Idea for Zune LO dock
Oct 15, 2007 at 7:22 PM Thread Starter Post #1 of 9

luckypictures

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So I was sitting on the toilet last night, where all great thinkers sit, and had an idea for a LOD for the Zune. It's not a perfect solution, but would at least provide a line out for those who have been dying for one. When I say it's not a perfect solution, it's really not, but it should, in theory, work.
All one needs to access the line out of the Zune is to have it be powered through the dock connector while accessing the line out pins. The pinout is readily available on different sites, including once or twice here. So, why not get a spare Zune housing, or any other small housing, and place a Zune battery inside. Follow with me here. By having the same battery as the Zune, it would be possible to power the Zune via the dock connector, and, thus, allow access to the sound pins. Now, inside that housing one could fit the battery, a USB charging port so that you can the spare battery, and any cap or resistor between the line out and the headphone out. Sure, a portable rig would now consist of three small devices, but for people dying for a LOD for the Zune, it would work. The only pins you would have to connect on the cable would be the power/ground and the sound. And with the clear window in the Zune housing, the guts of the dock would be exposed, and you'd be able to show off those expensive gaps and resistors.
Anyone?
Patent pending. Patent Pending. Patent Pending.
(See Simpsons episode #258 for reference.)
 
Oct 16, 2007 at 2:37 PM Post #2 of 9
Bump.
Anyone think it'll work? Want to try?
 
Oct 16, 2007 at 3:19 PM Post #3 of 9
I've read elsewhere that the line out from the dock is the same signal as sent to the headphones - ie. it is amplified just the same.

Also, are you sure that all the Zune detects is power on the dock connector? I believe the iPod uses specific resistor values across certain pins to detect different peripherals; the Zune may do something similar - or even worse, the output may be switched on via a digital interface.

Even so, I don't think it'd be worth it personally. You'd be carrying around two batteries but would only be using one, and the Zune already sounds decent to my ears. From what I've read, the DAC has an integrated headphone amplifier that can't be bypassed in the Zune hardware...

But just get a cheap 5VDC wallwart and test it out. If you get signal, go for it!
 
Oct 16, 2007 at 8:52 PM Post #4 of 9
Quote:

Originally Posted by error401 /img/forum/go_quote.gif
I've read elsewhere that the line out from the dock is the same signal as sent to the headphones - ie. it is amplified just the same.

Also, are you sure that all the Zune detects is power on the dock connector? I believe the iPod uses specific resistor values across certain pins to detect different peripherals; the Zune may do something similar - or even worse, the output may be switched on via a digital interface.

Even so, I don't think it'd be worth it personally. You'd be carrying around two batteries but would only be using one, and the Zune already sounds decent to my ears. From what I've read, the DAC has an integrated headphone amplifier that can't be bypassed in the Zune hardware...

But just get a cheap 5VDC wallwart and test it out. If you get signal, go for it!



Hahhaha. Well, I've read the pinouts, and there are certain pins that are activated for certain accessories, yet. I'm in way over my head, I need to study up a bit.

But for anyone else, HERE is the most comprehensive info on Zune pinouts.
 
Oct 17, 2007 at 9:22 AM Post #5 of 9
Well I have been trying for months now to build a Zune LOD but no luck sofar.
And I do have a zune and dock for investigations, but I have not yet been able to activate the Zune line out (pins 13 and 14) different then by placing it in the dock. I openend it all up stripped it down and simulated nearly every possible event....no luck.

Several people have tried as well to activate the line out but it is apparently a combination of things that we have not yet been able to figure out.
I know how the DAC chip activates its secondary line out (the line out is fed from a different DAC output then the headphones line out) but not how this is 'keyed' to putting the Zune in its dock.

If you would find it, I would build you an LOD for free!

Well lets keep trying anyway, someday we will succeed.

The line out is as far as I am aware not the same as the headphone out since the Zunes volume control has no influence, the dockstation however contains an amplifier and amplifies this signal.

Rgds Hans
 
Oct 17, 2007 at 1:14 PM Post #6 of 9
Quote:

Originally Posted by hoosterw /img/forum/go_quote.gif
Well I have been trying for months now to build a Zune LOD but no luck sofar.
And I do have a zune and dock for investigations, but I have not yet been able to activate the Zune line out (pins 13 and 14) different then by placing it in the dock. I openend it all up stripped it down and simulated nearly every possible event....no luck.

Several people have tried as well to activate the line out but it is apparently a combination of things that we have not yet been able to figure out.
I know how the DAC chip activates its secondary line out (the line out is fed from a different DAC output then the headphones line out) but not how this is 'keyed' to putting the Zune in its dock.

If you would find it, I would build you an LOD for free!

Well lets keep trying anyway, someday we will succeed.

The line out is as far as I am aware not the same as the headphone out since the Zunes volume control has no influence, the dockstation however contains an amplifier and amplifies this signal.

Rgds Hans



Electrically, what's in the dock? Is there a microcontroller, or just passives and the amp? I'm guessing that there's probably some command that needs to be sent to the Zune to enable the line out. You'd need a logic analyzer or digital scope to check it out in that case. If you can figure out what signal needs to be sent, it should be easy to make a 'mod chip' from a small PIC or AVR.
 
Oct 17, 2007 at 1:42 PM Post #7 of 9
Quote:

Originally Posted by error401 /img/forum/go_quote.gif
Electrically, what's in the dock? Is there a microcontroller, or just passives and the amp? I'm guessing that there's probably some command that needs to be sent to the Zune to enable the line out. You'd need a logic analyzer or digital scope to check it out in that case. If you can figure out what signal needs to be sent, it should be easy to make a 'mod chip' from a small PIC or AVR.


There is a micro chip inside, so it could be well the case.

I do not have that kind of equimpment though. sorry.

Thanks anyway.

Hans
 
Oct 17, 2007 at 2:35 PM Post #8 of 9
If anyone who owns a Zune dock has some extra cash and the inclination, a DIY-ish logic analyzer that looks to be quite powerful can be had by purchasing a Spartan 3 Starter Kit from Xilinx (149.99) and running this on it.

Unfortunately I don't have the board, or I'd be willing to analyze someone else's dock. This looks really cool for $150 though, so I may purchase one next time I make a DigiKey order....
 

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