BOM's, build guide and PCB info
Enjoy trouble free builds and improved reliability with our range of high quality PCB's. Braids, Clouds, Yarns, Rings and many more of your favourite DIY Eurorack synth designs.
People come to me after having tried (and failed with) cheap nasty DIY synth PCB's, which can easily delaminate if not handled correctly and are often not properly tested, board defects can make even a perfect soldering job a complete waste of time and money.
We want to give you the best chance of finishing your projects successfully, all these PCB's undergo thorough testing to ensure that they are true to the design files.
What's more, when you buy our PCB's, they come with free email support for your builds.
And, if you're new to SMD soldering, we offer a free SMD practice kit with your first order, contact us when you order if you want one.
These amazingly robust, top quality PCB's are made at factories with high standards of environmental care and employee welfare, I'm a fool for spending so much on these, enjoy it while it lasts!
All PCB's have been rebranded at Olivier's request, tech support is not available from Mutable Instruments or the MI forum. Please contact me instead.
If you're not completely satisfied, You can return these PCB's for any reason within 14 days of purchase for a full refund.
Each modules page has some comments on the PCB's difficulty level.
Start by soldering the power section, this is normally on the last page of the The Eagle schematic file. Some modules like Branches and Grids have everything on one page because there are fewer components, in which case you'll need to solder on the regulator and associated bypass caps, and anything else in the power path. It's also sensible to solder on the voltage references (LM4040).
Make sure you solder parts on the right way round, diodes, IC's, electrolytic caps etc. Strange, sometimes dangerous, things will happen if you don't. Double check the orientation of polarised parts before you solder or reflow, it's easier that way.
The Eagle BRD file has all the orientation info in it (you may need to turn additional layers on to see it), this is often marked on the PCB as well, if in doubt, contact me.
Once you have done this, solder on the power connector and power on. If anything starts smoking, power off!
Use a multimeter to check all your main voltages are correct, plus and minus 12v at the power input, and the right voltages coming out of the regulators and references, and appearing on the power pins of the MCU.
These will be 3.3v or 5v depending on what you're building. 8 bit Atmel (or Microchip as they are now) AVR microcontrollers often work on 5v, 32 bit ST parts work on 3.3v. Common reference voltages are 5v, -5v, 10v or -10v. If an LM4040 is wired up to the -12v rail it is being used to create a negative reference voltage.
You can use the "finger test" to check if you have any short circuits to ground by touching the regulator, if it's very hot then you might have a short (heat doesn't always indicate a short but in combination with other symptoms it might).
It's normal for regulators to get warm when they're powered, but if the regulator is very hot, power off and check the resistance between the power rails and ground on the PCB. If it's incredibly low, in the Ohm range, you probably have at least one short circuit (it should be somewhere between 1k and 2k).
One advantage of using my PCB's is that they are properly tested, so board defects are much less likely than on a cheap nasty PCB. I've heard the tales of woe, believe me, people unsoldering parts one by one to try and find the bad one, then finding a microscopic copper bridge that was causing a strange malfunction, or the guys who had to cut their power rail into 4 sections so they could find the shorts. I do my best to prevent these problems for your building pleasure.
For digital modules, once your voltages are correct, solder on the MCU and associated parts, deflux, check your soldering using a 10x loupe (magnifier), then flash the firmware (I have some pre-compiled binaries and bootloaders for these modules, please contact me if you want them).
The easiest way to flash STM32 parts is to use a genuine STlink V2 and ST's own Windows Software to flash a binary, though some people will tell you that flashing the firmware is an impossible task, a complete novice can do it this way in less than five minutes. There are a lot of fake STLinks online, but buying from well known electronics retailers will ensure a genuine product. You can also use an STM32 discovery board to flash these IC's, though will need to solder a custom cable to do this. The Olimex AVRISP Mk2 is a good ISP for AVR parts, ISP is short for in sytem programmer.
If you're interested in modifying the code for your module, the Mutable Dev Environment is the easiest way to install everything you need, this uses a Vagrant based virtual machine, pre-installed with most of the relevant software, all pre-configured and ready to go.
If you're hand soldering, the best way to solder fine pitch IC's like the MCU's and codecs is to use a technique called drag soldering. Briefly, instead of trying to solder each pin individually, two corner pins on the IC are soldered down first to keep it in position, then flux is added to all the pins on one side, before molten solder is dragged across them. The flux ensures that the solder flows well, the solder sticks to the unmasked pads, and the solder mask on the PCB helps prevent bridging. Small bridges are common when drag soldering, but are easily wiped away by brushing with a hot iron, or with desoldering braid in some cases.
Once you've flashed the firmware successfully, solder the rest of the SMD parts.
For analogue modules, don't worry about this, they don't have firmware, just solder all the SMD parts.
Clean and deflux, if you don't deflux, strange things may happen (rosin flux can be slightly conductive, you can sidestep this by using a solder with rosin free flux in, this is also better for your health).
After you've defluxed, check for solder bridges again using your 10x loupe.
You can power on again now, and apply the finger test to the regulators.
Once you're happy, and everything is clean, solder on the rest of the through hole parts (pots and jacks mainly), you'll have needed to solder on the power connector already to have powered up the board.
Deflux again (unless you've used solder with no-clean flux for the through hole stuff), then power on and test, all being well, you now have a working module!
Preventative troubleshooting is the best.
If you've properly soldered fully functional parts of the right values in the right places the right way round without any bridges (excess solder connecting points that shouldn't be connected), and flashed the right version of a correctly compiled bootloader and firmware to your MCU, then you'll have a working module.
If it's not working those are the first things to check.
To reduce the possibility of a faulty or counterfeit part causing problems, it's worth buying your parts from a quality source, and good quality PCB's I might add, and paying careful attention to your builds, not rushing, and not soldering when very tired or distracted.
On "reflowing", some people do this, melt all the solder joints in the hopes it'll solve the problem, generally I'd recommend only reflowing relevant joints if there's a problem, and putting a dab of flux on the solder before you remelt it, often mysterious errors can be resolved by reflowing the pins on the STM IC, but check your joints carefully before you do this to avoid unneccessary overheating.
Most troubleshooting boils down to noticing something is not working, then looking for the cause of malfunction and fixing it. A multimeter is an essential troubleshooting tool, an oscilloscope can also come in handy, easiest however is to do it properly in the first place.
Please contact me if you have any questions.
These are Mouser carts to make ordering parts easy, these carts do not include pots (and knobs), 3.5mm audio sockets or the V2164 quad VCA IC's, as these are not available from Mouser. Full BOM's can be found in the Mutable Instruments Github repository. If you need any other files, please contact me. PCB's can be ordered to your right, further info on each to your left (and up a bit).