Headphone jack wiring problem

[blind_dado]

I have a female headphone jack on the front of my cabinet that has a wire with a male jack on the end that I plug into the computer inside of the cabinet.  The problem is that when I plug it in to the computer, all sound is diverted to the jack.  What I would like is to still hear the sound through the speakers until I plug in the headphones into the jack on the front of the cab. Does anyone have any ideas on how I could get this to work?

[Kevin Mullins]

Sounds like the jack in the pc would have to be wired differently.... kinda like having a normally open or normally closed switch. The jack in the pc is currently designed to be normally closed allowing the audio to run through the pc outputs, once you plug a headphone jack in there of any kind it opens that connection and diverts it all to the headphones. You would need the pc jack to remain closed with something plugged into it, but then have the one on the outside of the cab open when something is plugged into it.

Or something like that.... I'd have to poke at one a bit to describe it any better.

[blind_dado]

Yeah, I figured out what I would need conceptually, but I'm just wondering if anyone has confronted this issue and has some practical advice.  I know that Mountain has a headphone jack in his admin panel (see link below), but he doesn't explain how he wired it (but maybe he or someone else will have some ideas). 

http://forum.arcadecontrols.com/index.php?topic=63629.msg668652#msg668652

[AcidArmitage]

well wouldnt the headphone extension connection be open until you plug the actual headphones into it? The headphone extension shouldn't close the circuit

[Master15]

Not sure if this is something you'd want to do, but ripping the jack from the front of your pc and mounting it directly to your cab (and extending the wire obviously) should work. Shouldnt be more then a few screw holding the plastic piece into the case.

Other more complicated option probably exist (such has modifying your headphone cable extention with a normally closed female jack)

There is also the option of disabling front jack detection in your Soundcard driver configuration tool (so sound doesnt ever turn off when something is plugged in the jack), and adding a switch or button or whatever to turn off the sound coming out of your speakers, when you do decide to use your headphone.

[Kevin Mullins]

well wouldnt the headphone extension connection be open until you plug the actual headphones into it? The headphone extension shouldn't close the circuit

The problem is the PC jack is still doing what it was designed to do when something is plugged into that jack.

[Zebidee]

Read this guide I wrote on how to do cab audio with volume pots.

http://scarvell.net/wiki/index.php?title=VOLUME_CONTROL_MOUNTING_AND_WIRING

I usually also put in audio jacks with my setups. Audio signal goes from PC -> volume pot -> jack -> speakers.   The jack will cut sound only when something is plugged into it, which is what people normally want.

Use the rear audio jack of your PC, as use of the front jacks sometimes cuts the signal to speakers (I've never seen the rear jack do this?).  If all else fails you can hack directly into the motherboard audio header.

[daywane]

I have a set of speakers that have a headphone jack built in them.
the sound still comes out speakers also

[Kevin Mullins]

Use the rear audio jack of your PC, as use of the front jacks sometimes cuts the signal to speakers (I've never seen the rear jack do this?). 

If you stop and think about it any of the rear ports are designed for you to plug something directly into it and for that something to have all the audio going straight to whatever that may be. (speakers, amplifier, etc)
So if you plug say headphones into one of those jacks.... all the audio will be going to just the headphones. Nothing to the cabinet speakers. You can't just plug them into two different ports, like audio out and line out, because that would obviously defeat the purpose, they would both be on all the time.

I think what you'll want to do is "split" the audio from the audio out port kinda like a Y fashion. Using the headphone jack as a switch per say going to the cabinet speakers and such. So say you take the negative side of the "cabinet" audio and wire the headphone jack so that it makes or breaks that connection depending on whether headphones are plugged in or not. (makes with no headphones - breaks with headphones)

[Kevin Mullins]

I have a set of speakers that have a headphone jack built in them.
the sound still comes out speakers also

That makes no sense then..... in other words it kinda defeats the purpose.
Are you using true stereo headphones or just cheapo mono headphones?
Stereo has three silver sections, mono has two.
Sometimes if you plug the wrong one into the wrong type of jack (i.e. a stereo or mono jack) then weird stuff like that may happen.

[Zebidee]

Use the rear audio jack of your PC, as use of the front jacks sometimes cuts the signal to speakers (I've never seen the rear jack do this?). 

If you stop and think about it any of the rear ports are designed for you to plug something directly into it and for that something to have all the audio going straight to whatever that may be. (speakers, amplifier, etc)
So if you plug say headphones into one of those jacks.... all the audio will be going to just the headphones. Nothing to the cabinet speakers. You can't just plug them into two different ports, like audio out and line out, because that would obviously defeat the purpose, they would both be on all the time.

I think what you'll want to do is "split" the audio from the audio out port kinda like a Y fashion. Using the headphone jack as a switch per say going to the cabinet speakers and such. So say you take the negative side of the "cabinet" audio and wire the headphone jack so that it makes or breaks that connection depending on whether headphones are plugged in or not. (makes with no headphones - breaks with headphones)

I think that Y splitting your audio signal like this is a bad idea. You would make a bunch of problems. You should (generally) aim to have the audio signal pass through each component in series, and this is good practice in electronic circuit design. This is the only best way to properly control where the signal goes and what strength it is.

As the OP said, he wants to be able to get the audio working to the speakers until a headset is plugged into the jack. Not many people want audio coming out of speakers at the same time as it comes out of the headset. If the OP really wants both cab speakers and headphones going at the same time then all they will have to do is create a "bridge" for the ground signal, so that it can get past the jack.

Every headphone jack is different and they can be wired differently. You should make sure that you know how yours works before installing it. However, when wired properly, most will cut the ground signal from anything further down the audio line (i.e. your speakers).

I've done this many times so have a look at the guide (link above). Basically, use a series/linear (component to component) wiring plan. The audio jack should go after the volume control (if you have one), so that you can control the volume for both speakers and headphones.

[Kevin Mullins]

I think that Y splitting your audio signal like this is a bad idea. You would make a bunch of problems. You should (generally) aim to have the audio signal pass through each component in series

Yes, this is also what I was meaning by "Y". Different terminology same result.
Would look much like your potentiometer drawing. Except where there you have a pot there would be a headphone jack. I should have chosen my wording better. (split, Y, etc)

As the OP said, he wants to be able to get the audio working to the speakers until a headset is plugged into the jack.

That was one of my points as well........

Every headphone jack is different and they can be wired differently. You should make sure that you know how yours works before installing it.

Which is also why I wasn't trying to go into specifics about the actual wiring of the jack itself, only the principal.

I've done this many times so have a look at the guide (link above).

Sorry, but I found no information about a phono jack of any sorts there.
I did however totally understand everything I did find there, thanks.

The audio jack should go after the volume control (if you have one), so that you can control the volume for both speakers and headphones.

Good point. I didn't think to ask if they planned on even having an external volume control or if they were just gonna use the software controls.

 

I hope somebody makes some use of the confusion. 

[daywane]

I have a set of speakers that have a headphone jack built in them.
the sound still comes out speakers also

That makes no sense then..... in other words it kinda defeats the purpose.
Are you using true stereo headphones or just cheapo mono headphones?
Stereo has three silver sections, mono has two.
Sometimes if you plug the wrong one into the wrong type of jack (i.e. a stereo or mono jack) then weird stuff like that may happen.

LOL. yes I do know the difference.
my speakers has a stereo plug in front also, I can plug in head phones and hit mute on speakers.
The first time I used them I thought the speakers would not work with head phones plugged in. I was shocked that they still worked. I the hit mute and only head phones worked.

[Kevin Mullins]

LOL. yes I do know the difference.
my speakers has a stereo plug in front also, I can plug in head phones and hit mute on speakers.
The first time I used them I thought the speakers would not work with head phones plugged in. I was shocked that they still worked. I the hit mute and only head phones worked.

Ah..... yeah, that would throw me off a bit too.

[Zebidee]

I hope somebody makes some use of the confusion. 

Likewise!   

What I was trying to promote was a a linear or logical approach using discrete components in series. In other words, run the signal through vol pot and/or audio jack before it gets to the amplifier, rather than trying to modify the amp itself or splitting signals (or hairs).

The guide doesn't cover audio jacks because there are many different ways to do this, many of which do not involve actually directly wiring up the audio jack. In fact, my favourite way involves re-using the little front-panel PCBs that many PCs have, mounting that behind a control panel fascia and extending the cable by a metre or so (anything over two metres might start to cause problems).

Maybe I should do a page on making little admin control panels from top to bottom, complete with headphone jacks, volume controls and USB ports. Here is an example of one I installed into an existing hole for a coin mech:

[ArcadeBliss]

OK, I followed your plan and used a 100K pot. It is wired as such:

PC -> POT -> Headphone Jack -> PC Subwoofer (powered)

As it should, when I insert my headphones, it cuts out the line going to the PC Subwoofer, which of course was the desired effect. The problem I am having is that the headphone volume ist wayyyyy to low and does not adjust to changes of the pot (twisting the knob). Only when you adjust to pot to full (= 0 resistance) does the volume turn all the way up.

After talking with a few friends of my, the consences seems to be that a 100K pot is way too large for the widerstand found in your garden variety headphone (4 - 16ohm). They suggested I replace the pot with a 1K pot.

What would this do to the connection going to the pc speakers. I have no clue  Is this even a choice? How did you solve this problem? (Questions, questions, questions...)

I hope somebody makes some use of the confusion. 

Likewise!   

What I was trying to promote was a a linear or logical approach using discrete components in series. In other words, run the signal through vol pot and/or audio jack before it gets to the amplifier, rather than trying to modify the amp itself or splitting signals (or hairs).

The guide doesn't cover audio jacks because there are many different ways to do this, many of which do not involve actually directly wiring up the audio jack. In fact, my favourite way involves re-using the little front-panel PCBs that many PCs have, mounting that behind a control panel fascia and extending the cable by a metre or so (anything over two metres might start to cause problems).

Maybe I should do a page on making little admin control panels from top to bottom, complete with headphone jacks, volume controls and USB ports. Here is an example of one I installed into an existing hole for a coin mech:

[Zebidee]

Hmmm

Do you have both speakers wired through a double-ganged 100k pot? Also, I need to know if you have a linear or a logarithmic pot.

I have had your experience. I suspect that you are using a cheap log pot. What this means is that the log pot as two resistance tapers (zones of movement) rather than just one (more expensive log pots have just one element with resitance varying over it's length, and if you graph it you get a logarithmic curve, not a linear (straight) curve, that provides for a smoother transition).  This first taper gives slow adjustment, and the second taper (once engaged) allows for fast adjustment at the top-end (this behaviour matches your description). It is clunky and does not sound good at all - and is not what log pots should be.

Although theoretically designed for audio applications, the reality is that they are all made cheap-and-nasty these days and it is difficult to get anything else (manufacturers of quality audio products probably get their own made to spec). I have NOT had good experiences using these and generally prefer the linear pots instead.

More on pots and logarithmic tapers:
http://sound.westhost.com/pots.htm
http://en.wikipedia.org/wiki/Potentiometer
http://www.geofex.com/article_folders/potsecrets/potscret.htm

Taper    Old Code    New Code    
Linear     A                  B         
Log         C                  A         
Antilog    F                 N/A     

You can try other resistance values - anything from 10k to 100k is fine, and I have had probably best results with 50k linear pots.  However, 1k would be a bit too small I think. I would recommend that you try a linear 10k-100k pot before a 1k pot. A 10k linear pot is commonly used in button headphones designed for use with PCs (I have pulled sets apart and tested them).

Good luck! Photos?

[ArcadeBliss]

Thanks for your reply. What do you mean by both speakers? The left and right signal from the pc (speaker out) is wired to the pot. Just like your setup, I have one (line in) cable that is fee d into the subwoofer. From the subwoofer, the speakers are wired into that. The subwoofer runs fine and reacts to the pot movements.

I have a 100K Linear pot. The writing on the side says 100KB.

I guess pictures are worth a thousand words - here you go.

Let me explain what you will be seeing:

Front.jpg: This is the front of my panel 2 buttons Exit and Tab, 2 USB Ports, 2 Composite Sync Ports, the Volume Pot handle, and 2 headphone jacks.

Back.jpg: (see front.jpg)

input.jpg: the rightmost cable is from the pc and goes to the pot. Next to the pc cable is the subwoofer "line-in" cable. It is feed from the first headphone jack. (see wiring.jpg)

[Zebidee]

Looks like your headphone jacks cut the active signals, not ground?

You seem to have a linear pot, but perhaps a 50k or 10k pot would work best, especially if you are finding that all the volume variation happens over a small part of the knobs' rotation (I have seen a little of this with 100k pots too, but never enough to worry me at normal amplifier output levels). I still think that 1k is a bit too small though. I have had the best results using some small B50K dual-gang pots (linear) that I de-soldered from old PC multimedia speakers (I couldn't find exactly the same ones at Jaycar, which is a popular electronics parts shop in Australia).

[ArcadeBliss]

OK, I received feedback from the friend of mine too. He advised me to use a 10K pot. I'll give that a try this weekend.