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TRRS output from Apple Iphone 4
Lee Patzius:
First of all, greetings! And WOW! Another forum reset.
Well, anyway, I recently purchased my first piece of Apple gear, an Iphone 4, which IMO, is incredible piece of kit, to say the least.
But of course in all its greatness, I hit a snag.
That dog-gone TRRS headphone output!
My initial intent was to sign in and crank Pandora through our band's PA during setup, and breaks. So, with last minute intentions and no experimentation, and noticing Apple's OEM earbuds had 1/8" TRRS, I went out and found a 3 channel RCA to TRRS adapter and naturally ASSumed red and white RCAs were audio, (assuming yellow is reserved for things like video in its off the shelf intention) and further adapted the red and white RCA outputs to Male 1/4" TS each channel.
Of course, I ASSumed again, and made them semi-permanent with electrical tape over the various RCA to 1/4" adapters strung together so I wouldn't lose the matched pairs, without any pretesting... But NO!
For its first time trial, live on stage, at the last minute, trying to setup the PA for overall sound check, in frantic tunnel vision mode, with absolutely zero time available, signing into Pandora, which was paintstakingly slow, I finally get through only to find my adapter's red RCA channel coming from the adapter is a piece of crap.
Iphone 4 uses the White and Yellow RCA outputs for audio!
So, let it be known, for off the shelf 3 channel 1/8" TRRS to RCA adapters, the Iphone's output uses White and Yellow RCAs for audio output.
In addition, I placed a female to female RCA barrel over the exposed male Red RCA and taped it together as well, to keep its prong from going to ground.
Rory Maguire:
How curious... I don't use an iphone personally. Android user here!! But point well noted. Maybe I'll borrow a mates and do a little experimenting!
Have you tried multi metering your cable to check it's not just a stupidly mis-labeled RCA connection?
Larry Robbins:
I also bought a generic TRRS to 3 RCA adaptor and on mine, the yellow is the mic which I believe to be the ring closest to the sleeve. I think that it is the aftermarket cable maker's color coding that is what you found a surprise, not Apple's wiring scheme.
Ned Ward:
Lee - Apple does this so they can charge $30 for their proprietary AV cable, which as you've found just has the video and white for audio, red for video. Great for using an iPod that supports video with any camcorder RCA cable. I read about this back when I got my 60GB ipod and tried it out. Fun for the kids to play videos on long trips in the car.
FYI - a normal 1/8" TRS to stereo RCA works as expected for audio; I have 3 in my mixer drawer to use for iPod break music or for recording stereo in on my Zoom H2. There are also people that sell a line level out version that connects through the dock connector - http://www.moon-audio.com/Moon_Audio_Mini_Audio_Cables.htm - scroll down a bit.
TIP - go into settings and turn on Airplane Mode - this will silence any "didit didit didit didit" noise during performances.
Lee Patzius:
--- Quote from: Rory Maguire on January 08, 2011, 07:29:24 PM ---How curious... I don't use an iphone personally. Android user here!! But point well noted. Maybe I'll borrow a mates and do a little experimenting!
Have you tried multi metering your cable to check it's not just a stupidly mis-labeled RCA connection?
--- End quote ---
Well, curiousity got the best of me so I took some measurements.
I attached pics, but the preview button didn't confirm my upload.
In case my picture doesn't load, this is what I got:
TRRS Tip = RCA White
TRRS 1st Ring = RCA Yellow
TRRS 2nd Ring = RCA Ground
TRRS Sleeve = RCA Red
I'm surprised to say the least!
I did notice that if I plug a standard 1/8" TRS headset into my Iphone, they will play in stereo properly, even though they'd short out Apple's 2nd ring to sleeve.
One other thing to consider is the fact that my OEM earbuds have a cool push button volume control inline with the cable. That, along with other features I don't know about must be why they require an extra wire I guess.
But something tells me there may be something odd with the color coding on my Guitar Center's off-the-shelf TRRS to RCA adapter.
Without any searching, I'm kind'a wondering if this is normal, or did I get a bum unit?
Either way, it's no big deal. I'll just keep an eye out for it and leason learned...
NEVER ASSUME!
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