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Is it possible to rip HDCDs using iTunes such that you get the extra preciouss bitses? I understand that you can rip it as a regular CD, but HDCD is 20-bit, right?

If iTunes can't do it, is there a way to rip HDCDs while preserving the "HD" portion?

EDIT: Assume a Mac, but I also have a PC.

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As long as its bit perfect the light should turn on... you ca't dither/replaygain/eq/tweak it in any way. If it's doing that as a default setting then it's not going to work. But I don't use itunes to rip stuff so I'm no expert either on what to do.

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It depends on what you want to do, Monkey. If you want to run it through an HDCD DAC, then yes, just rip it lossless and run it out a bit-perfect digital out of whatever computer you use.

But if you want to decode it (it's just a filter), then you'll need to track down hdcd.exe. The way I do it is rip it to .wav; run it through hdcd.exe; then convert it to whatever it is you want to do (apple lossless, etc.).

Undecoded, it's 16-bit. Decoded, it can be anything from 18 bit to 24 bit (I've read 18, 20, and 24, don't know why, haven't done the math). They're not adding information, it's just the representation that's different. The 16-bit representation happens to be compatible with 16-bit audio, but is not the "perfect" representation of the music.

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I've used iTunes to rip 4 HDCDs perfectly. At least, the HDCD indicator on my DAC lights up when I play the files.

x2, in fact I thought that was one of those much discussed informal tests of bit-perfect output - ripped HDCDs show on outboard DACs.

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It depends on what you want to do, Monkey. If you want to run it through an HDCD DAC, then yes, just rip it lossless and run it out a bit-perfect digital out of whatever computer you use.

But if you want to decode it (it's just a filter), then you'll need to track down hdcd.exe. The way I do it is rip it to .wav; run it through hdcd.exe; then convert it to whatever it is you want to do (apple lossless, etc.).

Undecoded, it's 16-bit. Decoded, it can be anything from 18 bit to 24 bit (I've read 18, 20, and 24, don't know why, haven't done the math). They're not adding information, it's just the representation that's different. The 16-bit representation happens to be compatible with 16-bit audio, but is not the "perfect" representation of the music.

Thanks Dusty. So the 16-bit might not be "perfect," but it would still be discernible from the "regular" redbook (assuming one can tell the difference)?

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Only because usually more care was put into the mastering, but that's not a guaranteed to be the case 100% of the time. It's just that, if the artist is putting that much money care into their master that it's HDCD, then they usually do the same with the rest of the mastering process.

So if it's the same exact master, then the only difference would be the slight compressing at the top and bottom of the dynamic range (it's rather like dolby, only an order of magnitude or two more subtle, because they can do that in the digital realm).

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Yeah generally the only gratification I get with regards to the light is the fact that there's a sweet light that is now on and now I know the thing was mastered with the pacific microsnics model 1 or 2 which regardless of hdcd are some of the best adc ever from my understanding.

HDCD itself is no more special than any other format hirez or redbook to my ears... even if there are supposed technical benefits.

The most important thing for me in your case is that likely if the light turns on then that means it's using the pmd200 filter (Possibly only the PMD200 filter) versus Esoterics.. its mostly a diagnostic thing.

I've never gotten it to turn on before but I also never really tried as it never occured to me until testing it prior to shipping it out that I could do it and JP had the remote at the time (necessary to tweak settings). In fact I didn't even know that it had an hdcd light if that's what it is. (It has a little hdcd marking or whatever on the display which I assume lights up). Lucky you will have both the remote and the manual(s) service and normal to figure out how to get that bugger on ;p

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I had seen a thread on HDCD before (and I thought it was on hdcd), but it wasn't anywhere near as useful as that one. Especially having examples cited, now I can go reverse engineer it for myself.

And I should add a qualifier re: hdcd.exe -- I'm not sure he does the different cases iterated in that thread correctly -- I'd be curious to know for sure. I think he only does the one most complex case, which would mean he's decoding the others incorrectly.

Another way to do it would be to rent the Pacific Microsonics Model One or Model Two (it is one of the few devices that will decode entirely within the digital realm), digitally capture the results (I was going to use the Alesis Masterlink), and then use that (.wav files or whatever) as the input to your iTunes library.

Edited by Dusty Chalk
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As with everything else, I think the hdcd indication really just is a way of saying "we tried to make it not suck", since music doesn't need more than 16 bits once it's been mastered.

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As stated before, if you have a HDCD capable HDCD, and you can bit perfect rip, you get to light up the HDCD light :)

If you don't have a HDCD capeable dac, you can do on the fly expansion in squeezecenter using hdcd.exe, or preprocess using hdcd.exe , or use the HDCD plugin for DBPoweramp.

Helps if you have a 24bit capable DAC for the expanded output.

MeridianWiki - Handling HDCD

Or just use expectation bias in you favo(u)r, and think to yourself before listening, that "man, this HDCD special sauce really is the shiznit" :)

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16 bits allows for 96db signal to noise. That's enough range to discern a conversation next to a jet. Music doesn't cover more than that.
It's more than that. It's not just the maximum signal vs. the minimum signal, it makes the whole signal more accurate. Resolution increases accuracy in the "vertical" direction (looking at a graph of the signal), raising the sampling frequency increases accuracy in the horizontal direction. If you believe it's all in the sampling frequency, that's like increasing the resolution on just the "X" on an x-y axis.

So it should approximate the original analog signal more accurately.

And yes, I'd be happy to lend you my personal reference, but I don't think Alan Parsons Project's I, Robot does anything for you, whereas there are some very nice jazz and blues stuff on Classic Records that I don't have that you might be more interested in. I could also lend you some classical, of course...

Edited by Dusty Chalk
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