Can I just solder this 3.5mm plug cable onto an Audio Adapter Rev D?

Vagabond Elf

New member
Hi, this is a very basic question, but: I need a 3.5mm plug on an Audio Adapter Rev D, to upgrade an existing system (an R2 unit). All the existing audio uses 3.5mm plugs and I'm just trying to replace the old sound generator with one based on the 4.1 and the Rev D.

(None of that is my work, but if you want to see what folks have done with your hardware, here's the project:

https://humancyborgrelations.com/ )

Anyway, after overthinking this for a while it was suggested to just solder a 3.5mm plug onto the Line Out through-holes. Something like this:


MFG_10-03405.jpg

My only concern is that there are two contacts for each of Left and Right on the Rev D board, and only one wire on this cable. Five wire cables don't seem to exist.

Can I just assume that the extra contact is for functionality I don't need, and leave one open? Should I splice both Left contacts to the left wire? Or is this totally a bad idea?

In that last case, what suggestions do people have for getting a 3.5mm plug (or jack, I could make that work too) onto the Rev D.

Thank you all so much!
 
Hi, this is a very basic question, but: I need a 3.5mm plug on an Audio Adapter Rev D, to upgrade an existing system (an R2 unit). All the existing audio uses 3.5mm plugs and I'm just trying to replace the old sound generator with one based on the 4.1 and the Rev D.

(None of that is my work, but if you want to see what folks have done with your hardware, here's the project:

https://humancyborgrelations.com/ )

Anyway, after overthinking this for a while it was suggested to just solder a 3.5mm plug onto the Line Out through-holes. Something like this:


View attachment 36570
My only concern is that there are two contacts for each of Left and Right on the Rev D board, and only one wire on this cable. Five wire cables don't seem to exist.

Can I just assume that the extra contact is for functionality I don't need, and leave one open? Should I splice both Left contacts to the left wire? Or is this totally a bad idea?

In that last case, what suggestions do people have for getting a 3.5mm plug (or jack, I could make that work too) onto the Rev D.

Thank you all so much!
On the audio adapter the pinouts are set up so the 3 pins across are for a combined L/R speaker (i.e. the middle pin is the shared ground between the left and right signals). If you had two separate speakers, then the other two pins would be the ground, i.e. you can connect the speakers separately, each with their own ground pin. Thus for your setup, you can connect using the 3 pins going straight across.

Here is an article I found that goes over the wiring (red is left, black is ground, white is right -- but just in case, you might want to use a multimeter to confirm which wire goes to which connector on the 3.5mm cable (i.e. the tip is left, the center/ring is right, and the base/sleeve is ground):
Just to be clear, if you are using the 5 line-out pins, those pins are not amplified. If your speakers do not have amplification, you probably will need to add amplification between the audio adapter and the 3.5mm cable. If you are using the headphone jack instead of the 5 pins, the output level is adjusted for headphones. I know headphones and line-out have different voltage levels, but I don't remember which is which.
 
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The line connections include inputs and outputs, if you are only using the outputs only three wires is needed to ground and the L/R outputs. If you want to use both the inputs and outputs use two cables each with a 3.5mm plug on the other end.
 
Excellent, thank you both! Yes, there's an amp in the droid, but the line-in on the amp is a 3.5mm socket so I need a 3.5mm plug. And the headphone jack is not implemented in the code - which is, admittedly, a little annoying since it complicates testing, but it's not my code and one can't complain too hard about a complex freeware project, right.
 
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