[eleventeen]

So...noob question but I knew that the sound gods here could answer this question:

When using a shielded cable (Like a Mogami or a Canare starquad) are you soldering the shield at both ends, ie. Dock Connector and 3.5mm plug, or leaving one floating?

The reason I ask is because common procedure is to leave the shield floating at the amp end, but I didn't know if it makes much difference for the length of this cable and it's application.

 

[HiFi1972]

 
Quote:

So...noob question but I knew that the sound gods here could answer this question:

When using a shielded cable (Like a Mogami or a Canare starquad) are you soldering the shield at both ends, ie. Dock Connector and 3.5mm plug, or leaving one floating?

The reason I ask is because common procedure is to leave the shield floating at the amp end, but I didn't know if it makes much difference for the length of this cable and it's application.

 
You terminate the shield at one end when making unbalanced connections, but in balanced TRS connections, the shield also carries audio information (on the gnd wire) so you definitely want that soldered at either end as well.
 
 

 

[kojl]

Does the line-in (pins 5,6) work this way?

 

[Tywin]

I have an old FM transmitter for my iPod that I have used for, oh, the last six years or so. The connector needs replacement, and I have finally gotten the replacement part in from SparkFun. The transmitter is sufficiently old that it does not work for iPads and iPhones, so in the process I will be attempting an upgrade with the 68k resistor on P21.
 
Will post back with photos when finished.
 
-T

 

[liamstrain]

I would be curious if this same configuration would work for the iPods as well (e.g. if you make for the iPhone it works for both, but not if you make just for iPod)

 

[mosesaro]

I was wondering the same thing a kojl. If these pins work and we short them with the ground we could make the smae remote as on the headphones. Also does this cable allow you to take phone calls
 

 

[Pingupenguins]

I ordered some 1/8 watt 68k's will they work? I've seen a lot of people running around with large resistors and I'm not sure if I have enough wattage on mine.
 
http://www.mouser.com/ProductDetail/Xicon/270-68K-RC/?qs=sGAEpiMZZMtlubZbdhIBIL1QqMQ78gJLqYwjzkwrgRY%3d

 

[fakcior]

Don't worry. It's enough.

 

[Pingupenguins]

Awesome. Is 3.5mm large compared to the pins on a LOD? I was hopping I could make it fit between pins 11 and 21 rather than making it bend back around.

 

[jeimen]

Sorry to resurrect an old thread but this is the best source of iPod LOD information that I could find so I thought that I'd come here looking for help.  The solution that is posted in this thread (pin 11 to pin 15, pin 21 to pin 15 via 68K resistor) works great for my old iPod Touch 2G but it doesn't behave well with my iPod Touch 4G.  With the 4G sometimes it will work fine.  Other times it will initially feed audio to the line out pins but after 20 seconds it will switch to the onboard speakers.  After another 20 seconds it may switch back to line out or it may continue to feed the onboard speakers.  The switching back and forth is a bit unpredictable but the 20 second interval is consistent.  Strange.  
 
I've got the following connections:
pin 11 connected to pin 15.  This should send audio through line out rather than the onboard speakers
pin 21 connected to pin 15 via 68K.  This should eliminate the pop up error on the iPod about accessory compatibility.
pin 15 connected to pin 16.  This is actually redundant since these are already connected in the iPod.
pin 2 to common line out audio on car stereo.  This is a line out signal to the stereo.
pin 3 to right line out audio on car stereo.  This is a line out signal to the stereo.
pin 4 to left line out audio on car stereo.  This is a line out signal to the stereo.
pin 16 to USB GND (from a USB adapter).  This is the ground for the 5VDC power supply.
pin 23 to USB 5 VDC (from a USB adapter).  This is the positive 5VDC supply.
pin 25 to USB Data - (from a USB adapter).  The voltage on the USB Data connections allows the iPod to accept USB charging.
pin 27 to USB Data + (from a USB adapter).  The voltage on the USB Data connections allows the iPod to accept USB charging.
 
On another website I saw that connecting pin 11 to pin 1 and 2, and pin 21 to GND via 500k works for some iPod Touch versions.  Does it matter which GND you connect 11 or 21 to?  Do 11 and 21 both need to be connected for the newer iPods?  Would the connections of the USB data signals conflict with the audio connections?
 
I can find plenty of examples of the iPod Touch 2G pinout but I can't find a pinout for an iPod Touch 4G.  Can someone give me guidance on the correct connections for reliable line out audio from a newer iPod Touch?  Thanks! 

 

[FraGGleR]

Quote:

Sorry to resurrect an old thread but this is the best source of iPod LOD information that I could find so I thought that I'd come here looking for help.  The solution that is posted in this thread (pin 11 to pin 15, pin 21 to pin 15 via 68K resistor) works great for my old iPod Touch 2G but it doesn't behave well with my iPod Touch 4G.  With the 4G sometimes it will work fine.  Other times it will initially feed audio to the line out pins but after 20 seconds it will switch to the onboard speakers.  After another 20 seconds it may switch back to line out or it may continue to feed the onboard speakers.  The switching back and forth is a bit unpredictable but the 20 second interval is consistent.  Strange.  
 
I've got the following connections:
pin 11 connected to pin 15.  This should send audio through line out rather than the onboard speakers
pin 21 connected to pin 15 via 68K.  This should eliminate the pop up error on the iPod about accessory compatibility.
pin 15 connected to pin 16.  This is actually redundant since these are already connected in the iPod.
pin 2 to common line out audio on car stereo.  This is a line out signal to the stereo.
pin 3 to right line out audio on car stereo.  This is a line out signal to the stereo.
pin 4 to left line out audio on car stereo.  This is a line out signal to the stereo.
pin 16 to USB GND (from a USB adapter).  This is the ground for the 5VDC power supply.
pin 23 to USB 5 VDC (from a USB adapter).  This is the positive 5VDC supply.
pin 25 to USB Data - (from a USB adapter).  The voltage on the USB Data connections allows the iPod to accept USB charging.
pin 27 to USB Data + (from a USB adapter).  The voltage on the USB Data connections allows the iPod to accept USB charging.
 
On another website I saw that connecting pin 11 to pin 1 and 2, and pin 21 to GND via 500k works for some iPod Touch versions.  Does it matter which GND you connect 11 or 21 to?  Do 11 and 21 both need to be connected for the newer iPods?  Would the connections of the USB data signals conflict with the audio connections?
 
I can find plenty of examples of the iPod Touch 2G pinout but I can't find a pinout for an iPod Touch 4G.  Can someone give me guidance on the correct connections for reliable line out audio from a newer iPod Touch?  Thanks! 

 
Have you tried simply using 2,3,4 for the audio with 11 and 15 bridged?  I have done that for an iPad 2 and it has worked flawlessly.  I can't find the source, but I thought I read that the pop up was done away with in the latest iterations of the OS.

 

[jeimen]

Thanks for the recommendation.  I will give it a try. 
 
I know that without the 68K resistor from pin 21 to ground I had the pop-up error with iOS5.  I haven't tried it with iOS6 though.  It would be nice if they eliminated the pop-ups.  They were a nuisance rather than a benefit.

 

[Mahay]

Does anyone know if it possible to replace the 68k resistor with a 100k 1/8watt?? Will it work with the all the generation of ipod/ipad (including the newest)?
Thanks

 

[qusp]

no, generally 67-69K will work theere is no way to cater for ALL, only most, there are a few models that broke from the norm. look at www.pinouts.ru for the ipod/iphone pinout info on all the models

 

[jeimen]

I fixed the problem with connecting my iPod Touch Gen 4 to my car stereo via line out.  Rather than make another custom cable I used a cable from Rocketfish:
http://www.rocketfishproducts.com/products/mobile-audio-video/RF-IPCAU6W.html
It has a 30 pin iPod connector on one end.  It has a USB connector and RCA plugs for audio left, audio right, and video on the other end.  Before the installation I checked the pinout of the Rocketfish cable to see how it compared to the pinout that was referenced earlier in this thread.  All of the GND connections are bonded together inside of the cable. Pin 21 was tied to Ground through a 500K ohm resistor.
 
Pin 1 GND
Pin 2 GND (connects to line out common in RCA plugs)
Pin 3 Line Out R (connects to line out right in RCA plugs)
Pin 4 Line Out L (connects to line out left in RCA plugs)
Pin 11 GND (this being tied to Ground sends audio through line out rather than speakers)
Pin 16 GND (connects to ground lead of USB adapter)
Pin 21 500K ohm connection to GND (enables serial communication)
Pin 23 USB Power (connects to 5VDC lead of USB adapter)
Pin 25 USB Data - (connects to Data - lead of USB adapter)
Pin 27 USB Data + (connects to Data + lead of USB adapter)
 
The 500K ohm resistor on pin 21 was needed to communicate with my iPod Touch Gen 4 and my iPhone 4S.  The 68K ohm resistor on pin 21 worked for my iPod Touch Gen 2 and my iPhone 3GS.  Hopefully this will help others who encounter this type of communication problem.