Hi - I'm trying to build an A/B/C switch to allow me to use a single headset (TRRS plug) and switch it between 3 different sources.
I am assuming this is a workable concept since A/B switches with TRS plugs are plentiful (Sescom SES-AB-SWITCH iPod/MP3 Player 3.5mm Stereo Audio A/B Switch), but I can’t find a 3.5mm TRRS A/B/C switch ANYWHERE.
I recently had a shop (kvconnection.com) try to build me one; they got it to work functionally but couldn't resolve a distortion problem with the headphone audio. They gave up on the project since they quoted a price that didn't allow for a lot of troubleshooting hours.
They felt the problem stemmed from the switch they chose - it was a rotary switch not intended for audio applications. The switch operation was 4 pole, 3 throw, on-on-on.
I have since found found this switch:
GuitarElectronics.com - 3-Way 4-Pole Guitar Toggle Switch-Chrome
I haven't bought it yet, but finding it gave me hope. I thought I'd consult some smarter people first to be sure I was on the right track.
Any advice/ direction regarding a suitable switch - as well as any insight into what steps I could take to insure distortion free operation - would be hugely apprecaited.
Thanks! JC
I am assuming this is a workable concept since A/B switches with TRS plugs are plentiful (Sescom SES-AB-SWITCH iPod/MP3 Player 3.5mm Stereo Audio A/B Switch), but I can’t find a 3.5mm TRRS A/B/C switch ANYWHERE.
I recently had a shop (kvconnection.com) try to build me one; they got it to work functionally but couldn't resolve a distortion problem with the headphone audio. They gave up on the project since they quoted a price that didn't allow for a lot of troubleshooting hours.
They felt the problem stemmed from the switch they chose - it was a rotary switch not intended for audio applications. The switch operation was 4 pole, 3 throw, on-on-on.
I have since found found this switch:
GuitarElectronics.com - 3-Way 4-Pole Guitar Toggle Switch-Chrome
I haven't bought it yet, but finding it gave me hope. I thought I'd consult some smarter people first to be sure I was on the right track.
Any advice/ direction regarding a suitable switch - as well as any insight into what steps I could take to insure distortion free operation - would be hugely apprecaited.
Thanks! JC
That's strange, a standard switch should work fine. Off the shelf 4 pole, 3 throw is what I'd get. But that switch you linked to is some kind of specialty thing, the positions won't allow you to do the switching you want. Any standard 4 pole 3 throw will have 16 connections, for each pole you should have a common (the destination in your case) and three switched connections (the sources). Something more like this: KC43A30.001NLS E-Switch | EG1958-ND | DigiKey, but I suspect that's the same basic thing that was used in the switch that didn't work for you.
I bet the problem stems more from a wiring issue (either wiring in the switch or between the things being connected). Can you give more detail about what the headset, and sources are?
I bet the problem stems more from a wiring issue (either wiring in the switch or between the things being connected). Can you give more detail about what the headset, and sources are?
Thanks a lot MuddJester! The headset is a combination of AudioTechnica noise-cancelling headphones and an Antlion ModMic, plugged into a Y connector with a TRRS plug. The sources are a Dell laptop with a TRRS jack, a Mitel VoIP phone with a TRRS jack and my android smartphone with a TRRS jack. I want my A/B/C switch so I can listen to sweet tunes on my phone, but rapidly switch to calls from the other two sources as they come in. The headset rig works fine when I plug it into those individual sources, so I'm hopeful the A/B/C box and the 6" TRRS M/M jumpers I have will put me in business. If you think a standard switch fits the bill, I'll move ahead with the build.
Sorry to take so long to reply, I didn't get a notification you replied.
If the headset you're using works fine with the sources individually then a 4 pole switch will do the job, if wired correctly. With 4 poles, it's equivalent to switching the plug. All you need is good electrical contacts in the switch, that is low contact resistance and protected from dirt and dust. For what you're doing I can't think of a new switch that wouldn't be good enough (doesn't mean they don't exist). Also be sure to get TRRS jack and plugs. There are lots of connectors out there and if they don't have the right configuration you'll have trouble. I'd be happy to review any parts you're considering.
For hookup, you want the common connections for the 4 poles to go to your headset, and you want the others to go to your sources, just be sure to be consistent about which connections go where. That is, you want all the T connections together on the same pole, all the 1st Rs, and so on. A cheap multimeter will be valuable for debug if you have any problems. With it, you can check that the switch connections are what you thing they are.
If the headset you're using works fine with the sources individually then a 4 pole switch will do the job, if wired correctly. With 4 poles, it's equivalent to switching the plug. All you need is good electrical contacts in the switch, that is low contact resistance and protected from dirt and dust. For what you're doing I can't think of a new switch that wouldn't be good enough (doesn't mean they don't exist). Also be sure to get TRRS jack and plugs. There are lots of connectors out there and if they don't have the right configuration you'll have trouble. I'd be happy to review any parts you're considering.
For hookup, you want the common connections for the 4 poles to go to your headset, and you want the others to go to your sources, just be sure to be consistent about which connections go where. That is, you want all the T connections together on the same pole, all the 1st Rs, and so on. A cheap multimeter will be valuable for debug if you have any problems. With it, you can check that the switch connections are what you thing they are.
Oh goodness, no worries - thanks so much for the help! I think I'm ready to get going with this. Here's my parts list:
x4 3.5mm 4-Conductor TRRS Chassis Mount Snap-in Jack-Black
x1 KC43A30.001NLS E-Switch | EG1958-ND | DigiKey
x1 3in X 2in X 1.1in Black Plastic Box Enclosure | MPJA.COM
x2 Mogami W2929 4c. 28awg Mini SH Cable .106in O.D. - per foot - Black
I think I'll be able to get this if I check it wire by wire. Let me know if you think any of the parts I spec'ed aren't right.
Thanks again - John
x4 3.5mm 4-Conductor TRRS Chassis Mount Snap-in Jack-Black
x1 KC43A30.001NLS E-Switch | EG1958-ND | DigiKey
x1 3in X 2in X 1.1in Black Plastic Box Enclosure | MPJA.COM
x2 Mogami W2929 4c. 28awg Mini SH Cable .106in O.D. - per foot - Black
I think I'll be able to get this if I check it wire by wire. Let me know if you think any of the parts I spec'ed aren't right.
Thanks again - John
Looks like shipping is going to end up more than the parts. A single supplier may be cheaper.
I don't see any problems here. Unfortunately, there isn't a spec sheet on the TRRS jack, but it should be what you need. Inexpensive switch, but again, should work. Keep in mind you may get popping when changing channels due to breaking connections and different levels on different channels. The cable is on the small size, I prefer not to go below 26 AWG. If you're comfortable with it that's fine. The cable has a shield, you won't have anywhere to connect that from what I can see (normally I would suggest case, but that's plastic here). Best not to leave shields un-terminated, could add noise. You probably don't need a shield with twisted wire, but if you do get the shielded cable connect the shield to the ground terminal of one end (or both, whichever gives better results).
You'll need TRRS plug to plug cables for your sources.
I don't see any problems here. Unfortunately, there isn't a spec sheet on the TRRS jack, but it should be what you need. Inexpensive switch, but again, should work. Keep in mind you may get popping when changing channels due to breaking connections and different levels on different channels. The cable is on the small size, I prefer not to go below 26 AWG. If you're comfortable with it that's fine. The cable has a shield, you won't have anywhere to connect that from what I can see (normally I would suggest case, but that's plastic here). Best not to leave shields un-terminated, could add noise. You probably don't need a shield with twisted wire, but if you do get the shielded cable connect the shield to the ground terminal of one end (or both, whichever gives better results).
You'll need TRRS plug to plug cables for your sources.
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