Hi there,

I'm pretty new to electronics, other than tinkering with an RPI, and problem solving broken electronics, but I wanted to make something and thought I would try to get a second opinion on if it would work.

On my PC I only have 1 output for the audio equipment I have (line out). I want to be able to switch between my headphones and speakers on my PC. I bought a splitter cable, but found that sound became heavily distorted after prolonged use (I imagine it's because the speakers are powered, and the headphones are not), so now I'm thinking of making some kind of audio switcher. I checked online and they are available, but expensive for me.

If I run two female 3.5mm audio jacks to a switch, and then run that to another female 3.5mm jack, which would connect to my pc, would it work? Also, would I be able to mitigate interference by using an aluminum case for it?

Kind regards

 

hi TT,
Welcome to AAC.
I use a two-pole, two-way toggle switch, mounted on a small plastic box, it works fine headphones and powered speaker inputs,
E

 

hi TT,
You link the connecting cable screens together from the 3 cables together in the box.

E

 

hi TT,
Welcome to AAC.
I use a two-pole, two-way toggle switch, mounted on a small plastic box, it works fine headphones and powered speaker inputs,
E

I have a toggle switch which I bought today. I'm hoping this will do the job. (I probably should have checked online before buying anything, but really want to make this happen!)

 

Hi TT,
Thats OK, same type I have used.
If you need a wiring diagram, just ask.
E

 

Hi TT,
Thats OK, same type I have used.
If you need a wiring diagram, just ask.
E

Thanks! I will give it a shot using the pinout information that came with the switch and perhaps fail miserably, but I will give it a shot nonetheless. Thanks a lot for boosting my confidence - think that's all I needed

 

You said you have a "line out" but not a "headphones out". A switch will not fix the distortion caused by overloading the line output.
A line output is overloaded if you connect headphones to it. A headphones output has an amplifier driving them.
My pc speakers are powered and have a headphone output on them. When I plug in the headphones then they use the speakers amplifiers.

 

On my PC I only have 1 output for the audio equipment I have (line out).

It would appear you need a headphone amp as well. The left and right channels on the Line-Out jack would connect to the switch with one side going the speaker amp and the other side to the headphone amp. Another possible option would be a modification on the speaker amp where the output from the amp is switch between the speakers and headphones.

The colors shown are for illustrative purposes only.

 

Thanks for the replies! Sorry, I was not clear in my initial post. My soundcard line out is also a headphone out with a 600ohm amplifier built into the soundcard (Soundblaster Audigy RX), my speakers are powered, but also use a 3.5mm jack, hence why I want to make an audio switch. So I'm guessing I don't need an amp?

I've actually worked out that my problem with distortion was not related to the splitter cable after all, but a software issue. I'm still eager to make an audio switcher though, and have already made (or more accurately, repurposed) a housing for it, from an old ac/dc plug adapter.

One question I do have though, is about wire guage. I have some unused 30awg cable. Would this be okay to use in such a project, or would I need to drop to a lower awg?

You said you have a "line out" but not a "headphones out". A switch will not fix the distortion caused by overloading the line output.
A line output is overloaded if you connect headphones to it. A headphones output has an amplifier driving them.
My pc speakers are powered and have a headphone output on them. When I plug in the headphones then they use the speakers amplifiers.

It would appear you need a headphone amp as well. The left and right channels on the Line-Out jack would connect to the switch with one side going the speaker amp and the other side to the headphone amp. Another possible option would be a modification on the speaker amp where the output from the amp is switch between the speakers and headphones.
View attachment 256141
The colors shown are for illustrative purposes only.

 

I have Sony MDR-7506 headphones which have a 63ohm impedance (I'm not likely to upgrade these any time soon!) and so I'm wondering if the 30awg cable would be suitable or not. The housing I've procured is 55mmx42mmx25mm, so I can't imagine I would be using a lot of cable, but if it affects quality then I'd rather try something lower.

 

30AWG will be fine. It's only handling a small current.

 

I hear two very different complaints, which are distortion and interference. I am thinking that the problem is distortion, which has been mentioned and probably solved. If there is also interference that takes different means to cure it.

 

would I be able to mitigate interference by using an aluminum case for it?

hi.
No interference problem has been reported.

The answer is that an aluminium case is not required, a simple plastic box works just fine.

E

 

There may be an issue with wire size, not electrical but rather a mechanical strength consideration. Most inexpensive very small wire is subject to mechanical failure from use. This was most common in the cables connecting electric guitars to the amplifiers. So that may be a separate concern with headphones, although not immediately. Presently I have two sets of headphones with coiled cords awaiting repairs for that failure mode.

 

There may be an issue with wire size, not electrical but rather a mechanical strength consideration. Most inexpensive very small wire is subject to mechanical failure from use. This was most common in the cables connecting electric guitars to the amplifiers. So that may be a separate concern with headphones, although not immediately. Presently I have two sets of headphones with coiled cords awaiting repairs for that failure mode.

It will all be enclosed, so hopefully that will be okay!


After putting it together, I realised that my soldering iron has gone for a walk somewhere, so while I await the arrival of another one, I thought I'd go through what I thought the wiring would be (based on what I've researched).


The output jack is on the other half of the enclosure annoyingly, but I guess it just mimics the connections from the inputs.

Also, with the sleeve ground connection, should I be just running both inputs directly to the output jack sleeve pin?

 

Hello,

Also connect ALL ground connections together.

Bertus

 

Thanks all! I soldered it up with my 8 year old son, as thought he may enjoy it. It's working great straight off the bat! I didn't realise that the direction the switch is pointed is the direction that turns that particular side off, but not too fussed with that, as all I need for it to do is switch the audio from headphones to speakers. I'll probably leave it as one of many quirks of its design!

Super happy with it!

Thanks a lot

 

If you ever disassemble one of those switches you will understand why the direction closed is the opposite of the direction of the toggle handle. Exactly the opposite of the previous scheme . Much simpler to produce, and fewer parts.

 

hi TT,
I would suggest simple stick on labels, to indicate switch action,
If those wires break, use a heavier gauge wire,

E

 

You could also reverse the switch mounting so that the handle will point towards the connection that is working.