[Jade East]

Hope this is of interest to someone one out there.

I bought my wife a video ipod because she wanted something to play
music on and since I listen mostly to records and she has none, it
would let us have more music and less TV in the living room.
Part of the deal was that it has to be easy to use and look good so I
picked up the apple universal dock that would charge and link the
ipod to the preamp with the bonus of being able to use a remote.

Listening to the Ipod was Ok and I didn't have high hopes for it
, the bass seemed a bit rolled off through the line out and a bit
annoying. I had thought about getting the Imod but the ipod
had to keep its headphone out and it was my wife's desire to
watch some movies on the plane so the dock was a compromise.

Looking around the net I came across posts mentioning that
people had noticed that there was a sound improvement when
using the apple radio-remote and that it had a wolfson codec
inside of it as did the universal dock. My little tweak senses
were tingling.

So I cracked the Universal dock open and found a very small
circuit board inside with a wolfson WM8758ag codec chip
feeding the line-out. Unfortunately with no data sheet available
I was unable to get the exact pin out but with a bit of probing
found the output pins from the codec and corresponding surface
mount caps that I removed and soldered a 1uf Solen cap that
I had in my parts box to the pad where the old cap was.

Sound was clearer as the cliche goes a veil was lifted.

I am unsure if the codec inside the is acting as a slave to
the one inside the ipod or if it is being used by taking the
analog signal and passing it through. I have a feeling that
it is just taking the analog signal and passing it through.

The caps are too big to fit in the little box so I wired the
output mini jack directly to two small holes in the
circuit board as I had ruined one of the pads in my late night
rush. I had to put the caps inline on some interconnects that I
had made. If you were to use some blackgates or similar caps
they would fit inside the universal dock if you leave out the
metal weight that they have in there to stabilize the dock
and make it feel more solid. It is really small in there and
you have the potential to ruin the dock but it is much safer
than going into the ipod itself.

I may replace the Solens with an Auricaps of a larger value
or try a blackgate inside the unit. I feel like this has
made a positive difference in the sound of the universal dock
and there may be more potential to improve the audio quality
from this dock.

[boead]

Looking around the net I came across posts mentioning that
people had noticed that there was a sound improvement when
using the apple radio-remote and that it had a wolfson codec
inside of it as did the universal dock. My little tweak senses
were tingling.

??? Ummm, that insinuates that the apple radio remote and the universal dock have DA converters in them and that is the furthest thing from the truth.
Wolfson make DA converters, like Burr Brown. The higher-end Wolfson DAC’s are very good. The most recent iPods have DAC’s made by Wolfson but that doesn’t mean all that much.

The apple radio remote broadcast on an FM band.

Don’t expect much from an iPod no mater what you do.

[Jade East]

Wolfson wm8758ag is inside the universal dock, no insinuation just the truth.

[boead]

Ok, so do you know what the Wolfson wm8758ag is?

I serious doubt it’s a DAC, why would it be?

I searched Google and Wolfsons website and that part numbers doesn’t show up anywhere.

Anyway, have fun.

[Occam]

Just search on 'wm8758' and drop the silver.....

http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLR,GGLR:2006-06,GGLR:en&q=wm8758

[Vinnie R.]

Ok, so do you know what the Wolfson wm8758ag is?

Hi boead,

The WM8758ag is a Wolfson CODEC, and it does includes a DAC section.... digital goes in, analog comes out... I can promise you that!

You won't be able to find a datasheet on it because it is proprietary to Apple.

Don’t expect much from an iPod no mater what you do.

I disagree... using Apple Lossless or WAV (not compressed MP3 files) and one of the iPods with the Wolfson dacs, you'll get performance right up there with a high quality dedicated CD players. 

The 4th and 5th gen iPods are quite good (line out).  The digital and analog signal paths are very clean and very short, the data is taken off of a hard drive, buffered, and sent to what I believe are really good sounding Wolfson DACs. 

If the iPod was not highly mass-produced (hundreds of thousands), I am confident that they would cost at the very least 10x more that what they sell for (especially if it came from a small, audiophile company) and there would be a completely different attitude towards them in the high-end community.

Just my opinion, FWIW.

Best regards,

Vinnie

[boead]

Are you saying that the iPod sends a digital output to another DAC (high quality Wolfson) in a dock? That basically contradicts what is commonly known about the iPod and don’t you think that would make the dock an expensive and valuable device AND something that Apple would Market? Yet they don’t?

I’ll respect your opinion and judgment, mine is somewhat limited to a 3rd and 4th generation iPod but I’ve compared my 3rd gen and a friends 4th gen extensively and found it not all that good and that the difference between MP3 and WAV was almost indistinguishable. Similar opinions were shared from a few different Audiophile fussy-ass bastards I know. Oh and that’s using a wide variety of headphone amps, some costing over $2000 with a wide variety of headphones. I’m not basing my opinion with a cheap ear bud and no amp.
Actually I found that an old Nomad Jukebox sounded better then the iPod but next to that the iPod and Creative Zen were/are by far the best sounding DAP’s available. However, my iRiver portable CD player still sounds WAY better then my 3G or 4G iPod, it also has more drive.

Maybe I’m just going deaf.

I do believe that the iPod sounds better then the overwhelming majority of computers out there. So yeah, the ipod and creative zen sound excellent in comparison to that. When comparing my ipod to any of the dozen or so M-Audio cards I’ve owned, the M-Audio sounds significantly better and easily displays an audible difference between MP3 (320kbps) and WAV. I guess its all relative. My current Scott Nixon USB DAC sounds better then most CD Players and DAC’s I’ve owned.

[Vinnie R.]

Are you saying that the iPod sends a digital output to another DAC (high quality Wolfson) in a dock? That basically contradicts what is commonly known about the iPod and don’t you think that would make the dock an expensive and valuable device AND something that Apple would Market? Yet they don’t?

Hi boead,

I'm not sure about that dock that Jade East posted about... I am only familiar with the older docks that didn't have the Wolfson CODEC.  Based on the pic that he posted, I know it is dac, but I am also not sure why it is built into the dock  .   Any insight on this, Jade East?

Yes, the iPods do not offer an spdif digital output.  Apple should offer this, dammit!
These guys mod 'em for spdif output:
http://www.msbtech.com/products/iLink.php

I wouldn't mind one! 

I’ll respect your opinion and judgment, mine is somewhat limited to a 3rd and 4th generation iPod but I’ve compared my 3rd gen and a friends 4th gen extensively and found it not all that good and that the difference between MP3 and WAV was almost indistinguishable.

Not to be a shill for the iMod,  aa but the difference between MP3 and WAV in the modded iPod is VERY noticeable.  I can't stand anything lower than the 320k MP3s. 
I use Apple Lossless with the iMod and it sounds the same as WAV to my ears.

At the next shows that I'll be exhibiting at (Montreal and NYC), I'll have the iMod there just like I have at the past shows... that Wolfson WM8975 dac sounds really sweet!  While I admit that it is not the last word in obtaining that last ounce of detail, it is very well-balanced and musical sounding.  Some may prefer more detail, but I find it has plenty...

Maybe I’m just going deaf.

I doubt it... everyone has their own tastes.  Could also be a synergy (or lack of synergy) thing... I dunno.  I also respect your opinion/judgement.

Best regards,

Vinnie

[boead]

I'm not sure about that dock that Jade East posted about... I am only familiar with the older docks that didn't have the Wolfson CODEC.  Based on the pic that he posted, I know it is dac, but I am also not sure why it is built into the dock  .   Any insight on this, Jade East?

Yes, the iPods do not offer an spdif digital output.  Apple should offer this, dammit!
These guys mod 'em for spdif output:
http://www.msbtech.com/products/iLink.php

Oh, ok now I understand better. This dock isn’t the one that the older iPod came with and is an option for the newer generation. Then who makes it? Jade East? And that would still mean that the iPod is sending SO type of digital signal out to it – OR – its being used for something else but what?

Yes, spdif from a DAP would be GREAT!!

 

Not to be a shill for the iMod,  aa but the difference between MP3 and WAV in the modded iPod is VERY noticeable.  I can't stand anything lower than the 320k MP3s. 
I use Apple Lossless with the iMod and it sounds the same as WAV to my ears.

At the next shows that I'll be exhibiting at (Montreal and NYC), I'll have the iMod there just like I have at the past shows... that Wolfson WM8975 dac sounds really sweet!  While I admit that it is not the last word in obtaining that last ounce of detail, it is very well-balanced and musical sounding.  Some may prefer more detail, but I find it has plenty...

I believe you. I bet there is much room for improvement in an iPod. I’m NOT one of those that like lots of detail, I find that too much can be non-musical. The Scott Nixon NOS DAC isn’t overly detailed either and has a nice rich/warm sound that I personally like.
When are you in NYC?? I’m not far from Manhattan, would love to come by and hear the iMod and some of your other stuff.

[srb]

I hope this thread continues, because I would really like to know for what reason the DAC is in the Apple Universal Dock.

When I bought a dock for my 5G iPod, I purposely avoided the Apple dock, because I knew the remote controlled volume, and figured the dock was using the headphone output instead of a true line output.

I bought the Xitel dock because it offered a true passive line out (like previous Apple docks and like my Apple Mini dock).

So all I can surmise is that this dock DAC resamples the analog line out so it can provide volume control in the digital domain?

Which might explain why it doesn't sound so good.  Anytime I have gone through dual conversions (Digital > Analog > Digital > Analog) has always resulted in inferior audio.

[Jade East]

So all I can surmise is that this dock DAC resamples the analog line out so it can provide volume control in the digital domain?

I think that is the way the dock works A>D>A to enable the remote volume. The remote controls the
ipod itself when you adjust the volume the display bar on the ipod changes. It just seems like
a strange thing to do making the dock an active device when they may have been able to get
away with just a hooking up the lineout of the ipod to the output jack on the dock.

[jlh357]

Jade East,
Would you mind telling me what caps you replaced in the Dock? I have been searching high and low for exactly what you did. I know this is an old post but worth a shot.
Thanks