DX5 Aftertouch Strip

[meener777]

Hi all,

I am looking for a replacement aftertouch strip for a DX5. Its 76 keys length and needs a molex connector like the DX7 strip does. I have been unable to find this part, wondering if anyone can help me locate a suitable replacement?

[madtheory]

I've looked into this a bit because I have the same problem with a 76 note Akai MX-1000. What you have there is a resistive strip. Exposed carbon. Corrodes over time. You can try very gently cleaning it with isopropyl, very carefully, to remove the top layer of oxide. But it will oxidise again after a few years, and then you start loosing actual carbon.

The modern version is a Force Sensitive Resistor such as those made by Ohmite. They are more durable.

In my opinion what you'll need to do is buy several sensor strips, series connect then and solder on your Molex connector. I am planning to do this with my keyboard but have not got around to doing the maths (total resistance, width that fits the keybed, etc.)

[meener777]

Thank you very much for hopping in here this one is really tough for me to get fixed.

So unfortunately I have already tossed out the old one (I kept the molex connector) because I stupidly assumed I had the right replacement part. I bought this piece from Syntaur which someone told me was the same part they used for decades, I didn't realize it didn't have a way to solder the molex connector on until it was too late darn it:
https://syntaur.com/Items.php?Item=1837


The thing is this does not have a connector at all its just carbon on plastic. So one thing I have tried is this adapter, idea i got from a random ancient forum post somewhere:

https://www.amazon.com/gp/product/B074F ... UTF8&psc=1

The thing is I am not sure at all how to do this. I clinched it down and tried plugging it into the synth and running aftertouch test but I'm getting no reading at all, not even 0. By any chance does this make sense as an approach, and if so would you happen to how I might test it incrementally? e.g. if its a resistor then what should the ohms be when its open and when pressure is applied? (I wasn't even sure if it was a resistor lol!)

[Yekuku]

Hi meener , i am afraid you got the wrong connector.
This type of connector looks like it needs metal contacts in order to work.

As you can see from the above picture the FPC cable has metal contacts, your fpc cable has carbon contacts.
Trying to close the connector might damage your Fpc cable.
What you need is this type of connector :

It doesnt matter how many pins the connector has, just use the 2 pins that make contact to the carbon tracks.
The slot in the connector should have the same width as your cable, any pitch would do as long as the middle contact does not short both carbon tracks.

[meener777]

Sorry but the second picture isnt showing up me, looks like a broken link?

[meener777]

Sorry but the second picture isnt showing up me, looks like a broken link?

Okay thats weird if I copy your link into my browser I can see the picture. I think I found the seller on ebay with image search. Ill check my pitch and see what I can find, thank you!

[Yekuku]

For testing you should use a multimeter for reading resistance.
When no pressure is applied the ohm reading should be very high or infinity.
With pressure it should register somewhere between 100 Ohms-1KOhm
Good luck

[meener777]

Cool, part is on order Ill hit you back when I have some results. Really appreciate the help!

[meener777]

You sir are a gentleman and a scholar. With that part I was able to fashion a little adapter and, viola!, the strip works perfectly. Doesnt even need any calibration, out of the box its got a nice sensitivity to it and the clackiness is gone, feels like youre playing on angels pillows.

Thank you for the help!

[Yekuku]

Great work Meener! Enjoy your DX5 !