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

[omendelovitz]

Originally Posted by YoungClayB

Also keep in mind that this comparison was done based on a 5.5 G iMod with the v-cap dock, which was reported to sound better than the 5.5G iMod with the regular iMod dock, which was reported to sound better than the 4G iMods.

Based on this, I wonder how the 6G line out stacks up against a 4G iMod.

I don't know where you got that from... IIRC, Vinnie said that only the V-cap imod sounds better than the 4g imod; otherwise, he preferred the 4g Wolfson DAC to the 5G's DAC - originally (before ALO), Vinnie told me he wouldn't mod the 5G's b/c its DAC was inferior to the 4G DAC.

FWIW, I recently picked up the 4G imod via ebay (-> Vinnie direct -> me), and although I'm liking it a lot and have noticed improvements in SQ, the improvement wasn't the night and day I expected from reviews here on head-fi. the sound is definitely more refined (I can clearly distinguish b/w 320 and ALAC on 4G iMod, can barely distinguish b/w same on 5g line out), and tonality is fuller and more complete (impressions directly from line out, nothing in between headphones and imod).

Vin, what do you say about 6g line out compared w/4g imod?

Cheers!

[TheMarchingMule]

Thanks for reporting on your findings, Vinnie. Seems like the 6G iPod is as good as it can sound already for the most part, so I'm happy I can keep my 5.5G 80GB iMod and still have people gawking at the weird contraptions it hangs out with. :allteeth:

[Vinnie R.]

Originally Posted by swt61

What I come away with is that if you plan on using an iPod stock you'll be happier with the new 6G.
If you want the best possible sound it won't quite compete with an iModded 5.5G, and it probably wouldn't yield the same benifits from Vinnie's mods, so stick with the 5.5G and wait for harddrive prices to drop.

swt61 is correct! If all you care about having is a stock iPod, the 6G (iPod Classic) is the way to go.

If you already have a 5G/5.5G iMod, I believe you will find that the 6G line-out doesn't sound quite as good. I listened some more. This time, I even tested it using a dock cable with the Black Gate caps with 5.5G iMod and still preferred that over the 6G line-out, but even more so with the Vcap Dock + 5.5G iMod combo. I don't have a 4G iMod here to compare it to, but I know others do and I hope they will post their findings.

Originally Posted by xnothingpoetic

So basically 5g imod> stock 6g> stock 5g

This is correct. Let me add to that:

5G/5.5G iMod with ALO Vcap Dock > 5G/5.5G iMod with ALO dock cable (black gates) > stock 6G line out > stock 5G/5.5G line out

Somewhere in there, the 4G iMod fits and I'm pretty confident that you'll find it between the 5G/5.5G iMod with ALO dock cable and the stock 6G line out.

Originally Posted by manaox2

Anyone want to come to the NC meet on September 23rd to pit my 5.5g iMod and vCap portable dock against their iPod classic using the same ALO line out dock and the Corda Move?

Cool... I am hoping more people will be doing comparisons like this and posting their findings. Thanks!

Originally Posted by Pangaea

This is all good news. I am glad to see apple is paying some attention to SQ. I just hope they have similar workings in the Touch Model.

I agree and I think the 6G line-out and headphone-out shows that Apple has been paying attention (maybe even to headfi and all the iMod posts and about cleaning up these outputs ) to SQ.

Originally Posted by sugarinthegourd

Props to Vinnie for saying the mod is not needed on these units. He could have taken a lot of orders and made a bunch of do-re-mi and I bet none would be the wiser...

Thanks. Yes, believe me everyone, I have received tons of emails and phone calls regarding the 6G and coming up with an iMod. Many people were even asking if they could buy from Apple and ship directly to me for the mod. I would have really loved this kind of business, but it wasn't meant to be

Originally Posted by mirumu

That depends. From what Vinnie is describing, the actual output stage is embedded inside the DAC chip with very few components on the outside. You can't feasibly mod a piece of silicon inside a surface mount chip. This doesn't leave a lot of room for modding and any mods done will most likely be adding components into the signal path which is in itself detrimental and would tend to lead to trade offs. To really mod the classic it would seem you'd want to replace the DAC with a better one and hang a quality output stage off it but that wouldn't be a simple mod and would be prohibitively expensive.

mirumu is correct!

Originally Posted by philodox

Not unless he replaces the DAC they are using...

I wish it were that simple. You see, the legs of a lot of these chips (including the new Apple marked dac) are actually under the chip, and they are soooooooo tiny. Without ultra-precision chip removal machinery, it ain't coming off (at least not without ripping up the pads on the board and cause damage!). The other thing is that this 36-pin (quad array) chip most likely has its own custom pin out, so it is not a matter just swapping the part for a better one (e.g. as if it were an opamp).

Originally Posted by TheMarchingMule

Thanks for reporting on your findings, Vinnie. Seems like the 6G iPod is as good as it can sound already for the most part, so I'm happy I can keep my 5.5G 80GB iMod and still have people gawking at the weird contraptions it hangs out with.

Exactly!

[spraggih]

then is there a DAC modification in the future

you both (mirumu and philodox) make good points. I was just thinking there may be a way to augment/alter the components--- but I am not an engineer (electrical, sound) so maybe there are still possibilities but no probabilities.

[edit] wow - Vinnie posts fast. My post is now even more irrelevant than it was when I first posted it.

Thanks a lot Vinnie! I learned a lot from your posts. As well as from other Head-fiers.

[sugarinthegourd]

5.5G iMod with the regular iMod dock, which was reported to sound better than the 4G iMods.

Izzat so? I hadn't realized that. Like, noticeably better?

[TheMarchingMule]

Originally Posted by sugarinthegourd

Izzat so? I hadn't realized that. Like, noticeably better?

From what I heard (literally and figuratively), it's like this. Assume right now bigger is better. The 4G iMod is an XL, while the 5G/5.5G is an XXL. Little improvements, but noticeable.

[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.


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

[fierce_freak]

I think I read somewhere that the classic uses the same battery as before...it's probably lower power usage that brings extended battery life (and maybe the different dac plays into this).

[itsborken]

Originally Posted by Vinnie R.

I wish it were that simple. You see, the legs of a lot of these chips (including the new Apple marked dac) are actually under the chip, and they are soooooooo tiny. Without ultra-precision chip removal machinery, it ain't coming off (at least not without ripping up the pads on the board and cause damage!). The other thing is that this 36-pin (quad array) chip most likely has its own custom pin out, so it is not a matter just swapping the part for a better one (e.g. as if it were an opamp).

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?

[freethegeek]

Soo....

I just received my box of black gates. Yesterday my package of dock connectors landed. Three days ago the solid silver wire and Neotech copper showed up...and a week ago the switchcraft right angle plugs landed...

..ordered my Super Micro IV last week....

My ear impressions hit the lab for my UE-11's yesterday.

...and here i sit with my thumb up my @$$ trying to figure out which ipod to buy and or also get modded..

Geez... this isn't for the faint of heart.

i guess worst case is i just blew the money on blackgates i won't use any time soon. ..and i'll have some nice components for LODs.