iPod Classic... DAC and output stage info from Vinnie of RWA

[Vinnie R.]

Originally Posted by EFN

But Vinnie, can you please tell us this.....can the 160GB HDD from your iPod Classic be fitted to your 5.5G? or even the batteries are they interchangeable? My interest in 6G iPod is purely on the capability on HDD space and battery, nothing else - because I have heard enough of iModded 5.5G that I am convinced it is hard for other DAP to beat the performance (SQ wise).

Cheers Vinnie

Hi EFN,

While I haven't tried it, I am fairly confident that the 160GB drive will fit in the 5.5G, 80GB iPod. They use the same ZIF connector at least
I'm not sure if having an extra 80GB will cause a problem for the 5.5G... hopefully not. The 6G I have here is only an 80GB, so I can't test this.

Regarding the battery, I *think* they are the same model... the 6G gets better life because its design is more power efficient.

Viinie, yet again you have been a great help to the community. Please accept our thanks for your R&D.

Thanks, and you all are very welcome... you've guys have been very good to me and there are a lot of loyal iMod customers here. The least I can do is let you know my findings, and to let you know upfront that there is no point in modding the 6G. Different animal...

Thanks again,

Vinnie

[Vinnie R.]

Originally Posted by itsborken

Vinnie, any chance of breaking out the digital feed before the onboard dac and shooting it out to an external jack so that we could use a D1 in Optical/spdif/coax mode to do the DAC work?

The digital feeding the dac is I2S (three separate lines), so that won't do you any good. There is no SPDIF to be found anywhere in ANY of the iPods to date (believe me, I've looked very hard for it!).

This company actually mods the 5G/5.5G by grabbing the I2S before the dac, sending it out of the unit and into a dock that has a boad on it that converts the IS2 to SPDIF (optical, coax) and AES/EBU. However, its $2000 :blink: (http://www.msbtech.com/products/iLink.php)

[Chef Medeski]

Originally Posted by EFN

Vinnie, yet again you have been a great help to the community. Please accept our thanks for your R&D.

From what I can understand, iPod 6G is already quite good (both from the headphone out and Lineout) that modding it into an iMod would be pointless because there's no cheap SMT caps to remove and replace. The foundation of both iMod 4G and 5G is quite simple, get rid of the "degrading" elements in the DAC output stage to get the cleanest signal possible, and substitute the cheap caps with better quality ones. Apparently 6G iPod does not work this way.

So, if you're keen on keeping your DAP stock, iPod 6G is a good solution. But if you want to tweak (or get tweak) for "better" SQ, sticking with 4G and 5G iMods will be a better choice.

I am okay with this.

Or maybe corrected me! The HD would fit. And that would increase the battery life significantly cause I have heard the new HD is much more efficient.

But Vinnie, can you please tell us this.....can the 160GB HDD from your iPod Classic be fitted to your 5.5G? or even the batteries are they interchangeable? My interest in 6G iPod is purely on the capability on HDD space and battery, nothing else - because I have heard enough of iModded 5.5G that I am convinced it is hard for other DAP to beat the performance (SQ wise).

Cheers Vinnie

The 160GB HDD has a different interface, so you will need an adaptor that to my knowledge does not yet exist. I thought as wel it was IDE but eivdently they changed the interface. As for battery. The battery in the 6G is actually the exact same one as the 5.5G. There was not enough room for a larger battery and last time I checked, battery technology has not changed significantly (and after a breakdown it was discovered it was the exact same battery). The increased efficiency seems to be due largely to the much more efficient HD. Also the screen seems to be new. Those are the two biggest drawers of power in an iPod. To triple the battery life I think both would need to be changed which have.

So unfortunately, no and no. Size and battery life are solely for the new iPod. My advice go with a 40GB iPod Phot iModded and stick in a 120GB HD. Close size, good battery, but about ten times thicker.

So apparently Vinnie has corected me. The HD would fit since its ZIF as well. And it would significantly increase the battery life, since the HD is much more efficient. So I think that would be a worthy mod.

[mirumu]

Originally Posted by Chef Medeski

The 160GB HDD has a different interface, so you will need an adaptor that to my knowledge does not yet exist. I thought as wel it was IDE but eivdently they changed the interface.

Supposedly it's a CE-ATA interface. I don't know what effect this would have on compatibility or if the interface pinout is any different from older models. CE-ATA is not a new standard so it's possible previous iPod hard drives have used it too in which case a swap should work. There is still the possibility of firmware limitations but I don't believe Apple has been doing anything like this to date.

[trose49]

Originally Posted by xnothingpoetic

What I read is that the 6g without v-caps, sounds almost as good as a 5g imod w/ v-caps.

I must be reading a different post! I did not get that! Vin said all he had to compare was the 5.5>V-Dock vs line out of 6 G and the 6G was thinner in the bottom and not as "sweet"

We need to do a 5.5g lineout to a 6G lineout comparison to really know whats going on here!

Gotta go baseline to baseline assuming the V-dock is a bonus.

[htbyron]

Many thanks, Vinnie! Based on your analysis and report I bought the Classic 80GB on my way home today. I just finished syncing it and will listen tonight through the HO. :rs1smile: I will also look for a decent (but not extravagant) LO dock to listen with an amp and decide whether there is significant improvement there. I had not planned (initially anyway) to go for the additional imod, and your forthright report convinced me that this new model is a substantial improvement as stock from the 5.5G I was also considering. You are da man! :580smile:

[trose49]

Originally Posted by htbyron

Many thanks, Vinnie! Based on your analysis and report I bought the Classic 80GB on my way home today. I just finished syncing it and will listen tonight through the HO. :rs1smile: I will also look for a decent (but not extravagant) LO dock to listen with an amp and decide whether there is significant improvement there. I had not planned (initially anyway) to go for the additional imod, and your forthright report convinced me that this new model is a substantial improvement as stock from the 5.5G I was also considering. You are da man! :580smile:

Im more confused then ever now! :blink:

Because the Apple routing is shorter and does not seem worth modding to try to improve upon doesnt mean is sounds better than a stock 5.5G does it?

If the Dac is not as good what difference does the path make?

????

Vinnie Please reply!

[mirumu]

Originally Posted by trose49

I must be reading a different post! I did not get that! Vin said all he had to compare was the 5.5> vs line out of 6 G and the 6G was thinner in the bottom and not as "sweet"

He did say the 5.5>V-Dock was still better like you're describing, I think it's just it wasn't the huge difference that some were expecting. It would appear that with the iPod Classic Apple has closed the sound quality gap quite a bit. To some the difference may be small enough that they don't see the iMod as a necessity. The iPod is still just a portable player and in it's default guise it isn't a replacement for a quality home CD rig. To those who have the cash and still want to push the boundaries of what an iPod is capable of, the 5.5G iMod + V-Dock is still an option. People should compare and see for themselves as manaox2 and Vinnie were saying earlier.

[trose49]

Originally Posted by mirumu

He did say the 5.5>V-Dock was still better like you're describing, I think it's just it wasn't the huge difference that some were expecting. It would appear that with the iPod Classic Apple has closed the sound quality gap quite a bit. To some the difference may be small enough that they don't see the iMod as a necessity. The iPod is still just a portable player and in it's default guise it isn't a replacement for a quality home CD rig. To those who have the cash and still want to push the boundaries of what an iPod is capable of, the 5.5G iMod + V-Dock is still an option. People should compare and see for themselves as manaox2 and Vinnie were saying earlier.

I agree with the self compare. But if the path is too short for Vinnie to shorten but the Dac is not as good seems like an imod would still sound better than a 6G even without a V-Dock.

Seems Vin did not try this because he was using the V-dock and not an iMOD cable>amp combo.

[mirumu]

Originally Posted by trose49

Im more confused then ever now! :blink:

Because the Apple routing is shorter and does not seem worth modding to try to improve upon doesnt mean is sounds better than a stock 5.5G does it?

If the Classic's output stage more closely resembles the 1G Shuffle (Apple's best output stage so far) as Vinnie suggested then it theoretically should sound better than the stock 5.5G. Hopefully someone with an un-modded 5.5G can compare to either verify or deny this.

Originally Posted by trose49

If the Dac is not as good what difference does the path make?

We don't know anything about the DAC and probably never will as it's an Apple branded part. It may very well be the same DAC inside. It could be better, it could be worse.