help moding MPD24 - parts

[mekonca]

I want to replace useless 360 encoders on AKAI MPD24 with some regular potentiometer. Is it possible? If yes which I should buy? Here is the picture of MPD24 PCB and encoders have 4 pins in front and 2 a side:

And I would like to change faders with longer one, 10cm. Again which should I buy?

here is the picture of the original faders:

Thank you for any info

[bilderbuchi]

in short: no it's not possible to replace the encoders with pots, it's a totally different technology. pots are effectively axial faders (i.e. a variable resistor), while encoders close contacts for a short time when you turn, depending on turning direction.

[mekonca]

Can I buy some encoder that will behave like pot, just to go from 0-127 "clicks", and not to be 360 degree because I dont need to spin them around and around and around?

Edited July 21, 2011 by mekonca

[Imp]

There are absolute encoders available, but they are expensive and It wouldn't be possible to interface those to the MPD

You could build a mb64 and use real pots though.

[mekonca]

thank you for advice but I was hoping not to build it from scratch :(

Can you tell me anything about FADERS, please?

[Imp]

As bilderbuchi said, they are quite similar to pots.

There are different types, like

-single or dual: dual is like 2xsingle, but only one handle

-linear or logarithmic: determines the curve of the resistance

-length

-resistance

The one in your picture is a 10kOhm log dual, AFAIK.

But this doesn't mean that those inside the mpd have these values too.

Check if you find anything printed on them, if not, you have to measure their resistance.

How do you plan to fit longer faders in there anyway?

They won't fit into the holes of the pcb.

Also, you'd have to build a new enclosure for the whole thing.

[mekonca]

I will built everything on top of MPD24.

I think it will be easy, just wanted to be sure about encoders because MPD24 firmware only accept absolute values from encoders and they are useless, so no relative or incremental data from them. they are sending values from 6 o'clock to 18 o'clock, so 180degresse(and when I pass that 180 in any direction they are not sending anything in any direction, below 0 or above 127, but you can spin them as long as you wish)and I hope that there is some absolute encoder that will imitate EQ POTs from mixers.

I dont need PADS so I will be replacing it with buttons, and MMC buttons on bottom can send MIDI too so I will have 16+5 buttons.

Basically I just want to rearrange it and do something about those useless encoders(but now I see I only can move them :(

Edited July 22, 2011 by mekonca

[Hawkeye]

Just a suggestion, with all that modding around, it might really be easier to sell the MPD24 unmodded and build a new MIDIbox from scratch.

Greets,

Peter

Edited July 22, 2011 by Hawkeye

[mekonca]

Yes but I have here 30 presets and midi IN and OUT for connecting another devices, and I dont have to build whole BOX.

I dont know to program midibox(probably pots and faders will be easy), but how to make led rings for incremental encoders, and 360 degree encoders for jogwheel is a liitle complicated. I found some stuff on this forum and will read it.

Edited July 22, 2011 by mekonca

[mekonca]

Ive read it and there is no led rings, let say, tutorial. Am I skipping some text on this forum or no one right something similar for rookies. A lots of people need that tutorial about led rings, 360 encoders...

[Hawkeye]

The MB64E supports LED rings, for example (Core8 platform).

Also, you can create LED rings using the Core32 platform - tutorial #9.

Edited July 24, 2011 by Hawkeye