# 3.5mm jack, 3 pole should be enough, why bother 4 or 5 poles?



## diablo9

Ordering some 3.5mm jacks, see this PDF:
http://dkc3.digikey.com/PDF/T053/0287.pdf

 Why the same jack always have 3 versions, 3 poles, 4 poles and 5 poles. Such as fig 58, ABC versions. Wouldn't 3 poles be enough? What's the point of the 4 pole and 5 pole version? or they have some special purpose? 

 and anybody knows the difference of CP-3535N-ND and CP*1*-3535N-ND?


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## thecmoy

Think about the iPod (color screen) for example. You can buy a cable for it that has 4 poles, left, right, ground, AND video out, all for hooking it up to a tv. so i guess when you get to 4 or 5 poles, 3 are for audio and the remainging 1 or 2 aare for other purposes.


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## diablo9

Quote:


  Originally Posted by *thecmoy* 
_Think about the iPod (color screen) for example. You can buy a cable for it that has 4 poles, left, right, ground, AND video out, all for hooking it up to a tv. so i guess when you get to 4 or 5 poles, 3 are for audio and the remainging 1 or 2 aare for other purposes._

 

no, if you read the PDF, it shows that in 5 pole version, 2 poles are actually identical. They are connected inside the jack. And the 3.5mm jack only accept stand 3 pole male plug.


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## labrat

Deleted.


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## diablo9

Quote:


  Originally Posted by *labrat* 
_Why these jacks are made like this, I do not know. Made for special appliances maybe?
 But thecmoy is right, the colour iPod headphone-jack accepts a 3.5 mm plug with tip, two rings and sleewe and a 3.5 mm plug with tip, one ring and sleewe. The plug with two rings is slightly longer than the plug with one ring, and the tip on the longer one is connecting to composite-video-out signal from the iPod!
 Without the extra ring the plug is a standard headphone-plug._

 

thanks for info, but that still doesn't quite explain the 4 and 5 pole question since 2 poles are actually identical. looking for some other answers....


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## skyskraper

they're switched jacks. when you don't have any plug connected to the jack, then the extra poles are connected to the main poles. so say i want to have an rca input and mini input to an amp, then i can connect the RCA input to the extra poles of the mini jack. so that when there is no mini source plugged in the RCA input gets routed through the mini jack automatically to the input of the amp. and when the mini jack is plugged in then the rca is disconnected and the signal from the mini is fed to the amp


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## diablo9

Quote:


  Originally Posted by *skyskraper* 
_they're switched jacks. when you don't have any plug connected to the jack, then the extra poles are connected to the main poles. so say i want to have an rca input and mini input to an amp, then i can connect the RCA input to the extra poles of the mini jack. so that when there is no mini source plugged in the RCA input gets routed through the mini jack automatically to the input of the amp. and when the mini jack is plugged in then the rca is disconnected and the signal from the mini is fed to the amp_

 

so technically for the single input amp, the 3 pole version is always enough, right? 
	

	
	
		
		

		
		
	


	



 what about the difference of CP-3535N-ND and CP1-3535N-ND?


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## skyskraper

well the manuf doesn't show any data for the SJ-3535 just SJ1-3535 so it's possible that it's simply an updated version of the jack. 

 yep a 3 connector jack is fine. i find most of the jacks i come across are switched so i use them. on a preampi built i used the switching jacks wired to feed the left hand signal in to the right hand jack (effectively mono) if i don't have anything plugged in to the right hand jack.


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## diablo9

Quote:


  Originally Posted by *skyskraper* 
_well the manuf doesn't show any data for the SJ-3535 just SJ1-3535 so it's possible that it's simply an updated version of the jack. 

 yep a 3 connector jack is fine. i find most of the jacks i come across are switched so i use them. on a preampi built i used the switching jacks wired to feed the left hand signal in to the right hand jack (effectively mono) if i don't have anything plugged in to the right hand jack._

 

thanks, pal!


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## diredesire

Sorry to dig up a relatively "old" thread, but the 4 pin jacks are commonly used in A/V, not just "audio" For instance, they use a 4 conductor jack for video cameras/camcorders.


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## diablo9

Quote:


  Originally Posted by *diredesire* 
_Sorry to dig up a relatively "old" thread, but the 4 pin jacks are commonly used in A/V, not just "audio" For instance, they use a 4 conductor jack for video cameras/camcorders._

 

I think this 4 pin jack is different. As you can see in the PDF, in the 4 pin version, 2 of them are connected inside. I think the switched jack explanation makes sense.


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## DolbyR

is there actually a problem of not using switching jacks when using dual input? i've just ran the wires from the jack and the RCA's straight to the board. No switching jacks used. Is this a problem?


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## DaKi][er

Quote:


  Originally Posted by *DolbyR* 
_is there actually a problem of not using switching jacks when using dual input? i've just ran the wires from the jack and the RCA's straight to the board. No switching jacks used. Is this a problem?_

 

Only if you plug in 2 sources in at the same time


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## nikongod

Quote:


  Originally Posted by *diablo9* 
_thanks for info, but that still doesn't quite explain the 4 and 5 pole question since 2 poles are actually identical. looking for some other answers....



_

 

the ipod company (haha, fun stuff) may hve bought a batch of 5-pole jacks at a discount, or may use 5-pole jacks in a DIFERENT product (with all 5 poles) making the ease of buying 1 product outweigh the costs. also, the seperate poles may both be to ground, but they may be to grounds which canot be "influenced" by another signal.

 auto manufacturers OFTEN build wiring harnesses this way. LOTS of cars not equipt with abs/speed sensitive power steering/VTEC, etc have the wires already installed if that was an option in that model year& chasis. it costs less to make EVERY harness the same, and not use some stuff than to make 2 or 3 or more.


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## pressefr

diablo9 said:


> Quote:
> 
> 
> Originally Posted by *diredesire*
> ...


 
  
 I'm totally digging up an "old" thread, I found this as I was researching around wanting to know the difference from "3.5mm jack 3 pole should be enough, why bother with 4 to 5 pole," myself.
  
 I'm getting into Noise Canceling earphones, as the business-product-model is a bulky external pack or lion-battery. My first experience with this was a Sennheiser, AA battery packed collapsible headset, back in the day (prob when this post was up), it was pretty amazing tech as it wasn't widely used. Now, a decade later, Sony's mobile phone line has figured how to make the 3.5mm jack itself the power source taking out all the weight and using the phone for it's sensors more/less. This feature first started in devices like the Sony Xperia Z2s, Z3, Z3+, Z4, Z5, Z5 Premium, etc. for Noise Canceling in-hear bud products i.e.; Sony XBA-NC85d, Sony MDR-NC31em, and Sony MDR-NC750.
  
 Now my question is, are the 5 poles used for conducting power for "active noise cancellation" or for Hi-Resolution audio "Hi Res Audio"?


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## NiHaoMike

The interesting part is that just two years after the thread was started, TRRS headsets started becoming very common thanks to the iPhone and other smartphones.


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## Duncan

pressefr said:


> Now my question is, are the 5 poles used for conducting power for "active noise cancellation" or for Hi-Resolution audio "Hi Res Audio"?


Having bought the EX750, and having also just ordered the NC750 I can say that the NC750 has an extra fifth ring to cater for the stereo mics (so, assuming left / right input, left / right output and ground) - the EX750 only has four poles due to having the electronics for noise cancelling on the cable, so only needing the standard android / IOS connectivity (there is no remote functionality on the NC750 else that would get even more complicated!)

For what its worth, if it floats your boat having the NC750 allows you to record sound in stereo on the Z5 - weirdly handy if you're at a gig I guess


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## returntosennder

I actually came across a pair of Sony noise cancelling earphones with a 5 pole TRRRS 3.5mm plug back in 2009 (they were bundled with a Sony Vaio laptop).
  
 For active noise cancellation, there are small microphones placed inside the earpiece housing facing away from speaker. The signal from these microphones is then flipped 180 degrees by a digital circuit (which is the AA battery powered thingie) and fed back into the earphones/headphones. As a result the interference is completely destructive and the noise coming from outside is cancelled out.
  
 Conventionally, the circuit that performs the flipping and adding is either housed inside the headphones (Bose QC line), or is in a separate battery powered box in the cable. In those cases, a standard 3 pole TRS 3.5mm plug can be used, permitting the use of the earphones/headphones with most standard audio devices.
  
 In several Sony applications of the technology, the processing is performed at the source (inside the laptop/smartphone). So, two of the five poles of the TRRRS jack are for the microphones, while, the other two are for the standard audio signal. The flipping and adding is performed by the audio circuitry inside the device, either in the digital domain or in the analog domain (I'm not sure which). However, this means that the noise cancelling feature (and in many cases, the earphones themselves) can't be used with any other device.
  
 I hope that this answers your questions.
  
 Regards
 Sennder


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