@Black Elk Well, the Audiolab 6000CDT transport won't de-emphasise discs with pre-emphasis, just had it confirmed by them today ☹️. Still waiting to hear from Cambridge Audio but its a bit immaterial now because if the transport can't decode the signal properly it doesn't really matter if the amp's DAC can or can't.
Sorry to hear that. There are a few workarounds, of course, but it is disappointing that a device that is termed a 'CD transport' does not support a feature of the CD specification, but then so many players/transports no longer support things like Index Points either.
But...it's not the transport's job to de-emphasize, it's the DAC's. If it can't read/pass the PE flag to the DAC, that's a problem, but it *shouldn't* be doing any de-emphasis.
Correct, which is why I wrote: @Magic Mountain will have to inform us of what he specifically asked Audiolab. If he has asked the wrong question, then a follow up may be needed to clarify, but it would not surprise me if the feature is not supported.
My point is a transport *shouldn't* perform any de-emphasis, so there's nothing to be sorry about or disappointed by. Not passing flags in the output is another matter.
I interpreted @Magic Mountain's follow up to mean the transport does not insert the flag in the SPDIF stream, since that is what I asked him to ask Audiolab. We will need him to confirm whether that is what he asked Audiolab, and whether his response above mixes things up a bit. He knows the de-emphasis takes place in the DAC, since that is a secondary matter he is taking up with Cambridge.
I've gone back to the Audiolab man to double check. I was perhaps a bit vague and simply asked if the unit could deal with pre-emphasis CDs. The customer help guy reported back from the technical department sayibg it couldn't deal with it. This time I have asked them to confirm and have lifted Black Elk's text from his previous posts so they know exactly what my query is. Now we wait.
I have the 300. Via analog out it does SUBQ/TOC. 303 is pretty much the same so it should. Any dedicated cd player should have no issues with pre-emphasis using the analog's. Now via optical/digital is anyone's guess. Some will detect TOC, but not SUBQ. Universal players are a crap-shoot.
Are there players with both analog and digital outs that detect/decode PE in the SUBQ for analog out but not digital out? Because it seems like it would be either both or neither.
I haven't come across any player that caught the SUBQ flag via digital out. It's why I went looking for a CD player with a good analog converter.
That doesn't make any sense, especially when in most CD players the analog and digital outputs work simultaneously. The player doesn't know which you are listening to. Like @lukpac says, it must work the same for both.
That's why I think it's the internal DAC catching the SUBQ flag. Table of contents location yes. None of my players have been able to see/detect SUBQ via digital/optical. @George P Will your Ruby catch Sub via digital? Have you messed with it?
But the transport should be sending the same digital data to both the internal DAC and the digital output. It’s not as if there’s a differentiation in the digital data between PE coming from the TOC and PE coming from the subcode. Hence: confused.
That's not a contradiction, is it? It is absolutely possible that two things happen simultaneously yet in different ways. And obviously a CD player doesn't "know" anything. AFAIK, decoding CD pre-emphasis, as it was originally defined in the CD standard, is/was something that happens during digital-to-analog conversion, so it makes sense that it is applied via analog output and not via digital output. A purely digital equivalent to the de-emphasizing process is offered e.g. by certain software tools, but those are more recent inventions and not something intended or planned for by the CD standards that originally defined the process. Or that's what I think.
Should is the key word I would of stayed with Oppo if SUBQ location would of been detected -Analog or digital.
But that makes sense: the transport doesn't pick it up, so neither the analog or digital outputs handle it correctly. But if the transport picks it up, it doesn't seem to make sense that it would be handled correctly on the analog output but not the digital output. The internal DAC should be getting the same digital stream that's being sent out via the digital output. And that stream either should or shouldn't have PE, depending on if the transport picks it up.
I have no idea Luke. This tech/science/math is beyond me. I just know what worked and what didn't. Some cd-rom drives are able to scan/detect SUBQ flag location, others can't. No idea why.
Again, though, that's a transport issue. You're saying some players: - correctly decode PE via the analog outs regardless of if it's in the TOC or subcode - correctly send the PE flag via the digital out if it's in the TOC - *don't* send the PE flag via the digital out if it's in the subcode ? Which ones?
From my experience, correct on all. Dedicated CD Players -Correct EQ applied-Analog out both/Digital-TOC/SUBQ none
Yes, it is a contradiction. As @lukpac has been trying to point out, the only way a DAC (internal or external) can know about the presence of pre-emphasis is whether the pre-emphasis flag is set in the digital data stream it receives from the transport. The raw data read off disc has to be unscrambled to undo Eight-to-Fourteen Modulation, channel offsetting, data interleaving, etc. and undergo error correction if needed. Only when the transport has sufficient data in memory can it determine the contents of the P and Q subcodes. If the pre-emphasis flag is detected, it is inserted in the data stream that is sent to the internal DAC and to the SPDIF digital output.
