jeff3000

I am getting confused about which head units from alpine (or other brands)
actually get a digital signal out of an ipod and send it to the internal DAC .
I am reading a lot a different opinions on this.

From the alpine website, it seems that the w505's, ida's and ixa-w404
work that way but I have heard different stories.

I want a HU that could sent the digital information straigh from the ipod
through the head unit and then through an optical cable staight to my
processor(soon to be an pxa-h900 with dead display) to take advantage
of the DAC's of that unit

jeff3000

well, I just spoke with alpine and apparently all of their head units made
for ipod actually bypass the ipod dac and use their own.

Problem is, the tech told me that if I have a processor with an optical connection, the head unit will still send an analog signal to the processor. It supposivly does that even when playing a cd in the HU rendering the use of any good processors own dacs completely useless.

Apparently, the only time the processor will use it's own dacs is if you are
listening to a dvd audio with surrond sound.

Natban

So Jeff, you mean that with a CDA-9887 connected to the ipod via full seep cable (kce-422i) that a digital signal is sent into the HU and processed by the Burr Brown 24bit DAC? I'm in the process of try to figure all this out for my new deck.

Denonite

iTrader: (1)

not too sure about that...as far as i know, the only unit that actually bypasses the ipod's internal dacs is a home audio unit from Wadia. Unless this is a new feature, I don't think the regular dock conector hook up bypasses the internal dac. Wadia somehow tricked the ipod into sending out the digital info. Again, that's up to about 6months ago when i looked into it. Here's a link to the product:

Wadia Digital

RomanticMoments

I'm struggling to figure out how the Wadia product sends digital signals via ANALOG connections........ I also have a hard time figuring out how any deck can send analog signals via a digital medium..... The deck "bypasses" the iPod's DAC because the iPod is designed as such, not the deck. The deck has to be able to take the iPod's digital signal and convert it, same as a CD, same as any digital signal. A speaker's operation is analog to begin with. To send the newly converted analog signal through a digital connection (i.e. optical), it would have to convert it from analog to digital.... It's tough to send an AC voltage via a piece of glass designed to transmit pulses of light.... The proper question to ask would have been if the deck converts the signal back to digital or if it simply passes-through the already digital signal it's receiving when you have a processor or other digital receiver of some kind connected. This is very serious audiophile stuff though, if you're trying to avoid reconversion, and without knowing what the full system is, I'm not sure if it's going to be worth it.... Plus, at that level, NO audiophile would use an iPod for it's source, hence why companies like McIntosh only offer CD recievers for car audio

Denonite

iTrader: (1)

The wadia has a co-axial s/pdif output for digital signals....it looks like a regular rca connector, but it's digital (electrical pulses). As far as the other conversions and re-conversions are concerned...apparently there's lots of debate as to what the ipod does and does not do, and i'm as confused as everyone else. I would assume that the usb hook up is a digital stream and that it would bypass the dac in the ipod, so i guess the alpine and other head units are using a pure digital signal that they can send via optical, co-ax, or whatever else to the processor's dac. Ofcourse, that's my assumption, and we all know what that can make you. From what i've recently learned, the ipod does have a digital output on the dock connector for use with a/v systems, but it requires special decoder that has to be purchased from apple. Apparently that's the output that wadia uses. Again, i'm not an expert on this but that's what i've gathered with further investigating.

Natban

Wadia, Shmadia. I'm looking at these Alpine IDA-X305 decks and Alpine says that they've worked with Apple to design these and that hardware plus software allow Alpine to recieve a digital signal from the Ipod and use the IDA's 24bit Burr Brown DAC.

But about the Wadia, I don't know, I've not done any research on them.