If like me you bought one of the last series of AD modules, you might have trouble with them when booting your system.
They might be a solution: someone designed a power conditioning module to mitigate the issue. But you’ll have to build it yourself.
The designer kindly posted the BOM and board design on GitHub:
Looks like a super easy project! So what do you need help with?
hello
I have no skills at all in soldering, apart repairing jack cables. so SMD looks difficult to me. and I don’t know if it’s a good project to start learning it.
This thing has 6 components on it and I think this would be a great first project as there’s not much to go wrong. The github for the project has the OSH park link to get the PCB and the rest of the parts can be found easily on a number of stockists like digikey or tayda. I will help you work through it if you want to learn how to build, but if you just want a built board I’m sure someone will volunteer.
Thanks for sharing this, I used to have an AD module but it had this issue with my case at the time.
you’re welcome. if you know anyone who struggled with an AD module, feel free to share.
I think this was designed w/ AD modules in mind since WMD manufactured the ADM line
hello
as far as I remember this module doesn’t mitigate the issue with the last AD modules. people tried it and it wasn’t effective.
Oh I guess I misunderstood what the issue is with the AD modules. I thought the slow start adaptor fixed the problem of them not booting up. I was unaware of other issues
yes sadly almost all of the last modules from AD were problematic. you can read more details in the readme.md of the linked github repo:
Background
At one time Audio Damage manufactured and sold a line of Eurorack synthesizer modules which provided a range of unique functions. Many of these modules are based on the STM32F4 series of microcontrollers and suffer from a power sequencing issue that causes the CPU to hang up when powered from some types of power supplies. It doesn’t happen with just any supply, but if you happen to use one that causes the issue it can be quite frustrating.
The problem arises when the -12V rail stabilizes more slowly than the +12V rail - a sneak path through the input buffer op-amps and codec power supply locks up the MCU in a way which cannot be recovered without power cycling. The only way to prevent this without modifying the module is to insert a switch into the +12V rail and hold it off until the -12V rail stabilizes.
I have prototyped a small PCB with the proper circuitry for this which can be added into the power supply cable. The design info is available here if you are able to DIY such things. I do not manufacture or sell these myself.
Yeah, when I had an AD module, the slow start fix didn’t work.