I do know that the IPC now uses Cirrus DAC chips, as opposed to the older WM chips.
From what I read on the Cirrus site, this specific DAC has capless output, which explains why there are no DC filter caps mod as found with the slightly older "Video" iPods.
However I noticed something. From the structure picture that Cirrus has provided with their PDF docs, it seems that there is a DSP built-in within the DAC but before the actual converter circuit, followed by an output signal that is amped within the DAC also, which could explain why the EQ applies no matter what, even if you have a Wadia iTrans.
So right now, it looks like the iPod line-out is not a 100% pure, unamped, untreated signal. It is amped, it can be EQ'd.
This all started when I realised that the line-out jack (literally marked "LINE OUT") on my CD player is extremely quiet, and is not affected by bass boost or virtual surround or any sound effects... as opposed to the iPod line-out.
So... to "mod" the iPod Classic, one has to replace the entire DAC chip, it would seem. Even if we are able to find another chip that has the same pins and the same regulations (power draw, etc), I don't know what effect it will have on the Pod.
Just wanted to share my discoveries. Maybe someone found out about all this long before me
still.
PS: To get the documents, go to Cirrus Logic website, click D/A converters, and click the CS4334 one. Typing on handheld device, can't type entire address.
Please comment, discuss, talk, share.
EDIT: Made 500+. Post count counts not, remember.
From what I read on the Cirrus site, this specific DAC has capless output, which explains why there are no DC filter caps mod as found with the slightly older "Video" iPods.
However I noticed something. From the structure picture that Cirrus has provided with their PDF docs, it seems that there is a DSP built-in within the DAC but before the actual converter circuit, followed by an output signal that is amped within the DAC also, which could explain why the EQ applies no matter what, even if you have a Wadia iTrans.
So right now, it looks like the iPod line-out is not a 100% pure, unamped, untreated signal. It is amped, it can be EQ'd.
This all started when I realised that the line-out jack (literally marked "LINE OUT") on my CD player is extremely quiet, and is not affected by bass boost or virtual surround or any sound effects... as opposed to the iPod line-out.
So... to "mod" the iPod Classic, one has to replace the entire DAC chip, it would seem. Even if we are able to find another chip that has the same pins and the same regulations (power draw, etc), I don't know what effect it will have on the Pod.
Just wanted to share my discoveries. Maybe someone found out about all this long before me
still.PS: To get the documents, go to Cirrus Logic website, click D/A converters, and click the CS4334 one. Typing on handheld device, can't type entire address.
Please comment, discuss, talk, share.
EDIT: Made 500+. Post count counts not, remember.
