If I'm about to use 4-operator mode, should i write the KON register on both array? Or the otherwise? And what does FNUM LSB even mean?

Hi All, I found this forum http://midibox.org/forums/topic/21320-mb-6582-panel-check/ and see that some others have done the heavy work of designing PCB panels for the MB-6582. I would like to hopefully be able to get one made as well. Anyone have a source for these?

I tried signing up for an account a couple weeks ago and was waiting for the final approval email, but when I tried logging in to check, i get the message that I've been banned. The contact form is also very generic.

Anyone know of a good Drum machine kit? I would like something that could sync with my modular using a clock in.

Hi guys! Sorry for my english, frenchie here So I shelved out a raspi4b and built Norns on it, but i don't have a shield, just a scarlet 2i2

I just diyed a midi controller with an Arduino and I want to replicate K1/2/3&E1/2/3 behavior with it and I thought that was pure midi mapping but it seems i were wrong.

Unfortunately my keyboard won't allow to do changes in matron's script interface -F1/2/3/4 and arrows work in the menu, so I can navigate- means I'm stuck with default settings when I launch scripts, sad. I can't even reset the script, I have to go in maiden to ;restart... Maybe I'm dumb and I didn't found the way to do it with a keyboard I just managed to plug an old mpk mini and send midi notes/CC to play around (Norns kills... dayum this is so good) but not much luck

Do you know by any chance if there is a midi solution to replicate the shield's encoders/knobs? Many thanks in advance for your insights !

I'm looking to modify a little gadget synth and stick it in a normal size box with large pots, switches and buttons. If I remove the tiny SMD LEDs would wiring a through hole to its place work out? Provided the color is the same? Thanks!!

https://imgur.com/a/r1FHMn8

I am using the above input circuit to send a clock signal from jack "CLK_jk" into Arduino pin "CLK_in". I'd like the Arduino to know when the jack is not in use, so it can create its own clock. I tried to wire the jack's switch lug to a spare arduino input "jack_detect", but the jack_detect pin tends to float when its not grounded (ie when the jack is in use). I can't figure out a pull up or switch arrangement that doesn't effect the "CLK_in" pin.

Do you guys have any examples I could imitate? Any input is appreciated.

If I want to use a microcontroller to control a DCO synth voice, how many output lines do I need per voice? I know I'll need signals for gate, velocity, and frequency. Is there a way to combine gate and velocity into a single line, or do they need separate outputs? What's the most practical approach?

Is transferring audio over 2.54mm flat IDC ribbon cable going to introduce noise? What about if I put a ground on either end or something?

For context the two places I'm thinking to use it are, about 20cm in a plastic casio keyboard - from a PCB (direct solder) to a PCB (using a connector) and from a PCB (main board) to PCB (daughter board with pots/audio in/out) with connectors, maybe only 5cm. Again in a plastic casio where there is a little bit of aluminium cardboard for shielding.

I just find them so neat, and easy to make. I've been using a G clamp and slowly tightening it. I know others use a vice, but this works for me.

Hey All,

Any recommendations for places/parts I can use for the sliding chorus pot on a casio CZ3000? I'm in the UK!

If anyone knows a part number I'd be super grateful

TL;DR: What settings should I set my Rigol DS1054Z to emulate the kind of analog scopes used for vintage service manuals?

I’m a bit of a noob with scopes—haven’t used one in a while—and the last time I did, I just hit "Auto" to tune my Juno, which somehow worked. Now I’ve got a Roland System 100 I’m working on, and I’m trying to follow its service manual ( https://www.synthxl.com/wp-content/uploads/2019/05/Roland-system-100-101-Service-Notes.pdf ). Unfortunately, I’m struggling to get my Rigol DS1054Z to display the expected waveforms.

Here’s what’s happening:

• I see a fuzzy sinewave instead of the expected waveforms.
• To see anything, I have to zoom into the 2mV range (max), but at that point, it almost just looks like noise.

What I’ve tried so far:

• Checked both DC and AC coupling on the probe.
• Switched between 1x and 10x settings on the probe.
• Double-checked my test point connections.
• Connected the probe to multiple test points and verified the ground is attached to the VCO board ground.

For example, on test points where I’m supposed to see a saw waveform, I measure 220mV Vpp (as per the manual), but it doesn’t look like a saw at all—it looks more like a fuzzy sine or just noise. I also feel like the Vpp should be higher, but I’m not sure if my scope settings or something in the circuit is limiting the amplitude.

Some specific adjustments I’m trying to make:

• LFO Waveform Adjustment (Page 19).
• Triangle Waveform Adjustment (Page 23, Step 1c).

What I need help with:

• Should I just hit the "Auto" button like I did with my Juno?
• Are there specific settings I can tweak on the Rigol DS1054Z to mimic the behavior of analog scopes used in these vintage service manuals?
• Could cleaning the test point contacts improve this?

Any advice on how to adapt a modern digital scope for this kind of work would be massively appreciated! Thanks in advance!

This video shows PCM file loading along with tricks of lowering the quality of the playback and modulating them with the built-in single-cycle waveforms.

https://youtu.be/PHGQqivtu94

In a few days, I'll share a presentation of this mess at the Nerves/Elixir meetup.

TL;DR:

BOM Squad (https://bom-squad.com/) is a free, open-source tool I’ve been building for the past three years to make DIY synth-building easier and less frustrating.

Summary of key features (7 minutes): https://youtu.be/ddtQrfLwvgs

It’s still in beta testing, so expect bugs and changes as we improve things. BOM Squad is open-source (Django, React, TypeScript, PostgreSQL, Docker) and perfect for first-time contributors. Check out the GitHub or watch one of the videos for more details:

Wall of text…:

Hey DIY audio hardware folks! Hope you had a great Thanksgiving if you celebrate it!

I’m super excited (and a little nervous) to finally share BOM Squad, a free tool I’ve been slowly and not-so steadily building for the past three years. It’s an open-source web tool I built to solve the frustrations I faced when I got into DIY synth building during the pandemic. If you’ve ever been overwhelmed reading a manufacturer datasheet or remember how hard it was to put together a BOM during the pandemic, this tool is dedicated to you.

Here’s how it started: back in 2020, like a lot of people, I suddenly had a lot more time at home. I decided to dive into DIY audio hardware, starting with Nonlinearcircuits Eurorack modules. I learned to solder, built a few kits, and then rapidly got frustrated by how opaque the whole semiconductor industry felt to me as a beginner.

Every build came with a BOM—a long list of components I needed to source. If I was working on multiple projects, I’d copy everything into a spreadsheet to figure out which components overlapped so I could save on shipping. People share spreadsheets, but it’s the wild west out there, with little standardization of notation. I’d spend hours sorting through supplier websites trying to figure out which ICs to buy, only to find out that some components were out of stock or discontinued, or there were multiple options I didn’t fully understand. On top of that, keeping track of my personal inventory—what I had, where I stored it, and how much was left—was a nightmare.

My background is in software development (I also have two degrees in music), so I started building a tool to make the process easier. After a couple false starts, that tool became BOM Squad. It’s meant to be the kind of thing I wish I’d had when I was starting out: an interactive, community-driven app that simplifies sourcing components, managing inventory, and organizing your builds.

So far I’ve gotten enthusiastic support for both initial users and manufacturers. All manufacturers on the site are there because they wanted their modules listed. I plan to add DIY guitar pedals and other types of DIY audio projects over time.

Here’s what it does:

• Interactive BOMs: Forget static spreadsheets. BOM Squad turns manufacturer BOMs into actionable lists with links to suppliers like Mouser, Tayda, and DigiKey. You can compare components, get recommendations, and even see reviews from other users about what works best for specific builds. If you choose to use the inventory feature, the BOM itself is aware of your inventory and cross checks components against what you already have.
• Inventory Management: You can track your components down to the exact shelf or box (think: “Closet -> Box 6 -> Cell E4”). BOM Squad cross-references your inventory with your BOMs, so you’ll always know what you already have and what you still need. It also logs all changes in Inventory Version History, so you can undo mistakes if needed. And yes, there’s a BIG TEXT and dark mode for late-night soldering sessions. :)
• Quick Export: If you don’t want to use the inventory feature, that’s fine! BOM Squad lets you export BOMs directly into formats compatible with supplier upload tools like Mouser, DigiKey, or TME. So you can create a cart on a supplier website directly from the interactive BOM. This makes it super easy to populate shopping carts and skip the manual entry.
• Custom components and suggestions: You can add your own components to the database if they’re not already listed (this feature is currently in development and is changing fast from day to day). A new feature we’re adding soon is the ability for users to attach suggested components to BOM items. This will make it easier to find substitutes for discontinued parts or get recommendations from other users.
• Consolidated Shopping Lists: If you’re juggling multiple builds, BOM Squad groups all the components you need by supplier, calculates costs, and helps you avoid over-ordering. It even lets you save and reuse shopping lists for recurring builds. 
• Community Knowledge: BOM Squad is designed to be a hub for the DIY synth community. Users can leave comments on components, modules, or builds, sharing insights and tips. You can also see how frequently certain components are used across different projects, which can help with planning and sourcing.

This has been a labor of love for the past three years. I’ve built it in my spare time while balancing a full-time job, a growing family (my wife and I had a daughter during this time!), and my passion for music and coding. BOM Squad is free to use and open-source. If you have a background in software, whether you’re an experienced engineer or new grad, we’d love to have your help with the project over on GitHub. It’s actually the perfect first contribution to open source, because I’m still trying to figure everything out myself. :) It’s built with Django, React, TypeScript, React Query, React Hook Form, Tailwind, PostgreSQL, and Docker, so it’s a great opportunity for anyone looking to get into open-source development.

Feel free to create an account and check it out, but please remember this tool is still in beta test mode! Things will change rapidly for the foreseeable future and there are still lots of bugs and stuff is rough around the edges still. I would love any and all feedback, and bugs can be reported either via opening an issue on GitHub or through the “Report a bug” button you see on some pages of the site.

In case you’re looking to dive deeper, I made a couple videos outlining key features, although the videos are already out of date with regard to the feature set that’s currently there:

Summary of key features (7 minutes): https://youtu.be/ddtQrfLwvgs

Full video: https://youtu.be/7cbePdMJsms

This has been a super rewarding project to work on, including a lot of feedback I’ve already gotten from the Nonlinearcircuits community over on Facebook, and I hope it makes DIY synth-building easier, more fun, and accessible for everyone. Let me know what you think—feedback, feature ideas, or just sharing your experience means the world. Let’s build something amazing together! 🎶

I’m really looking into getting a modular setup and im doing most of it myself. My only concern atp is the power supply. I’ve seen a bunch of people suggest using old PC power supplies like Meanwell’s stuff, and I was wondering if that’s a safe, reliable option. I was looking at this one in particular: https://a.co/d/fJcoUv9 . That should at least cover the +12V/-12V.

Second question, if Meanwells are a good choice, how do I connect it to a busboard so I can actually connect it to modules?

Please lmk if I got anything wrong, I’m definitely still learning.

I had an idea for cv to midi conversion for a drum sampler on the laptop

Instead of continuous cv which might be inaccurate using clock signals to set midi cc values 1-127 or maybe even 14 bit cc so no need for good adc

Just count the period of the clock

Any idea how I would get started with physical components pretty good with software

Hi everyone, quick question here. My knowledge of electrical systems is average, not great, not terrible.

I recently got a Befaco Midi Thing v2 and I tried putting it in a case that does not provide 5v and the module does not power on. However, it does work in a case that provides 5v.

Now, I see that, on the back of the module, is a separate power board that outputs +12v, -7v and twice +5v (see image below). I have measured all outputs while connected and all but the top +5v give off power. So I asume that the top 5v is connected directly to the 5v from the rail, which my case is missing. The bottom +5v gives off 5v, like it should.

Is it ok to just solder a bridge between both +5v's? I quickly tried it out using the pin of my multimeter and the module seems to power up if I do. But I'm not sure if this could cause long term harm.

I'm unsure what the meaning is to have two separate 5v lines...

I *think* that it should be ok to connect them, since it seems that the top 5v line is not connected to anything, it reads 0 on the multimeter. (If it IS connected directly to the 5v rail of the case, it could cause it provide 5v to other modules, but none of my other modules seem to mind missing the 5v rail, so I assume its not that big a deal.)

What do you think?

https://preview.redd.it/kalwowfxqw3e1.png?width=680&format=png&auto=webp&s=6a141f849a1241462b27d8d0c48c0fa222fafbe3

I will be building a modular system in the Kosmo format. In my search for cheap panels I found some old wooden sheets. They are very sturdy, but unfortunately they are quite thick at 6mm. Would this be prohibitively thick? Are there other downsides to wooden panels that I haven't foreseen? My thanks to you.

https://youtu.be/5pM_iNj7izk?si=eTlSK2oTfYp3NIsJ

I am working on a controller for a modular touch keyboard, It has the usual up/down octave switches. The way it is now, you can switch octaves while playing a note, and the note gets "left behind" without a note off. that could be useful in some cases (droning bass note), and you can kill all notes by pressing a button. what is the "normal" logic in that situation?

I've been building Benji Jiao's (u/couchpatata) Misiosc 2 (schematic is here). I'm not getting anything out of it and trying to debug here.

Taking measurements when I have the coarse and fine tuning roughly 1/3rd from the bottom, I'm getting -0.1 V at the base of Q4 (PNP).

I then have 0.4 V at the base of Q3 (NPN).

I'd expect the 40106 to be oscillating but there's nothing on my oscilloscope at TP5 or TP6. I did also check that each of the ICs is getting the correct +/- 12V (or ground for 40106) at the correct pins. Any advice for debugging?

Thanks.

Im looking to get into building my own synth and dont really know what modules I need to start with, any links/schematics would be amazing!!

This is is a really simple question but I need it spelled out for me. I have a Realistic MG-1 and want to integrate a V-trigger to S-trigger converter directly into the Trigger jack. I understand the concept and how to build the converter cable, but am getting lost on how to wire it directly inside my synth instead of a cable. Can anyone help!? A diagram would be ideal.

The Trigger in jack on my MG-1 has a ground at the sleeve and wire at the tip. Thanks in advance!