DIY Mini Bass Synth : Meeblip Anode

by heol

18K15643

Intro: DIY Mini Bass Synth : Meeblip Anode

This is my first instructable on building the award-winning monosynth : meeblip anode, from scratch.

Bellow is a video from musicradar showing you the possibility of this synth.

It is a fully open source hardware bass synth, which is made to give you fat bass sounds, via midi control.

If you want an other quick presentation on it and a sound example of what this device can do, check out the manufacturer site : meeblip.com.

Although you can buy it, i think it is way more interesting to build it yourself as it is an open source synth, (hardware and firmware are on GitHub)

So, let's get started!

STEP 1: A Little Bit of Research

First, let's take a look at the source files,

ALL THE FILES NEEDED ARE ON GITHUB.

I decided to make the circuit on stripboard (or veroboard). I find one website who just shows the stripboard version of the schematics on github : irieelectronics.de.

So thanks a lot to Paul on this website for his stripboard design. I know his files are copyrighted and i do not owned the copyrights, but i just wanted to share his great work with you. So thanks a lot to him for understanding. :)

The first picture is the stripboard layout, with PCB traces cuttouts symbolized by red dots.

For the case, i designed the layout with Boxmaker and then edit it in Photoshop. I provided you the PSD files, feel free to use them as you like. (i can't give you a jpeg copy because instructable compress it too much to see the lines on the layout :( . )

STEP 2: Gathering Components and Materials Needed

B.O.M. : (from irieelectronics.de again) : Bill Of Materials (R12 isn't specified, but it is 100 ohm).

EDIT: Link seams dead, new link for BOM.

I got most of the components from taydaelectronics.com, and two or three things like the 9V wall power plug from Banggood.com

You will need an isp programmer like this one, to upload the firmware to the atmega32.

For the enclosure, i used a sheet of 3mm MDF (wood) from my local hardware store.

STEP 3: Start Soldering !

Prepare the board : First, cut the stripboard with a bit according to the red dots on the layout.

Solder it : You need to install the two wire (+5V & GND) under the atmega32 before soldering it.

Then, solder the components on the stripboard according to the layout and the Bill of materials to know which components are referred to which numbers on the layout (like R2, C7, etc...).

WARNING! There is one error in the stripboard design, the first green jumper wire on the left is connected to BL (x;y) although it should be connected to BK. Make sure you do not fall in the trap.

STEP 4: Firmware Programming

To burn the firmware on the atmega32, you first need to download the firmware folder on GitHub.

You can see detailed instruction on how to do it HERE.

I'm just going to give you the headlines on how to do it with the isp programmer listed before (make sure that the drivers are installed correctly, you can fin useful infos on that by searching on Google.)

Install WinAVR (for windows) (to allow the computer communicate with the atmega trough the programmer) : Link HERE

Open the file "make-anode.bat" in the firmware folder, and change the name after "-C" to the name of your isp programmer. Mine is "usbasp" so here is my file : 

avrdude -c usbasp -p m32 -B 5 -U flash:w:anode.hex -U lfuse:w:0xBF:m -U hfuse:w:0xD9:m pause

I added the command "pause" at the end to prevent the console to close herself after process is done, that way you can see if the process went successfully or failed.

Then connect the programmer to the computer and the pins to their right spot on the stripboard. (black spots left to the atmega, names are in blue on the left on the picture.) Take attention when doing it, if you plug it the wrong way, you may destroy your atmega32 !

Then, run the file "make-anode.bat"

Done ! Firmware flashed on the microcontroler ! :D

(If it fail, make sure that you have the correct drivers installed, the correct isp programmer name, the "firmware" folder with all the others files in it, good connection on your circuit, and the AtMega out of the circuit (put it on a blank breadboard just to program it) and well connected to its 16Mhz crystal on the proper pins.)

STEP 5: Making the Enclosure

I printed the enclosure layout (see PDF layout attachment in step 1 ) and glued them on a sheet of 3mm thick MDF. Then i cut all around the traces and glued the "panels" between them. Don't glue the top one or you wont be able to open it to place electronics in there ! :p

I painted it black after sanding the case.

STEP 6: Mounting the Pots and Wiring Them

First, place the panel-mounted components on the side and wire them according to the layout.

Then, place the pots and switches on the top panel according to the second layout, and wire them to the stripboard.

I added little knobs to the pots.

(Credits : layouts are from irieelectronics.de, i added connections names to the second one for better understanding )

STEP 7: Mounting the Switches and Others Connectors

Mount the switches and the midi jack, the audio jack, the midi-learn button and the DC-power jack.

Then you can wire them according to the layout.

STEP 8: Wiring Everything

This step is a bit messy. I added connectors to the pcb to be able to disconnect the top panel easily.

STEP 9: Time to Make It Pretty !

I printed some design on some labels, then cut and stuck them on the case.

You can download the pdf file if you also want to print it.

STEP 10: Done !

You can now add power (9v) to your synth and connect to your computer via midi. You can use a cheap usb to midi cable (Like this one) but i would better recommand you to buy this better quality one : Miditech midilink.

Thank you for reading ! Hope you liked it, Don't hesitate to ask any questions :)

27 Comments

bakewelder 1 year ago

Greetings! I am attempting to build this but cant get the FW programming bit worked out. WinAVR doesnt like the make-anode file. Seems that the detailed instructions link went poof! Any help is appreciated! Thanks!

MarcosisN 7 years ago

Great idstructable.. buuuut, i can´t get it work, checked it over
and over again.. The Midi Led flashes if sending notes.. but no sound at
all expect from a clicksound on every note, the pots doesn´t change
anything, not even selecting the midi chanel works... the midi button
makes the led flashing.

Anyone could help me out where to look after?

Thanks alot.. hope to make it wobble soon.

jasonsroach 3 years ago

There are some problems with the layout. I had the same problem. Given this was 4 years ago, you may have given up or figured this out. The transistor is the wrong orientation for a 2n3904 from the BOM but correct for bc547 from the schematic. So for a 2n3904 flip it 180 degrees. The right leg of c12 needs to go up one row. R6 goes do a dead end on the layout. Move it to the other side of the jumper in column "D" but keep going between row "K" and "L". Rotate C10 90 degrees so negative leg hits row "K". And don't forget the cut under r15 because I did. Hopefully this helps others.

vbubobuho 4 years ago


Hello! good project thanks for share!! but on the website the links are broken, I have all the materials but I do not know how to do the wiring, back side pcb... could you help me with the instructions?

secret squirrel 5 years ago

A great project but I have two quick questions:
1. The B.O.M. is a broken link. I've asked the site hosting it to fix it but had no response. Where else can I get a copy?
2. What firmware does this use? I've downloaded v2.03 but am unsure if that is the correct one.

Thanks in advance.

heol 5 years ago

Hi thanks!
You're right, link is broken. I updated the link in my instructable in order to access to the BOM anyway. And for the firmware version, you can use the most recent one (v2.03) as the updates are just some enhancement on the software.
Good luck building your own!

secret squirrel 5 years ago

Many thanks for that. I've just ordered the parts so it will be a few weeks before I start construction.

cheers!

derhoi 6 years ago

Hello! Me again! Finally getting around to making this, made a couple simpler synths first to get the hang of it, also I'm building the triode, which is really very similar to the anode! I'm wondering though... Does anyone happen to remember what they did with the Log pot? The BOM says to get 8 10k Lin pots and 1 10k Log pot, but the official schematics for both the triode and the anode show all pots as Linear... I'm assuming the Log pot is for the volume out, but maybe also it's for the filter resonance? Obviously it's pretty easy to figure it out once it's all together and just switch them around if neccesary, but thought i'd ask in case anyone who built this happens to remember! Thanks so much, such a cool project!

ps. here's a pic of my panel so far, i'm mounting it in my weird frankenrack which is based on eurorack specifications! Loving the punk diy vibe, personally :)

derhoi 6 years ago

KalihariH- Yeah, I'm quite sure it's the volume pot, makes sense! Looking closer at the schematics, looks like on the triode the filter resonance is controlled by the digital pot (MCP4151), using the reading taken off the middle pin of the res pot. Hope it goes smoothly for you, gonna hopefully finish wiring mine up today!

KalihariH 6 years ago

I've got the same question -wanted to put it together in the evening so i just guess it's the Volume one. Let's see and maybe somebody will answer us this question^^

jlosada2 6 years ago

HI, very nice instructable, and great explanation.

I have made the anode and it works fine until it get clogged (or something ) and need to be resetted to work again, have you had a similar issue?

I have also tried the triode, with same results, works fine for a while and then just stops or starts to behave in a funny manner.

heol 6 years ago

Hi thank you ! Yes, mine does exactly the same as you issued, I don't know if it's more of a software issue (which I doubt given the fact that the original anode doesn't seems to do that) or a hardware one. Could be some EMI issue maybe, the perfboard PCB surely doesn't help with that.

stmichel 6 years ago

Hello!
Great work from you and Paul!
Is it me or the layout with PCB traces cuttouts symbolized by red dots from Paul and where you cut the strip board (on your 2nd pic) are not at the same?
I'm a bit confused... ;-)
Please let me know.
Cheers!
Michel

heol 6 years ago

Hi Michel!
Thank you for your comment.
You are right, some of the cuttouts are not the same on the 2 pics.
Paul updated his picture on his website by adding licence information and I think he modified the layout a bit around C10. Just follow his up to date version ans you will be fine!

stmichel 6 years ago

Hi heol!
Thank you! I'll send you some pics of my work!

Best,

Michel

derhoi 6 years ago

Hello! Very excited to build this! I'm kinda embarrassed, because I feel I'm missing something obvious, but... I can't find anything on the Atmega32-P anywhere! Is this the same as the Atmega328-PU or similar? I've searched around and can't seem to find anything that explains the differences to me, but I've never worked with Arduino, etc so maybe I'm just overwhelmed.

heol 6 years ago

Hi!
The "official" name is Atmega32A (but you can find it also with à "-P") sorry if this wasn't clear.
It is not the same as the Atmega328-P used in the Arduino Uno, as the main difference between the two is the number of pins. You can easily find the correct one (Atmega32A) on bangood, ebay or Aliexpress, just search for "Atmega32A DIP" (DIP is for the package type, easy to solder on a stripboard.
Don't hesitate to post pictures here if you made this synth!

derhoi 6 years ago

Thank you! That's fantastic, I will definitely post a pic when it's built, gotta order the components online, so it may be a couple weeks! :D

ΑποσυντονισμένοςΠ 7 years ago

Hey Hi!

Really nice work with the Synth, i was wondering if you could replace the switches of SWEEP n LFO section with Tactile switches n led lights?

-thanks in advance

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