The kxmx_bluemchen - An open source, 4hp, Daisy based Eurorack module

So, huge thanks to @grrrwaaa for bringing the kxmx_bluemchen into Oopsy yesterday.

Just pull the latest update from the github repo, and you’ll have access to the kxmx_bluemchen just like the other hardware.

Obviously, the smaller OLED makes everything a bit more cramped than with the Patch, but it is definitely usable:

kxmx_bluemchen_oopsy

I’m looking forward to seeing what sorts of awesomeness get created with this tool!

Thanks once again to @grrrwaaa :clap:

2 Likes

This is fantastically awesome.

And its in the new Oopsy beta, including Nehcmeulb support too :wink:

2 Likes

Amazing project! Thanks for sharing this!
I’ve been modifying it to accommodate a total of 4 knobs with 4 CVs and 2 gate inputs :slight_smile:

First question: is there a particular reason for using TL084s over 74s?

Second question: I wanted to add an external codec, so I was wondering what’s the best replacement for the AK4556? I see on libDaisy that drivers for both WM8731 and PCM3060 have been written. WM8731 being limited to 48khz atm and not certain what limitations the comments mean to for the PCM3060 in terms of audio.

I’m not a very experienced dev or electronician but i find the daisy seed extremely valuable for learning about MCU programming (this actually led me to start taking online C++ classes at almost 40 haha)

What are Electrosmith’s plans for the daisy without the AK4556?

Sorry if I’m getting a little bit OT here… I know there is a specific thread about codec replacement but I thought this thread would also be a good place to ask because this project might expand and this question might be of interest.

1 Like

Nope, they were in stock when was looking for parts. Prefer TL074s as they have a little better noise performance (on paper at least).

This is more of a question for @shensley, but as far as I am aware the PCM3060 is the codec of choice moving forward.

Sounds interesting, would you like to share what you’ve done already? I’d like to have a look.

1 Like

Hey thanks!

Nope, they were in stock when was looking for parts. Prefer TL074s as they have a little better noise performance (on paper at least).

Cool ok :slight_smile:

This is more of a question for @shensley, but as far as I am aware the PCM3060 is the codec of choice moving forward.

So i presume the driver in libDaisy is working. I’m not sure how to link it, though. But anyway i’ve ditched the external audio idea and used these pins for ADCs now.

Sounds interesting, would you like to share what you’ve done already? I’d like to have a look.

For sure mate! Should i share publicly? Maybe my mods made it unusable haha so maybe better to send you privately until it’s tested?
Just bear in mind that im an absolute noob and still climbing the steep electronics learning curve so you might be horrified at how i’ve added stuff on top of your original schematic haha :sweat_smile:
btw there’s now 7 knobs with 7 CVs instead of the planned 4. I think it could fit in 12HP but haven’t done PCB stuff yet.

I think i’d like to expand on this and use the last pin for more knobs via a multiplexer, it will be limited to lfo rate CV modulations but that’s ok (or just very weird sounding audio rate mods). Just knobs everywhere basically.
But let me know on above about public/private x

2 Likes

Yes, of course! I’m a proponent of sharing publicly, and early in a design process. Especially when it comes to self-learn side projects. I see two important benefits to consider:

  1. If people interact, show interest, offer advice, It will motivate you to keep moving forward, especially when you’ve had a setback.
  2. By documenting your mistakes, and their solutions, you’re implicitly helping other, future “noobs” find answers to their questions for as long as this forum remain accessible and indexed by search engines.

I’d suggest giving your project a name, then make a new thread here and describe what you’d like to accomplish, and how you plan to do so. If you’re unsure of anything, then just say so. The kxmx_bluemchen project started out the same way.

2 Likes

This is what I’m talkin’ about!
An “expander” with additional CV/Gate I/O would be sweet.

1 Like

Sweet ok! I agree with this philosophy :slight_smile:
I’ll set that up tomorrow! ^_-

Hey there!
Great Project, really intersted in a Modul.
How can i order prebuilt modules or PCB’s ?

Cheers

Hi everyone,

I’ve almost exhausted my stash of parts. I have enough for 5 more kxmx_bluemchen (no more nechmeulb) DIY kits/modules in 3u/1u. Unfortunately I’m out of Daisy Seeds, so the last five will have to be BYO Seed. If anyone here is still interested, fill out my registration form, I wont be doing another run any time soon.

edit: They’re all now spoken for, so I’ve disabled the registration form.

Thanks to everyone that got a kit or module, I hope you make something beautiful with it, and if you do/did, please share it!

2 Likes

Thank you @recursinging, this unit is exactly what I wanted for a multi-effect slot in my rack, intended to be my own custom Happy Nerding FX Aid in the 3u size and a “master processor” with Dirt/EQ/Compressor in the 1u.
Here’s the first thing I made, before I re-examined my approach to how to deal with the +/- CV vs Knobs. (which will end up being a “select a parameter to attenuvert” thing)
It’s a quick and dirty Oopsy~ multi-effect that I made to test my build: delay, a reverb with dirt, and a 2-16 stage super adjustable phaser.
More to come!

1 Like

somehow the scroll function doesn’t work, when i have more than 4 gen~ patches on my bluemchen. it scrolls down, but the screen is not following. it works fine, when i have more than 4 parameters that i want to edit. is this a general bug?

I don’t know what the default behavior is on the Patch/Field, but it sounds like it might have to do with the smaller screen dimensions of the bluemchen/nehcmeulb. I’d suggest opening an issue in the Oopsy github repo.

If anyone was dying to run OWL patches on bluemchen, be my guest

Ohh I miss this train !
@recursinging any plan for a new batch ?

That’s awesome, thanks for the port!

Sorry, not in the near future.

1 Like

Bluemchen is working wonderfully so far, thanks a lot @recursinging!

Naïve question: Is it safe to have it powered via the eurorack PSU and connected via USB at the same time, or should the rack better be off?

Cheers!

It certainly is safe

1 Like

As @antisvin wrote, it is fine to connect your Eurorack power and USB at the same time.

If you’re developing in C++, do yourself a favor and get a STLINK-V3MINI - using that you can flash your seed without needing to press any buttons, and you can leave your bluemchen racked.

2 Likes