Help, problem making a 4 pin DIN power supply for my electronic piano

Thread Starter

wezzdc

Joined Oct 12, 2019
12
Hello, recently bought an old electronic keyboard but it does not come with the power adapter.

Went online to buy but they are crazy expensive so I thought I could save money and buy the parts to make one.

The one available online that is meant for my keyboard, OEM version.
https://www.amazon.com/power-adapter-keyboard-Power-Payless/dp/B01M6ZN4M0

The items I have
  • -an old power adapter with same specs (9v,3A) as the one above
  • -the 4 pin DIN male connector

My plan
  • To cut the power adapter head, then replace it with the 4 pin DIN male connector

The problem I am having
  • The power adapter head wires are only the red(live) and black(earth wire), but the DIN connector has 4 pin outs. How am I supposed to wire these 2 things properly? I did not realize this until I got all the items together. I have looked online for pinout instructions for my keyboard(Korg LE76) but to no avail.

Any help would be amazing.
 

djsfantasi

Joined Apr 11, 2010
5,473
Hello, recently bought an old electronic keyboard but it does not come with the power adapter.

Went online to buy but they are crazy expensive so I thought I could save money and buy the parts to make one.

The one available online that is meant for my keyboard, OEM version.
https://www.amazon.com/power-adapter-keyboard-Power-Payless/dp/B01M6ZN4M0

The items I have
  • -an old power adapter with same specs (9v,3A) as the one above
  • -the 4 pin DIN male connector

My plan
  • To cut the power adapter head, then replace it with the 4 pin DIN male connector

The problem I am having
  • The power adapter head wires are only the red(live) and black(earth wire), but the DIN connector has 4 pin outs. How am I supposed to wire these 2 things properly? I did not realize this until I got all the items together. I have looked online for pinout instructions for my keyboard(Korg LE76) but to no avail.

Any help would be amazing.
You cut off the old adapter, right? If you still have it (I’d have kept it until a new connector was wired), you can pin out all connections with a DMM and the old connector.
 

Thread Starter

wezzdc

Joined Oct 12, 2019
12
You cut off the old adapter, right? If you still have it (I’d have kept it until a new connector was wired), you can pin out all connections with a DMM and the old connector.
I do not have the old adapter! So I have no base of reference how of the 4 pin DIN power adapter is supposed to be wired.

Those power adapters online dont provide any specifications either on the pin out for their 4 pin DIN power adapter.

All I have is my power adapter and the 4pin DIN male connector.
 

ericgibbs

Joined Jan 29, 2010
8,583
hi,
Find this clip from the datasheet, does it compare with the DIN you have.?
E

BTW: Is the old adaptor you have 9V AC [ ie; not DC ]

AAA 004 17.52.gif
 

djsfantasi

Joined Apr 11, 2010
5,473
Can you contact the manufacturer? Or since the link was to an Amazon listing, perhaps you could ask how the DIN adapter pins wired on the “Customer Q&A” page for the item?
 

Thread Starter

wezzdc

Joined Oct 12, 2019
12
hi,
Find this clip from the datasheet, does it compare with the DIN you have.?
E

BTW: Is the old adaptor you have 9V AC [ ie; not DC ]

View attachment 187897
Yes that is the same DIN connector, let me show you with pictures exactly what I am working with.

Can I convert this normal power adapter head to the 4 pin DIN connector? If yes, am I missing any other component? or what should I be looking at.
 

Attachments

Thread Starter

wezzdc

Joined Oct 12, 2019
12
Can you contact the manufacturer? Or since the link was to an Amazon listing, perhaps you could ask how the DIN adapter pins wired on the “Customer Q&A” page for the item?
That is true, I shall do that. I was thinking that they wouldnt know themselves or take too long to reply. So I am still hoping to figure it out thru the help of the internet and this community :)
 

ericgibbs

Joined Jan 29, 2010
8,583
hi,
That power supply you posted is 9V DC at 4A, it is NOT suitable.
E
Update:
This the Genuine part
9V AC Power Adapter Works with KORG TR61 Keyboard

photo6129715374699162566.jpg
 

Thread Starter

wezzdc

Joined Oct 12, 2019
12
I found this from a supplier selling laptop AC adapters with 4 pin dins. The pinout is as attached below in the picture.

Does that mean the connection is just the live wire to both positive poles and the ground wire to both negative poles?

I am worried I am oversimplifying the AC adapter needed for my keyboard as I do not want to damage it.
 

Attachments

ericgibbs

Joined Jan 29, 2010
8,583
hi wezz,
As the power supply is a 9V AC output on two wires, either wire can go to 1 & 2 and the other wire to 3 & 4.

The unit requires an 9V AC supply so that it can generate both Positive and Negative DC voltages for the internal circuits, ref the attached image.

If you are in any doubt about the wiring, visually check the back wiring of the panel mounted 4 pin DIN socket and compare it with this image wiring.

E
 

Attachments

Thread Starter

wezzdc

Joined Oct 12, 2019
12
hi wezz,
As the power supply is a 9V AC output on two wires, either wire can go to 1 & 2 and the other wire to 3 & 4.

The unit requires an 9V AC supply so that it can generate both Positive and Negative DC voltages for the internal circuits, ref the attached image.

If you are in any doubt about the wiring, visually check the back wiring of the panel mounted 4 pin DIN socket and compare it with this image wiring.

E
Can you correct me if I am wrong? Judging from the schematics, it seems the DIN connector, 3,4 are for the positive and the 1,2 for the negative
 

ericgibbs

Joined Jan 29, 2010
8,583
hi,
There is no Pos or Neg wire designation on a 9V AC power supply output.
The internal diodes of the unit Rectify the AC signal to give a +Vdc and a -Vdc voltage, the inputs to the diodes can be connected to either pair of DIN pins.
The DIN pins are NOT electrically polarised.
E
 

bertus

Joined Apr 5, 2008
19,944
Hello,

As @ericgibbs said, you can not connect a DC powersupply to the piano.
There are positive and negative voltages made from the AC inside the piano.
You MUST use an AC adapter to get the piano to work.

Bertus
 

Thread Starter

wezzdc

Joined Oct 12, 2019
12
hi,
There is no Pos or Neg wire designation on a 9V AC power supply output.
The internal diodes of the unit Rectify the AC signal to give a +Vdc and a -Vdc voltage, the inputs to the diodes can be connected to either pair of DIN pins.
The DIN pins are NOT electrically polarised.
E
So what does that mean for my ac adapter and 4pin din connector? Is there a way to add the 4pin din connector to it?
 

Thread Starter

wezzdc

Joined Oct 12, 2019
12
Hello,

As @ericgibbs said, you can not connect a DC powersupply to the piano.
There are positive and negative voltages made from the AC inside the piano.
You MUST use an AC adapter to get the piano to work.

Bertus
Yes understood, I will use an AC adapter. My remaining questions are about how to connect the ac adapter to a 4pin din connection or if that is even possible.
 

ericgibbs

Joined Jan 29, 2010
8,583
My remaining questions are about how to connect the ac adapter to a 4pin din connection or if that is even possible.
Buy a 4 pin mating DIN connector, that fits into the piano mounted DIN.
Is it this type.???
41xv4645BqL._SX425_.jpg
 

Thread Starter

wezzdc

Joined Oct 12, 2019
12
Buy a 4 pin mating DIN connector, that fits into the piano mounted DIN.
Is it this type.???
View attachment 187929
Yes that is exactly what I have, I attached a picture of it a few comments ago.

Now what's left is to solder the ac adapter wires into the 4 pin din male connector.

Not sure what is the right connection and I do not want to damage my keyboard, could you help with this?
 
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