|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
12.118.69.178
In Reply to: Another Vinyl to iPod question (repost from Vinyl Asylum) posted by roadie on October 27, 2004 at 08:31:03:
I have been unable to get My iPod to play back anything greater than 44k/16 bits.I have loaded 24bit/44k, 24bit/88k AIFF files to my hard drive (vinyl recorded on an Alesis Masterlink). I then transferred them to the iPod. Won't play.
Converting 24/44 files via Apple Lossless Compression results in a file described as 16/44. Plays without problems off hard disk (in a Apple G5 dual 1.8 computer) or iPod.
Then tried applying Apple Lossless to the 24/88 AIFF files (which, interestingly, when loaded on the hard drive show up as 24/65k (?)- a separate issue that I would love to understand- they play back via the computer D/A converters normally). This results in tempo/pitch shifted music, i.e. Apple Lossless as far as I can tell doesn't work with sampling rates > 44k.
My questions/struggle has been obtaining/managing adequate resolution files on my hard drive. I haven't been troubled by the sound quality of my 24/44 > 16/44 via ALC as rendered by the iPod.
BTW, as relates to the other threads re. USB, SPDIF, etc. I have ordered a Benchmark DAC1, planning to connect it to the computer via TOSLINK (and hoping that the claimed, and perhaps demonstrated, jitter reduction of the Benchmark will result in a nice combination). I have been apprehensive re. an electrical connection between the computer and the outside world since having a hum/ground problem that I couldn't fix with an internal Lynx card.
I'd love to here others' experiences/ideas as well, though I am leaving town shortly until tomorrow evening. Good luck!
Follow Ups:
Bill,I think it has too do with the dac in the iPod. I think it is only capable of 48/16, I am looking for my schematics too see if I can find that out... but my office is a mess.
AHHHH Oh well... each of the last few iPods have had different dacs but I think the top output is 48/16. Though I have not tried to convert anything to 48/16 it might be worth a try.
I suspected that was the case. The iPod (hard drive) seems to store/handle the files fine, just not replay them via the DACs.Now, if I could just figure out why my 24/88 AIFF files all store in iTunes as 24 bit/ 65.535Khz. Any ideas based on your advanced technical knowledge/understanding?
Thanks,
Bill,Bill as a programmer I can only assume that it is an unsigned integter of 16 bit quantity and therefore the maximum it will take would be 65535.
Seems unlikely though as I did some work with iTunes and Firewire dac and there it was 2 channel and 24/192 but I never actually look at the data going out much as the circuit that Apple/Oxford Semiconductor was pushing was complicated and high in jitter.
I know Atkinson is pushing higher rates in some other applications, why not ask him.
nt
This post is made possible by the generous support of people like you and our sponsors: