How to split one audio output conserving insert switch system ?

[Aramir]

Hello

I'm building my own arcade bartop and struggling with the audio system. I'll be honest I'm using cheap speakers ( Haut-parleurs stereo Logitech Z150 pour ordinateurs, tablettes, telephones ) hooked on some cheap TV I had lying around for that.

But it's not enough because what I'm trying to do is hijack the output jack's speakers and turn it into a dual output jack output (using those female connectors "Radioshack 3,5mm Headphone jack" [Guide] Audio-/Headphone Jack Information Thread - sudomod), so that I have speakers inside the cab and two jack in the front panel. Easy enough, but I'd also like to keep the "insert switch" system so that when there is no headphones, the sound comes from the speakers, but as soon as there is ONE heaphones connected to the hijacked front jacks the speakers cut off. (Also I'm gonna add potentiometers to adjust each jack volume)

tldr : can I split one jack output into two and keep the "insert switch" system effective on both jacks ?

Thanks for reading and even more thanks to those answering.

PS : @mods, sorry if posted in the wrong section, I'm really new to this audio world so I'm not even sure where I should have posted ...

 

[scottjoplin]

You could do it by connecting one speaker wire to one jack switched contact and one to the other contact on the other socket. That way when either jack has a plug inserted the speaker circuit is broken.

 

[Aramir]

You could do it by connecting one speaker wire to one jack switched contact and one to the other contact on the other socket. That way when either jack has a plug inserted the speaker circuit is broken.

wouldn't it be risky for the pcb/amp ? cause I'd throw the speakers signals in the jack part of the pcb. Should I add a heating element in between to avoid frying whatever headphone I plugin ? Maybe I should take pics to better explain the situation.

(Sorry for the late answer, I couldn't access the site for some reasons , some DNS shenanigans)

 

[scottjoplin]

I presumed that at the moment the speaker was disconnected when the headphones were plugged in due to the contacts opening on the socket.
Yes, do whatever you can to make the explanation clearer, I struggled to understand what you were asking

 

[Aramir]

Well actually the headphone circuit is always closed (take a look at [Guide] Audio-/Headphone Jack Information Thread - sudomod for more informations on jack socket). And I presume that at the moment you insert headphones, the pcb detects a change in independance (due to the headphone's resistance) and because of that it kills the jack part of the board and decides to turn on the speaker part.

Pictures and poorly draw electronic schematics will come tomorrow as it's near midnight around here and I got to wake up extra early. But thanks a lot for answering nonetheless, I took good note of your idea.

 

[PRR]

There's jacks to break the speaker line when you plug headphones in.

If you "tease" the plug, yes, you can find a position where both speakers and phones play. This is often no real problem, since it is momentary.

Having two phone jacks so EITHER jack kills the speakers is more complicated with simple switching jacks. Yes, with fancier circuit you can detect jack load and do something to switch the outputs. Either two amps each with standby pins, or a relay.

However we'd typically have one switched and one un-switched jack, and always put the first headphone in #1 jack (to break speakers).

There are related problems in guitar amplifier speaker jacks. One jack switching-out the internal speaker and powering an external is simple. Multiple jacks are not easy. Especially at stage-amp power levels and musician's budgets. Complex rules of jack-order will not be followed late at night on a dark stage with a few beers while chatting-up some foxy fans.

 

[Aramir]

@scottjoplin

Ok so here's a picture to better illustrate what I'm trying to achieve:

(I forgot to add that speakers the PCB will be pluged in the tv. Video and Audio coming from a raspberry pi throught hdmi)

And here's the speaker PCB I'm tinkering with, including previous illustrations of jack and stuff (Save it or click it as diyaudio forum seems to stretch the picture):

Hopefully it helps making sense of the situation.

@PRR
yes, having only one of the jack breaking the speaker circuit is pretty easy to do. And yes I was coming to you guys looking for a multiple jacks solution because I'm a perfectionist I guess ^^"

 

[scottjoplin]

I presume that at the moment you insert headphones, the pcb detects a change in independance (due to the headphone's resistance) and because of that it kills the jack part of the board and decides to turn on the speaker part.

If that's the case I'd suggest wiring the two sockets in parallel and see if it still functions in the same way. If not, keep it simple, and switch out the speakers

 

[Aramir]

If that's the case I'd suggest wiring the two sockets in parallel and see if it still functions in the same way. If not, keep it simple, and switch out the speakers

Already tried it and it doesn't work. I assume it's because it acts like this :

 

[scottjoplin]

Without anything plugged into the second jack the impedance would not change. Check your wiring to the sockets, make sure you haven't used the switched contacts

 

[Aramir]

Without anything plugged into the second jack the impedance would not change. Check your wiring to the sockets, make sure you haven't used the switched contacts

Yeah exactly it wouldn't change thus no change detected by the PCB therefore no turning off the speakers. I'm sure about my wiring on this one. :/

 

[scottjoplin]

What I mean is that it will be the same as with one headphone plugged into the first socket, nothing connected in parallel, no change. To confirm correct operation disconnect the second socket

 

[Aramir]

What I mean is that it will be the same as with one headphone plugged into the first socket, nothing connected in parallel, no change. To confirm correct operation disconnect the second socket

Now I'm the one at loss ... And I thought my english was correct . Still it looks like we both agree that mounting jacks in parallel is not enough. And like I said, I tried to wired it, it doesn't work. And obviously it did work with one. I might be the one starting to request poorly draw scheme or pictures ^^"

 

[scottjoplin]

Have you tried disconnecting the second socket to see if it works properly?