Sound Lab Builders! Check out the MFOS Mini-Controller.

RF · Posted: Tue Nov 25, 2008 4:06 pm Post subject:

Dang.
You are not measuring a short - or nearly so.... which is what I was expecting.

When you have the batteries hooked up - what are you measuring for voltage + and -?
Then put a MA meter in series with the + supply - what are you measuring for current? Do the same for the - supply.

Back to troubleshooting 101.
Get back in there with a magnifying glass and look for solder bridges. Double check your 'flying wires' to the jacks.
Re-check the IC orientation (they don't all face the same way)

Keep posting what you are finding... and maybe post a nice close shot of the board - top and bottom.

Keep at it.

bruce

Chrometuna · Posted: Tue Nov 25, 2008 5:29 pm Post subject:

RF · Posted: Tue Nov 25, 2008 5:59 pm Post subject:

Awesome!

Congrats on a job well done!
Sometimes it turns out to be the stuff you KNOW you did right!

bruce

Chrometuna

OK, now that I've got the mini-controller basically working, how do I make it work?

(I'm in the process of making a video that might help to explain things better)

Part of the master plan is to make a bass act as a keyboard/controller.

On the mini-controller, there are spots on the PCB for hooking up an external keyboard. So thats where I thought I'd hook in my bass "Keyboard" (Resistor chain running under the fretboard connecting frets, and the string acting as the bus)

I am using a standard XLR sockets and cable because it has three leads: Bus, Key top and key bottom.
I connected those into the "KBTP" and "KBUS" and what I am assuming is "key board bottom" on the PCB.

NOW the weirdness begins:
Without the bass/keyboard plugged in, this opperate normally as far as the key-pads and wand on the mini-controller go. You can hear the different notes from one pad to the next.

BUT
When I plug in my bass/keyboard, then it will trigger, but there are no "Notes" just the same note no matter what pad I hit with the wand. The bass behaves this way too.

I hope I am making some kind of sense here.
Unplugged=Different notes
Plugged in= No different notes.

Should I somehow disconnect the built-in keyboard on the mini-controller if I am going to use an external keyboard?

I'll try to get this video up that might explain the issues better.

RF · Posted: Wed Nov 26, 2008 6:52 pm Post subject:

Looks like the KBD bottom just connects to ground...

Chrometuna · Posted: Thu Nov 27, 2008 12:19 am Post subject:

Chrometuna · Posted: Thu Nov 27, 2008 2:17 pm Post subject:

This video might explain my current problem better then I can describe it.

RF · Posted: Fri Nov 28, 2008 6:18 am Post subject:

Hey Crometuna,
Try lifting one of the legs of a 100 ohm resistor in the resistor chain of the mini-controller, and then try your bass controller.

bruce

Chrometuna · Posted: Fri Nov 28, 2008 2:45 pm Post subject:

RF · Posted: Mon Dec 08, 2008 11:20 am Post subject:

Did you ever get this working Chrometuna?

bruce

Chrometuna · Posted: Wed Dec 10, 2008 7:53 am Post subject:

senkun · Joined: Feb 25, 2009 Posts: 9 Location: TPE