Why won't anyone make a portable DAC bypass for iPod?
Apr 23, 2008 at 12:47 AM Thread Starter Post #1 of 17

Singapura

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Like many out here, I've noticed a trend towards portable DAC's with or without amp. At the same time there is still demand for the iMod, gMod and the like. It would stand to reason that instead of bypassing the crappy iPod caps with an expensive solution and special cables, it would be much better to bypass the DAC altogether using the iPod's digital out option. I know there's one product that can do that, the Wadia, but instead of making it portable they market it as a desktop solution. I don't get that!
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. Why sell an iPod dock when there are already many ways to make a music server? Why sell portable DAC's if the only way to use them is to carry your laptop around?

Is it just me or is someone missing a marketing opportunity here? I can't believe that the Apple "authentication chip" is so large that you can only use it in a standalone dock the size of an shoebox. If the iPod has the ability to provide a clean digital signal someone should be able to use that (even if it takes an Apple licence to do so). So, here's to all you Apple accessory farmers out there. Please make a portable digital out solution for the iPod.
 
Apr 23, 2008 at 3:47 AM Post #4 of 17
Good luck convincing Apple to add a USB host to the iPod. =p
 
Apr 23, 2008 at 4:58 AM Post #5 of 17
You'd need more than USB host, you would need drivers and a more complex OS.

I think the ideal solution would be digital coax or optical, but too bad hardly any amps have those inputs.


Also there's a huge thread about the ipod digital out in the DIY area, maybe you've seen it.
 
Apr 23, 2008 at 9:12 AM Post #6 of 17
Quote:

Originally Posted by nfusion770 /img/forum/go_quote.gif
With the advent of all the portable amp/dac combos, I'd love to see a USB or optical option for the ipod. Ipod to pico dac would take portable to the next level. I have no idea of the viability of such a product, however.


I actually know someone who rigged a Pico to use an iPod through USB. They used an iPod USB adapter for a Cadillac that contains the authentication chip. I think you have to own one of the cars and pay about $300 for one. But you then need a 5V power source for the USB DAC, since it won't take the power from the iPod. Only a big company, for high-end audio, could afford Apple's license fee
 
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Apr 23, 2008 at 2:27 PM Post #7 of 17
In theory, one can wire up an iPod to feed the Pico, but it'd be extremely annoying and impractical to pull it off. The iPod's Wolfson uses an I2S signal which is also what is used in the Pico. You can send that signal to the dock's unused pins. Then you need to send that signal to the Pico's DAC while, as Justin mentioned, powering it with 5V. All this is accomplished through the mere connecting of super tiny wires to a bunch of super tiny pins (4 for the iPod's DAC, 4 for the dock inside the iPod, 4 for the dock connector, 4 more for inside the Pico if you hardwire the dock into the Pico, and probably 8 more if you don't hardwire it). Then you have to supply the DAC with 5V, which would probably require some sort of additional battery pack. That's more than enough for a good number of our resident DIYers to handle.

Give this thread a good run through:
http://www.head-fi.org/forums/f6/diy...al-out-288449/
 
Apr 23, 2008 at 4:54 PM Post #8 of 17
The DAC built into the iPod is as good or better than most home CD players. What's the point of an external DAC for portable use? If portability doesn't matter, you might as well use a laptop computer with USB or optical out.

See ya
Steve
 
Apr 23, 2008 at 8:45 PM Post #10 of 17
Quote:

Originally Posted by bigshot /img/forum/go_quote.gif
The DAC built into the iPod is as good or better than most home CD players. What's the point of an external DAC for portable use? If portability doesn't matter, you might as well use a laptop computer with USB or optical out.

See ya
Steve



Computer to Pico sounds better to me than IMOD to Pico. My assumption is that the Pico DAC is superior to the ipod DAC. It doesn't sound like there's an easy or readily available solution, however.
 
May 17, 2010 at 10:24 AM Post #11 of 17
yeah, im thinking that if I got a ipod dock cable > miniusb (like something that would fit the ibasso mamba, or e7, or something like that) would you need an authenticity chip IN THE CABLE in order to bypass the DAC?  I wouldn't be able to just fool the ipod into thinking its connected to a computer and send the music to play through the DAC directly?
 
May 17, 2010 at 10:27 AM Post #12 of 17
Wadia are not the only company to make a digital solution for the ipod, Onkyo also do and it is considerably cheaper too.
 
May 17, 2010 at 10:40 AM Post #13 of 17
yes and so do pioneer car stereos, another new player in the portable audio market, whos name escapes me right now along with a couple of others. but as justin said its big money f you wanna do it legally. its the record companies that have held this uo for  so long, ot the technology.
 
John, you make it sound simple mate :wink: problem is i2s is a pretty fragile transport mechanism, that is primarily designed for getting data from point A to point B over very short distances, there is no standard for i2s interconnects although ethernet is one of the defacto standards.all those solder joints are gonna mess with the impedance and jitter in a bad way, best solution would be to use async with it on the dac end making the low quality i2s integrity a non-issue, then you would also only need a 2 or 3 wire connection
 
the i2s output from the ipod is going to be pretty low voltage as they go due to the 3.7v battery, i2s is a 5v standard in general, so it would need to be buffered  and then probably isolated from the ground noise etc. all possible, but as a diyer not really that attractive a proposition when there are easier routes to get i2s.
 
but the ipad has digital out with the camera connection kit, only for devices that are supported by the usb audio codec, there is also rumour the new iphone 4G will allow the same trick, if it does, count me in. all of these do require a power source to be useful , or the host's battery is drained quicksmart
 
May 17, 2010 at 10:52 AM Post #14 of 17
 
Quote:
but the ipad has digital out with the camera connection kit, only for devices that are supported by the usb audio codec, there is also rumour the new iphone 4G will allow the same trick, if it does, count me in. all of these do require a power source to be useful , or the host's battery is drained quicksmart

 
If the future iPhone will have this feature, could it be possible that the future ipod touch will have this nice funktion too?
 
May 17, 2010 at 5:36 PM Post #15 of 17
2 year resurrection
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Look at the thread in the portable amp section about the thing Fostex is working on
 

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