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View Full Version : Possible / Easy to Wire One of these up?



Smack2k
May 11th, 2017, 04:27 PM
Is it easy / possible to wire one of these up if I already have the male audio input cables and a female output cable? The cables would come from three different places / other cables.

https://images-na.ssl-images-amazon.com/images/I/316WVXufaFL._SY300_.jpg

I know they are cheap, but curious if they are easy to wire up with parts I already have?

Also, could it be used for two line outs on two soundcards installed in the same computer and have it work for whichever is in use at that time during gaming or listening to music?

jamesbeat
May 11th, 2017, 05:36 PM
If you already have two male cables and a female one, it should be pretty simple to put one together yourself, but not necessarily easy.

What I mean by that is that the connections you need to make are easy to figure out, but actually putting that into practice can be difficult.

The wires in these cables are often very thin, and are usually insulated with lacquer.
This makes it tricky (though certainly not impossible by any means) to solder them and to insulate those soldered joints.

The lacquer insulation (or the very thin plastic that is sometimes used) shrinks back from the heat of the soldering iron, so you have to be very careful to insulate everything afterwards.

Another potential problem is strain relief.
Those thin wires can't stand much tugging before they snap.

And talking of strain relief, these cables often have polyester threads intertwined with the (extremely thin) copper conductors to minimise the chance of them breaking.
This thread makes the wires uncooperative - they don't stay where you bend them and they like to untwist themselves when you twist then together.
Heat from the soldering iron will make these threads shrivel away to nothing, which helps a great deal.

I've spliced together many cables similar to this, and the results have always been functional but not pretty.

I think what I'm trying to say is that yes, you most certainly can do it, but given how inexpensive these things are, I don't think it's something I would personally choose to do if it's not an emergency.

For example, we bought our son a new PC a few years ago, and didn't pick up the correct audio cable.
We hooked up his new PC to his TV, but it had no sound.

It turned out that for PC input on his TV, you had to use the 3.5mm audio in, which meant that I needed a cable with 3.5mm plugs at both ends.
I thought I could use the red/white phono connectors, and I had one of those cables already.
That qualified as an emergency, so I ransacked the house for a set of broken headphones to rig him up a cable.

If it could have waited a day, there's no way I would have gone to the trouble.


I actually have to do something similar this weekend.
I'm building a Raspberry Pi into a PC case, so I'm breaking out all the ports to the rear of the machine, where they will be mounted in slot covers.

My panel mount audio jack arrived today, so I have to get a cable, cut one of the ends off and solder it onto the jack.

I'm not particularly looking forward to it. I'm going to try to find the chunkiest audio cable I can - the thicker the conductors, the easier it will be.


As to your other question about plugging your cable into two sound cards, I think I understand what you want to do.
A potential problem is that those cables are wired in parallel, meaning that the output from one audio card will feed into the input on the other, just as if it was a double ended 3.5mm plug.

If that's what you meant, then my gut feeling is that it would not be a good idea, but I don't know enough about it to give you a definitive answer.

zombienerd
May 11th, 2017, 06:00 PM
I've made several of these using old aux cords. I have stolen the headphone jack out of many an old transistor pocket radio, busted CD-ROM drive, or the like.

If you have a soldering iron, it makes it a very quick hack-job. Just use heat shrink (or vinyl tape if you don't care about appearance) over solder joints and you're good to go.

Some aux cords use the braided fabric wires - these rarely work for this application. You want to find cables with standard twisted wire.

smbaker
May 11th, 2017, 08:37 PM
I have done this sort of thing before successfully, but as others have said in this thread, it does depend on the type of cable used and you often don't know that until you cut one of them in half. Some audio cables are easy to work with. Others are downright nasty. It also depends on how nice you want it to look with heatshrink and such. Honestly, I'd just buy the damn thing for $5 unless time was of the essence.

Now, as far as using it to tie together two line outputs from sound cards, I'm not sure that's a good idea as described. I think you want to at least add a couple resistors to "mix" the two audio signals. Even better would be to involve an op-amp in the design (google "summing op-amp"). For a quick and dirty hack, I'd just try the resistors.

Scott

KC9UDX
May 11th, 2017, 09:34 PM
This is where Radio Schack was good 5 years ago.

Smack2k
May 12th, 2017, 01:16 PM
Thanks for all the info!!

If it's gonna cause sound issues I don't want to do it. I am trying to setup an RCA switcher I have to match my kvm as both are 8 ports, so port 3 on the kvm is a pentium 1 and the audio from the P1 matches port 3 on the RCA switch. Seeing as I am only using 7 ports I guess a better option would be to use one port for each soundcard in the system. Was hoping no the two to one solution would work to keep the ports identical on both switches. Either that or swap RCA cables in the port being used in the switcher depending on which card I use....

roberttx
May 12th, 2017, 02:34 PM
This is where Radio Schack was good 5 years ago.

This is why I bought a sizeable chunk of the stock of two* Radio Shacks that closed down near us. When I need something like this and it's not already in one of my adapter drawers, I go the the Rat Shack boxes and (more often than not) I find it.

Of course, that doesn't help when you need a GR-900 adapter (did they ever stock those?) But I have plenty of those from another source.


* We started with six. The two that I bought out were franchises and closed independently-ish of the first round of closures. I say "ish" because the retiring owners would likely have sold them as going concerns, if Radio Shack wasn't circling the drain.

The next two went in the most recent round. I got nothing, because what they couldn't mark up, then pretend to discount and sell they took to the last two stores. You can bet that I'll be hovering like a vulture when they go down for the third time.

MikeS
May 12th, 2017, 03:11 PM
This is where Radio Schack was good 5 years ago.

You can find cables & adapters like this at most Dollar stores...

Smack2k
May 12th, 2017, 04:13 PM
I looked at a couple dollar stores and didn't find any of them

Looks like what I wanted to won't work anyway right? I would have taken each of the two male audio jacks and put them in the outs of each soundcard and then plug the female end into an audio cable that went to the speakers and used the sound from whichever soundcard I was using at the time via the same cable. But that appears to be wrong and not work that way from what others are saying correct?

jamesbeat
May 12th, 2017, 09:16 PM
You can find cables & adapters like this at most Dollar stores...

Look at it again - it's not a standard 'Y' headphone splitter, it's the opposite - one socket and two plugs.

I can't even think what one of these would actually be used for. I don't expect this type of cable is commonly available locally.

MikeS
May 13th, 2017, 10:22 AM
Look at it again - it's not a standard 'Y' headphone splitter, it's the opposite - one socket and two plugs.

I can't even think what one of these would actually be used for. I don't expect this type of cable is commonly available locally.
Probably a mic & earphone to 4-conductor smartphone combo jack, but the plugs should really be red & green.

KC9UDX
May 13th, 2017, 10:43 AM
Look at it again - it's not a standard 'Y' headphone splitter, it's the opposite - one socket and two plugs.

I can't even think what one of these would actually be used for. I don't expect this type of cable is commonly available locally.

I have some. Radio Schack did/does(?) sell them. That was exactly the thing about Radio Schack prior to about 5 years ago. They stocked every configuration of cable, even if it didn't make sense.

KC9UDX
May 13th, 2017, 10:46 AM
Probably a mic & earphone to 4-conductor smartphone combo jack, but the plugs should really be red & green.

One would be mono, and smaller, usually.

MikeS
May 13th, 2017, 01:27 PM
One would be mono, and smaller, usually.
All my headsets have two 3.5mm stereo plugs, one red and the other green or black to match the jacks on my computers; what do you plug into with a mono and smaller plug?

The adapter lets you use a single-plug smartphone headset on your dual-jack laptop/desktop:
https://www.amazon.ca/Insten-Splitter-Smartphone-Headset-Adapter/dp/B00ZH3M5MG/ref=sr_1_5?ie=UTF8&qid=1494699446&sr=8-5&keywords=stereo+y+splitter

Smack2k
May 14th, 2017, 10:20 AM
I am pretty sure that the cable I had listed did the same thing as that above...

Either way, I said f it, and took up two ports on my RCA Switcher for the one PC's sound. I just skipped a port on the KVM to keep the KVM and the RCA Switcher in sync in terms of what is on each port. I only have 7 machines to plug in, so it works out...

zombienerd
May 14th, 2017, 12:16 PM
If you want to go all fancy, I'd bet you could build a manually switched 2-10 port input 1 output box. 3 Pole, 2-10 throw rotary, a handful of 3.5mm females, and a box to toss them in. Then, just use regular patch cables, and you're good to go.

KC9UDX
May 14th, 2017, 09:38 PM
All my headsets have two 3.5mm stereo plugs, one red and the other green or black to match the jacks on my computers; what do you plug into with a mono and smaller plug?

Just about anything transistorised from the 1950s to the present day requiring a headset with a microphone, or anything not specifically requiring that, but where it could be used,. Such as tape recorders and camcorders and things; but mainly two-way radio gear.

The jack spacing is even standardised so that you can use a plug with both connectors.
http://www.repeater-builder.com/yvs/ft-23r/ft-23r-speakermic-plug.gif

The larger one is three-pole in the case of stereo gear. The smaller one can even be three-pole in the case of a REC/PAUSE switch, but that's pretty rare.

MikeS
May 15th, 2017, 07:48 AM
I thought we were talking about computer-related things here, not dictating machines etc.; in my experience cassette recorders etc. (and Tandy and IBM cassette ports) used cables with 3 plugs, where the 2.5mm one was for the remote. What you show is pretty rare and IMO not really relevant to what we're discussing here; desktops and notebooks generally use two separate 3.5mm jacks for mic & 'phone (often with a third one for line-level ), while (non-Apple ;-) ) tablets and smartphones usually use a single 4-conductor jack.

In any case, I think we all agree that simply connecting two audio outputs together is not the best solution and the OP has solved his issue.

Smack2k
May 17th, 2017, 03:47 AM
If you want to go all fancy, I'd bet you could build a manually switched 2-10 port input 1 output box. 3 Pole, 2-10 throw rotary, a handful of 3.5mm females, and a box to toss them in. Then, just use regular patch cables, and you're good to go.

Considering I understand about 50% of the terms used in your explanation....dont think I could pull that off!!!