Expensive CD transport vs cheap DVD player
- Thread starter norliss
- Start date
sq225917
Bit of this, bit of that
I'm still not sure what point you're trying to make. I'm not familiar with the device or it's intended use, you'll have to spell it out for me.
Are you suggesting it's an agnostic 'transport' equivalent or a dac with measured performance beyond audible differences?
I can't tell because there's no measured performance specs. Come back with a suite of numbers, for snr, thd+n, FR, jitter, 32 tone imd and output impedance and maybe there's a discussion to be had.
Are you suggesting it's an agnostic 'transport' equivalent or a dac with measured performance beyond audible differences?
I can't tell because there's no measured performance specs. Come back with a suite of numbers, for snr, thd+n, FR, jitter, 32 tone imd and output impedance and maybe there's a discussion to be had.
music fiend
life lusting
My point is that in theory DACs may be transport agnostic but in practice they seldom are. Using a Chromecast Audio as a digital transport into a good DAC can be enlightening, as the end result IME leaves a lot to desire vs what one can get with an average digital transport, such as a Bluesound Node.
Sorry, I really don't look keenly at measurements when it relates to digital transports and DACs, as almost all have superb measurements. Alas, they don't all sound superb to my ears.
Sorry, I really don't look keenly at measurements when it relates to digital transports and DACs, as almost all have superb measurements. Alas, they don't all sound superb to my ears.
sq225917
Bit of this, bit of that
Optical has always been shit, very few implementations pass spec, either send or receive ends, and wireless protocols, well.
Spdif and aes are remarkably robust protocols, you can send cd res spdif over almost any bit of old wire and it arrives intact.
Similarly, you have to be negligent to f-ck up usb with an xmos card at the receiving end.
Spdif and aes are remarkably robust protocols, you can send cd res spdif over almost any bit of old wire and it arrives intact.
Similarly, you have to be negligent to f-ck up usb with an xmos card at the receiving end.
Fourlegs
Trade: WAVE High Fidelity digital cables
One of my Profs at university would remind us students that Standards are the minimum to which one is permitted to stoop.
Salamander
pfm Member
But I wonder if he had 'musical' standards? Would he use a dac that cannot differentiate between sources at different price levels?
tuga
Legal Alien
But I wonder if he had 'musical' standards? Would he use a dac that cannot differentiate between sources at different price levels?
I thought the goal of a DAC was to accurately reproduce the differences in the audio signal.
Humans can differentiate, not DACs, but they're not always able to.
Of course S/PDIF being a flawed inerface it is possible to mess things up at both ends but what we're saying is that better interfaces at the DAC end will show negligeable differences between transports/sources.
Salamander
pfm Member
So the first half of your post you are agreeing with me.
I don't no why S/PDIF is a flawed interface, I've used it for many years (RCA and BNC) and it as always sounded fine. We are using AES/EBU at present and this is able to show up differences between sources and, would you believe it, cables.
Salamander
pfm Member
I don't believe our dac's are 'flaky' with any source. Let's hope your technical term of 'flaky' is interpreted the same by both of us.
paulfromcamden
Baffled
Can anyone explain to me in laymans terms why one transport that can read a CD bit perfect might sound different to another?
hifinutt
hifinutt
Geoffreybombom
pfm Member
Jitter, component quality, transport quality to name just three
paulfromcamden
Baffled
Thanks for the video Phil. So he's suggesting that a decent buffer is needed to avoid jitter. Makes sense.
The $70 Pioneer DVD player linked to above seems to have a 2 sec buffer and puts out an almost perfect square wave. If it's all about buffering surely that should sound the same as the $7000 PS Audio transport?
paulfromcamden
Baffled
Yes. My takeaway was that clocking is tricky and a hefty buffer solves potential problems with jitter. I may be simplifying a bit - I did say in laymans terms : )
edit: and I should point out that I'm pretty agnostic about all this stuff - the fact CDs work at all seems pretty crazy to me!
sq225917
Bit of this, bit of that
@Bodhi, that's a claim certainly. Let me counter with, where's the proof that it results in a reduced read error rate? Any measurements to show that lots of cnc alloy beats the rubber bumpers on a cheaper transport?
My numbers might be off a little, ISTR that the red book standard specifies no more than one lost sample per 12 hours of playback.
People misunderstand how data is packed and read off cd. They aren't contiguous samples one after another, they are spread about on the surface of the disc, all read together, buffered and then interleavened, each data block is then checked against a check sum to assure the contents are right, only if all that fails is a sample interpolated. And that's even before it gets off the servo board.
Look up https://en.m.wikipedia.org/wiki/Cross-interleaved_ReedāSolomon_coding for a very top level view.
Every sample goes through this process, all the time, with multiple layers of redundancy.
if a cd player sounds more analogue that's because what happens in the transport and dac is more perfectly digital, not less accurate digitally, which would just introduce errors, noise, and distortion to the playback. And of course the design of the output stage, because that's ultimately what you're listening too as digital has been a done deal for decades if the designer follows the rules.
My 30 year old audiolab cdm 8000 transport with philips cdm9 pro swing arm mech sounds just like my vinyl, apart from the pops n ticks, slightly wavering speed stability and mono'd bass of my vinyl playback, where the mastering allows. And my vinyl setup is 15x the cost of my dac n transport.
That's to say, my vinyl strives for the solid timing and dynamics of cd and my digital strives for the effortless grace and musicality of my vinyl.
My numbers might be off a little, ISTR that the red book standard specifies no more than one lost sample per 12 hours of playback.
People misunderstand how data is packed and read off cd. They aren't contiguous samples one after another, they are spread about on the surface of the disc, all read together, buffered and then interleavened, each data block is then checked against a check sum to assure the contents are right, only if all that fails is a sample interpolated. And that's even before it gets off the servo board.
Look up https://en.m.wikipedia.org/wiki/Cross-interleaved_ReedāSolomon_coding for a very top level view.
Every sample goes through this process, all the time, with multiple layers of redundancy.
if a cd player sounds more analogue that's because what happens in the transport and dac is more perfectly digital, not less accurate digitally, which would just introduce errors, noise, and distortion to the playback. And of course the design of the output stage, because that's ultimately what you're listening too as digital has been a done deal for decades if the designer follows the rules.
My 30 year old audiolab cdm 8000 transport with philips cdm9 pro swing arm mech sounds just like my vinyl, apart from the pops n ticks, slightly wavering speed stability and mono'd bass of my vinyl playback, where the mastering allows. And my vinyl setup is 15x the cost of my dac n transport.
That's to say, my vinyl strives for the solid timing and dynamics of cd and my digital strives for the effortless grace and musicality of my vinyl.