iPod Touch 4G 30-pin Connector Schematic

[undertone]

Does anyone have the 30-pin connector schematic for the newest iPod Touch 4G? Typically this isn't only pinout information, but also electrical signal levels to control pins for enabling specific functions

This new iPod no longer has analog inputs, but is equipped with a USB input, and iOS 4 accepts class-compliant USB audio. So I'm dying to try a powered USB DAC in order to use a quality digital input for recording.

Feel free to PM me...

[qusp]

i think you are mistaken wrt usb audio being as siple as knowing the pin info, it is protected oem licensed information that will require dsp for both usb out and in. check pinouts.ru for the latest pin info, but you are getting ahead of yourself imo

[undertone]

You could be right, but the fact that the Camera Connector Kit (CCK) on the iPad allows for a number of "un-supported" class-compliant USB audio devices (like the Apogee MiniMe) to work as audio I/O suggests that the same is possible on the iPod Touch 4G (iPT-4G). Here are a few interesting references on the subject:

Gearslutz CCK for iPad discussion

Audiophile Engineering iPT-4G audio I/O discussion

iConnect USB MIDI interface for iOS (and iPT-4G)

So technically it would seem that the iPT-4G has a USB input, like the iPad. Unfortunately this can't be confirmed because NO INFORMATION on the iPT-4G's 30-pin connector is publicly available. And apparently the CCK doesn't work on the iPT.

[qusp]

yes i'm aware of all that, i own an ipad, camera connection kit and several dacs that work with it, basically as long as the usb audio capable 1.1 receiver and dac runs under its own power, or draws exceedingly low power it will work, i used the cck in combination with an adum usb isolator and battery pack to provide a powered usb output on my ipad to allow use with more and it works great.

on the outside it would seem possible to use with the touch as it uses the same, or very similar chipset and software, but take it from someone who has tried the camera kit with the touch 4g and an entire thread on headfi who would have loved this to work to use touch with portable dacs and headphone amps, it doesnt there is a software/dsp interface issue.

good luck, but i have grave doubts

[undertone]

Thanks for the update. I skimmed through the Headfi thread, but all that confirms is that the CCK doesn't work with the iPT.

Originally Posted by qusp

there is a software/dsp interface issue.

Until we know for sure how the 30-pin connector is configured, and what switches are required in the connector to enable specific functionality (look at the older specs on pinouts.ru), and that Apple has decided to kill the digital input on the iPT-4G, we can't be sure of that.

It's a very big mystery: on the one hand the new hardware design of the iPT-4G has made it impossible to input a stereo line input, making a slew of analog mics instantly obsolete because it now only has USB input for audio, and on the other hand there are no stereo-in replacements and there's only one ADC coming out in short order (the Apogee Jam) advertised to work only on the iPhone and iPad, but according to the product page, not the Touch, which is odd because all the promo material on other sites refer to it working on the Touch.

So maybe you're right and Apple has clipped any chance of a stereo digital input for the iPT-4G, but some suggest it's just a matter of time. I would just like to know for sure; I have a feeling we'll know soon enough.

[qusp]

how the the connector is configured i feel is meaningless, its use will be under licensing agreement, because anything that allows input opens doors for digital output (record companies do not like this) as well and the key to these functions is held by a select few companies that have paid licensing and anyone that publishes such info will be opening the door to a law suit.

the key appears to be in software and dsp, nothing to do with the 30 pin connector, the usb pins are well known, but unocking their use for such functionality requires information under lock and key. the cables used for digital input and output are just standard dock to usb connectors using the same pins that are well known for data +/-, 5v and ground, no secrets there.

i do not think it will become clear anytime soon, but like i said, good luck