MidiBox Questions

Design Concepts
1

I’ve been doing a lot a research on midibox, and have decided to start a project. I do have a couple questions.

The main one is about the way buttons work. The main question is are most buttons the same in how they work? The reason I ask is because I want to send mometary CC messages such that they would be on when held down and off when released. This would not be possible afaik if there exist (I ask out of ignorance) buttons that only send signal when pushed for a short time, but do not continue to do so..

My second question is about the midibox mixer project..

From what I understand the midibox mixer is a midibox that would allow midi messages to be sent, as well as input and output audio. (Please correct me if I am wrong)

I am wondering then if it would be possible to create a midibox, and then later add functionality to it and switch to midibox mixer, or is there something in the design process that would not allow it.

Ideally I want to make a midi controller for dj’ing that would have 4 audio channels output (or is mbmixer only ins?) 2 going to my main output, and then 2 going to a stereo output for cueing tracks to headphones.

-Matt

2

Not to sway you from doing it on your own, but this thing looks fantastic and would likely do everything you want (and then some) and probably for the same, if not less, than designing one on your own. Making your own is incredibly fun, but it also takes a lots of work, time, and money.

That said, as far as buttons go, you can control their behavior likely in your DJ software or via the firmware, so no problem there. Have a look at the MIDIO128 page for more explanation. Button behavior is stored in patches so you can have multiple setups for different use-cases (say one patch for Traktor, one for Live, etc.).

For the audio mixer component, the project I think you are referring to is this one. It is a digitally controlled analog mixer so you can control the volume of analog sources digitally (using MIDI), however it does not convert digital audio coming, say, from your computer (it’s not a sound-card). It also uses custom firmware on the now older PIC platform. You may be able to combine it with your control surface, however, but may have to either make custom firmware or use internal MIDI routing features found on the MIDIO128.

3

My second question is about the midibox mixer project..

From what I understand the midibox mixer is a midibox that would allow midi messages to be sent, as well as input and output audio. (Please correct me if I am wrong)

I am wondering then if it would be possible to create a midibox, and then later add functionality to it and switch to midibox mixer, or is there something in the design process that would not allow it.

Ideally I want to make a midi controller for dj’ing that would have 4 audio channels output (or is mbmixer only ins?) 2 going to my main output, and then 2 going to a stereo output for cueing tracks to headphones.

-Matt

The Midibox mixer will mix analog audio, and can be configured for two separate stereo outputs. (one for mains, the other for headphones). It can support up to 16 stereo pairs input.

It should NOT be used as a control surface, it would be far better to use a second core to manage your controls. This would also allow separation of the controls and the audio mix section, as well as the ability to record and play back the mix using any sequencer. I also have control windows using java on a PC, or native code for AmigaOS4. Normally, I have ALL of these methods “in control” at once, with all changes being echoed back to all the various control points. (Amigas are very flexible with MIDI handling)

When I completed the project, SmashTV helped me with a final board re-design, and I had hoped he could carry the boards in his webshop. Unfortunately the economy took a deep dive, and the community has moved on to other core designs.

I still have the original “version 2” mixer as shown in the Wiki, and it still gets used every single day. It’s a very versatile mixer, and it even fits into a 1U case! I promised Smash exclusive access to the board designs, and I haven’t heard from him in a while. I am good to my word, and will not release the board files to anyone else. (besides, he has the better version that we collaborated on, I don’t).

It is great to hear that there is still interest in the project. Though I’m now quite busy doing coding for AmigaOS4, I try to stop by here every day or so.

I am confident that the mixer could be ported easily to any of the other cores, and probably re-written in C as well, without much trouble. It’s actually just a bunch of simple math to create a mixer model.

The future of the project from here would have to start with boards, but if they become available, the code and the original coder will be available. :slight_smile:

LyleHaze

4

it’s not a sound-card

My question answered.

I was also wondering what those potentiometers are called that have that “sweet spot”. The ones that sort of lock to the spot more or less, right in the middle.

5

My question answered.

Now as far as midio128 goes, unless I’m mistaken it appears to limit how many pots you can use quite a bit.. Would I be looking more towards going the midibox64 route?

I was also wondering what those potentiometers are called that have that “sweet spot”. The ones that sort of lock to the spot more or less, right in the middle.

What you want to do is to base what you’re building on the new core (LPC17). Also, you’re looking for center-detent pots. Those are the ones with a slight click/stop in the middle.

/J