and remember) volume settings or whatever. And very narrow at 2 HP, so an easy fit.
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A nice little sequencer from Robaux.
Pretty straightforward build, could be good for a beginner as 3rd or later kit.

Lots of power and options available. You will want to spend time learning the modes and button presses, it’s not too complicated, but you do need to get used to it. Would be great in a performance setting after you’ve practiced with it for an hour or so.
By the way, mostly a single camera build cuz my side camera got confused.

Will be going in my main rack.

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Ginkosynthese Compressor kit build and demo

A diode compressor from GinkoSynthese.
Pretty good build, but not much documentation so not a beginner kit.

Does some interesting compression, and would be a good addition to your audio chain.

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This is an awesome unit! Even better than the VCF-Q.
Another Serge resonant filter from Random Source. Not just an interpretation but licensed from Serge to be as authentic as possible.
VERY important to read the notes in the build guide and notes in the list of materials, there are components included that you usually will not install though you have the option to, read carefully.
Other than that, the build is straightforward.
HIGHLY recommended!

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A Serge resonant filter from Random Source. Not just an interpretation but licensed from Serge to be as authentic as possible.
VERY important to read the notes in the build guide and notes in the list of materials, there are components included that you usually will not install though you have the option to, read carefully.
Other than that, the build is straightforward.
And the unit sounds very good!

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I like this one quite a bit, think you will also. And having a double saves rack space!

A dual filter with self-resonance.
Straightforward build, quite a few parts.

And when done it sounds great, this is a nice unit and since it’s a double will save you rack space with good sound. Recommended.

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A visual voltage level monitor, attenuator, and mixer from Molten Modular in partnership with Befaco.
Two surface mount parts to solder on, but not tough ones. The rest of the build is straightforward, I’d call it an intermediate kit.

The result is visually appealing, and a great way to monitor voltage swings, my demo with an LFO shows how useful I think it would be for that.
All in all a nice kit, the first from Molten, we’ll be looking for more!
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Herbs and Stones took their groove box and made it eurorack capable.
Not much to the build, this is mostly a surface mount kit and all the SMD is already done. So just pots, jacks, and LEDs.

Getting the front panel on was not a breeze, I think they need to look at the height differences between the pots and jacks they use, but in the end it fits.

Long demo section, since I was learning about the unit and the build was so short. The internal clock did not seem to work, but it took external clocking just fine.
OK unit, not sure where I’ll use this.

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