Elevick - Nothing on my iPod is in MP3 - to the mere suggestion of listening to anything compressed that way at all I'd say "why bother". I have a 60 gig ipod that holds my tunes in Apple Lossless. That's about 170 CD's which is certainly better than carrying around a box or folder with that many CD's and sorting through them every time I want to hear something in the car, or through headphones, or in a hotel, or at a friends house. It occured to me that the dock might have the potential for yielding a digital stream, but how do you tap into it other than connecting a laptop?
Marco |
Ed - I was only estimating based upon 600mb/CD in WAV (perhaps I'm off there. I'll have to see how many are actually on my iPod. Compression is about right though. My Alpine car rig is set up with a box that takes the iPod feed from its dock. I was thinking that that box was acting as a DAC since it is taking the feed from the iPod and running into an anlog input on the car deck. So naturally I thought there must be a way. Indeed, your thoughts were as mine: a kinder, more listenable iPod for traveling. My last trip I brought my MicroZotl and ran the analog inputs through the MZ then into a pair of Sony cans. The sound was MUCH better than straight off the ipod, but still left something to be desired in comparison to running the feed off my DAC when running a ALAC at home through the Waveterminal. There are much smaller headamps than the MicroZotl, several being made just for portable use, so yes, that's where my thinknig is going here.
Marco |
Hepl (Hector) - yep, I've done the same using a smaller (250gb) external drive (smaller drive using Apple Lossless format). I use a Waveterminal U24 and am also very happy with the setup. But I was looking for a portable solution that didn't involve toting along the laptop and hard drive. I've tried the Airport Express, but didn't like it in comparison to the Waveterminal route, which works superbly with my DAC.
Audioengr (Steve) - A direct to DAC solution would be great too (as I think you are suggesting with the I2S route), but I'd be happy if I could just get a USB feed to my Waveterminal which would do the S/PDIF conversion. The USB docking dongle won't work as it's the wrong end (and I assume wrong direction) of the USB cable. Do you think it's possible to get a digital feed via USB to go to my Waverterminal, or would that require the chip you mention?
Marco |
Wavelength Audio has USB DAC's Yes, I know about their DACs. There are several companies with USB DAC's but they require a USB input (female). The only dongles cables available from the iPod Dock are USB male. I don't think you can reverse that or use an adapter - someone correct me if I'm wrong. Marco |
Hector - I have an Alpine head unit in the same series, and the same KCA-4201 iPod interface. That was the unit that made me curious if what I'm asking is possible. Alpine makes a nice head unit, but I find the iPod interface to be a bit tedious...don't you? It's still great to have access to such a great variety of music in the car, especially when driving long distance.
Marco |
The only rumor I've heard that indicates any advantage was in the HeadFi forum where someone opined that the op-amp (line-out) in the more recent (video) iPods was slightly improved from the previous versions with a bit more robust output. I don't know if this is true or not. I find the output on my line out to be just barely adequate for listening on the edge of loud. If others were worse than this then I'd say definitely go for a more current version of the video ipod. Other than that, I just went for the most storage capacity, which happens to be a video iPod (60gb). I don't know if any of the current large-capacity offerings from apple are anything but "video" ipods. The only other type of ipods being offered are the smaller units with much less capacity. Unless you are using mp3's, you will be severely limiting yourself in terms of how much music will fit on one. And if you're using mp3s you may as well just glue some nails to the ends of the earbuds and call it a day. Of course if you have to have some pop star's autograph emblazened across the back of your iPod to go with your celebrity sports-star approved basketball shoes, well, then again you are limiting your selection.
Marco |
As an addendum to my ramblings here, I discovered that the problem I was having was with the $99 device that was providing the line output on my iPod. Can't recall the manufacturer, but I believe they were the only ones offering a dock with dual RCA line-outputs. Whatever circuitry they put between the dock and those RCA's was wreaking havoc with my output signal and the music sounded awful. I exchanged it for the much cheaper iDock and went with a $69 Signal Cable silver iPod interconnect and have been happy as a clam since. I recently noticed this mini-system by Monitor Audio claiming to be getting a digital output signal from the iPod lower connection, which it runs to its own DAC and bypassing the DAC in the iPod. If this is so, apparently it is possible...why isn't anyone making a simple cable or converter to do this? |
Nnyc - This has me baffled...how the heck is Monitor Audio able get a bitstream from the docking port of an iPod. I thought there was no S/PDIF output within the iPod. This seems so blatantly obvious and marketable, why hasn't anyone else bothered to do this?!?! I wrote to Vinnie over at Red Wine Audio, and he pointed out that it was interesting that Monitor Audio does not list this as a feature of this unit on their own website. They do mention that it can be used with a computer via a USB connection, and I wonder if that is where the interface is coming into play. Using my computer I can pull the content from my iPod via USB or Firewire through iTunes, have the computer spit out a signal to my converter (a Waveterminal U24) and feed the digital stream from the Waveterminal to an external DAC via S/PDIF or Toslink. I wonder if AudioAdvisor and the reviewer are muddying up the description by leaving out the need for a computer in between in order to feed that digital stream to the DAC? If not, how are they getting an S/PDIF feed from an iPod? Vinnie went on to speculate that they may be using the USB port and a custom converter board (like my external Waveterminal, or an internal sound card for a computer), but added that some software would be necessary to govern that interface. Anyone have any idea how Monitor Audio is doing this? Marco |
I haven't read this whole thread, but I found this thing
www.nyko.com/nyko/products/?i=... Nope, that's just a line output. The digital output would have to be in the form of a single S/PDIF (RCA type connection), or a Toslink connection. Anything that goes directly into an amplification source is using the Ipod as a DAC. With a digital output you would need to go firt to an external DAC. Thanks for posting, regardless. Marco |
Thanks Kana813! That appears to be the real deal. From another thread, compliments of Peter_S and Monitor Audio: The digital/ audio over USB protocol has only just been released to us by Apple in September, which will mean that products in the future may use the digital data stream with local D/A conversion. I imagine once Apple begins releasing products with that protocol they would be very popular among audiophiles. As for the MSBtech device; for $2K you can buy a Mac laptop, an 500gig external drive and have money left over for lots of music. Marco |
Alpine makes a head unit for cars that does not have a CD player. It claims to take the digital output from an Ipod. So it must be possible.
Also, check out Red Wine Audio. They do upgrades on Ipods though not the latest ones. They upgrade the analog section because they claim the DAC is top notch already. One review I read said that the upgraded unit is pretty much reference quality. I have the Alpine iPod interface in my van. I'm not certain it is the one you are referring to but it was the only one they offered when I purchased it - basically a separate black-box interface that connects to the dock of the ipod and feeds the signal to the head unit. It works great (very convenient and sounds OK as far as car stereo goes, but is easily bested by a CD in the same head unit). It does not claim to take digital out from the iPod. It is a $150 accessory (when I purchased it) and I assume it is just taking the line output like all the other inexpensive docking devices for iPod and amplifying the line signal. I am quite sure that the Alpine head unit that I use does not have an internal DAC, nor is the black-box interface contain a DAC itself according to the manual. That Alpine iPod interface has been around for a couple of years now if it is the same one I have. With all due respect to Vinnie and Red Wine, my experience with the Wolfsan DAC in my iPod simply judging from the line output and decent interconnects would certainly not suggest it is a top notch DAC. I have no doubt Vinnie can improve the line-output signal, but that would not improve upon the DACs abilities which are critical in what you hear at the other end. I found the iPod line output to sound 2-dimensional and lacking in dynamics in the systems I've listened to it...fine for casual listening, but sure wouldn't want to sit in front of it for long. I've read some positive words for Vinnie's iMod, but can't recall any giving it the specific praise you mention as "reference quality" digital front end. Is there a new review out recently or any changes to the iMod? Marco |
That is not the unit I mentioned. That is a generation or two old. I went to the Alpine USA site and all I could find there was the same KCA-420i adapter box that I have in my van, which definitely does not extract a digital output from the iPod. Would you provide a link that tells about the newer unit you are referring to? Thanks in advance. Marco |
03-06-11: Gordguide
There is no digital out available via the iPod's USB (or Firewire) ports on the 30-pin connector. There is an analog out at line level there, and it is much superior to the iPod's built-in headphone amplifier, so that is the output of choice for best sound quality on a bone-stock iPod. Man, this thread was resurrected from the dead. I started it back when the task was not possible - As I understood it, that was because of technology or permissions that Apple was not releasing/licensing. That changed with the Wadia 170i I believe around 2007 or so(?). The Wadia unit somehow extracts a digital stream from the iPods connector dock. You can then hook the Wadia's output to a DAC and, Viola - mo betta zeros and ones! Since then, as Larry_S pointed out, others have followed (probably paying the license fee to Apple I'd bet). However the early iPods with FW I still don't believe will work, going back to the earlier point about no digital audio data available in the iPod. Whether USB or FW, the iPod is seen simply as a Hard Drive, not a Digital Audio Stream. I've never seen an iPod with Firewire - just connectors that hook up to the Dock below and yield a USB or FW connection. I don't see your point about the iPod being seen simply as a hard drive - with a digital stream you just need a hard drive with digital audio files on it, and a devise capable of delivering (in this case the Wadia for instance), and translating them (a DAC). What's wrong with being just a hard drive? As I understood it, the only thing keeping anyone from extracting a digital audio stream from any iPod was Apple. |
