[ajames]

I just borrowed Apple's Universal Dock from a friend, and was surprised to find that when connected, the volume control on the ipod is not disabled.

Am i correct in assuming this is a tell-tale sign of the "Line Out" on the back of the Universal Dock to not be a true line out?

I've searched, and found a few conflicting pieces of info, and wanted to know if anyone knows what exactly Apple's done with their "line out" ...

Thanks!

 

[tpc41]

i think the dock itself has an attenuator built in

 

[shigzeo]

yes I wonder too that it might be an attenuator or else every other dock manufacturer are using fake line outs as they come from the same source.

 

[Punnisher]

So you mean when it's connected, you can adjust the volume with the wheel, and it gets louder/quieter when you do so?

Because the volume can be adjusted when using a line out, but it does nothing to the signal, it's a constant line level no matter what the volume is set to.

If this is true though, I'll just have to DIY my own dock, just to make sure.

 

[shigzeo]

I have several other sources with line outs whose output is controlled externally through software it does not mean they are not true line outs. It makes sense that apple can make a CPU component that has better integration than third party components. The signal is coming from the dock connector of the iPod meaning that if anything strange the sound comes
from the line out and then fed through a processor to the actual signal output. The connector also makes use of more than the two wires only that other lods use

 

[tpc41]

i think they only do this so that the volume can be adjusted with a remote, it is definitely not the same signal that comes out the headphone jack, its a night and day difference in sound quality

 

[shigzeo]

I am not sure I would say night and day different as still it is coming from the same hardware. Besides, the iPod hp already sounds pretty good

 

[ajames]

I suspect that as well. In talking with a friend and apple fanboy, he pointed out that the same thing is not true for his iPhone dock's line out ... which of course has no IR remote capabilities.

And yes, the scroll wheel also controls the volume, despite the line out being run straight to my amp from the dock.

The question is now: Will a simple line out to 3.5mm jack sound better than the universal dock's signal --> built-in attenuator --> mini-to-mini?

 

[tpc41]

the difference between the ipod line out through the dock and the ipods headphone out is a huge difference when connected to an amp

 

[That dude]

I myself believes that sometimes in audio, less is more. For example if you use a 1/8'' to 1/4'' adapter, it resistance is added on which changes the sound a little. An attenuator then, if not needed, is best not added. A classic example is the removal of the volume control pod of the im716. Many claim that the sound quality improves dramatically. [Personally I haven't heard it].

*edit: If you can get hold of the ipod "line out docks", which disables the volume controls, it would be best.

Btw, the Ipod's lineout is never "true" since the sound still reacts to EQ settings. About the volume control, I'm as confused as you are.

 

[ajames]

I wonder if buying a knock-off brand ipod dock would loose the attenuator feature, and give me more of what i feel a "true" line out should be ... despite the apparent response to EQ, which i'm guessing affects any signal taken from the dock connector?

 

[JadeEast]

Here is a shot of the guts with a closeup of the codec.

 

[ajames]

Forgive my ignorance, but what exactly can be concluded from the above info?

Also, if there is additional attenuation build into the current docks, what about the previous generation docks without the remote control? Could a better line out be achieved using an older universal dock? And are 5th gen and up ipods even compatable with older docks, for that matter?

This is interesting, as i've found several older-gen docks on ebay that may do the trick on the cheap.

 

[JadeEast]

Don't have to ask for forgiveness it's not like I was very clear.

a yearago I was screwing around with the universal dock last year tying to figure out what was going on unside so I oppend it up. My best guess is that they use the codec in the dock to slave to the codec in the ipod to allow the remote control to work and they just resample the audio along the way. In the most basic sense the universal dock is not a "true line" as it does not simply pass the line level audio out.

 

[shigzeo]

its very much like a separate hifi connected to your hifi! personally i love it and find it very helpful and a perfect application to both charge and run my ipod at the same time - nothing that the alo, qables etc can do. i could care less for a bit of extra 'warmth' or whatever they claim you get with the docks.