There is no error-correction in Ethernet digital-audio transmission… there is buffering, but no error-correction schemes implemented in UPnP/DNLA… USB protocol provides signaling from the USB receiver to inform the USB transceiver controller as to when it is ready to receive more packets… A DAC does not know anything about the data it receives beyond what is provided by the receiver interface bus controller… The DAC clock topology is asynchronous of the transmitted data clock which correlates the sample-rate of the signal… It only works on the interpretation of the signals it receives, whether corrupted or not…
Of course, there is no need to have error correction mechanism at UpNP level as this is handled at the layers below: IP in that case. So, data reaching UpNP are correct by nature, thanks to the underlying protocols.
DAC then use this “perfect” stream of bits to recreate the original analog samples by using a clock that should be free from some form of jitters. And then, there are potential sources of interferences that can pollute the analog signal.
To answer the original question, then in my experience I would have to say no.
Too many vagaries between hard/software manufacturers for the system to be truly reliable (imo).
A direct USB connection would appear to offer the best ‘stress-free’ solution.
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USB (simple):
Audirvana → system/USB I/O bus controller/transceiver → cable connection interface transition → cable architecture/signaling → connection/interface transition → DAC
Ethernet (simple):
Audirvana → system/Ethernet I/O bus controller/transceiver → cable connection interface/transition → cable architecture/signaling → cable connection/interface transition → router/switch → (potentially corrupted data output for multiple reasons) → connection transition → cable architecture/signaling → connection/interface transition → DAC (The DAC only acts on the digital-audio data-signal it receives, which can be corrupted for a number of reasons, prior to delivery to the DAC archtiecture.)
Digital-audio signals are analog…
What you are ignoring is the layer (SW or HW layer) in charge of ensuring a correct transmission of data (any data).
On Ethernet connection, you have the physical layer (Managing potential collision on the ethernet cable), the link layer (ensuring point to point transmission) and the transport layer (ensuring correct transmission from an ethernet address to another one).
So, at the end, providing that the communication is technically feasible (both parties are up and running and all intermediate devices and cables are in a good shape), data are correctly transmitted.
Data that contain audio sample are then correctly transmitted from the source to the DAC.
And then comes the process to rebuild the original audio signal that is the main purpose of the DAC.
And about your last statement ‘Digital-audio signals are analog…’, I’m sure of what you mean by that.
Thing is that:
- Digital audio signals are representation of an analog one (Resulting from sampling)
- Digital audio signals (Bits) are carried through cables as any other data
- Data (bits) are transmitted through modulation of a signal
- Digital audio are then converted to analog audio by the DAC
This is only true if the signal waveform has not been corrupted in the transmission scheme…
A ‘Bit’ is equal to a ‘voltage’ potential that subsequently opens or closes a ‘gate’… a ‘bit’ is read by the comparator that produces a Positive (+) “ON” or Negative (-) “OFF” voltage stream pulse that contains the ‘coding’ of the digital-audio data that was created using the same process of conversion in ADC (Analog to Digital Conversion) which is really a misnomer, and in the Digital to Analog Conversion, to a voltage that can drive an amplifier, typically an op-amp employed in the DAC output circuit topology… They are all analog signals represented by modulating voltages being interpreted differently by various analog electronic devices for different reasons and fundamental applications in an electronic circuit design and topology… The only time a ‘bit’ is not a voltage is when it is stored on physical media such as an optical disc, a punchcard, or some other mechanical means of storing digital code.
From the Wikipedia article: “Bit”
Physical representation
A bit can be stored by a digital device or other physical system that exists in either of two possible distinct states. These may be the two stable states of a flip-flop, two positions of an electrical switch, two distinct voltage or current levels allowed by a circuit, two distinct levels of light intensity, two directions of magnetization or polarization, the orientation of reversible double stranded DNA, etc.
Bits can be implemented in several forms. In most modern computing devices, a bit is usually represented by an electrical voltage or current pulse, or by the electrical state of a flip-flop circuit.
For devices using positive logic, a digit value of 1 (or a logical value of true) is represented by a more positive voltage relative to the representation of 0. Different logic families require different voltages, and variations are allowed to account for component aging and noise immunity. For example, in transistor–transistor logic (TTL) and compatible circuits, digit values 0 and 1 at the output of a device are represented by no higher than 0.4 volts and no lower than 2.6 volts, respectively; while TTL inputs are specified to recognize 0.8 volts or below as 0 and 2.2 volts or above as 1.
Transmission and processing
Bits are transmitted one at a time in serial transmission, and by a multiple number of bits in parallel transmission. A bitwise operation optionally processes bits one at a time. Data transfer rates are usually measured in decimal SI multiples of the unit bit per second (bit/s), such as kbit/s.
OK, thanks for that.
But, how does this demonstrate there is no error correction at Ethernet or USB interface?
Do you agree that UPnP does not need any error correction algorithm as underlying layers ensure a reliable transmission through the channel?
Then, from the content of the samples, and with a good clock, the original analog signal can be rebuilt.
No… I don’t agree… This is why Ravenna and AVB were created, so to provide robust error-correction throughout the network topology…
It’s called: “Quality of Service” (QoS)
OK, so you will have to explain me how we can exchange data through networks in a reliable manner.
I let you imagine how many wrong data would be sent and received everyday without error detection and correction at network level.
That would be a total nonsense. Basic principle is that communication can be noisy and consequently not reliable.
QoS on network is something more than reliable transmission of data, it includes timing aspects, maximum latency and all those things: when you are watching a TV program you need to receive correct data AT THE RIGHT TIME, and you don’t want gaps in the transmission.
The only error-correction that occurs in an asynchronous digital-audio hand-shake, is between the bus receiver of the DAC and the comparator/clock topology of the DAC architecture or elsewhere inside the DAC architecture…
All things fall apart when there is contiguous distortion of the leading and trailing edges of the signal waveform, that precipitate read-errors of the packets and the signals produced by the bus receiver, that now become the signals the DAC operates on…
I use AS with a Lyngdorf streamer (1120) with UPnP with splendid results. It works every time and sounds wonderful😀
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The question remains as to getting the best out of Audirvana… You have obviously, constructed a network architecture, that at the very least, does not suffer from gross interruptions of the signal… The term you use “sounds wonderful” is a subjective experience and is true in the context of your interpretation, which may or may not be derived from a subjective comparative assessment of a simple USB 3 → USB 2 or USB 2 → USB 2 transmission path… If this subjective assertion is derived from a juxtaposition of transmission schemes, then the interpretation: “sounds wonderful” will need further qualification.
Remember, you all listen on shitty systems. It doesn’t sound good, it’s shit.
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That might be the case, some systems been built to be very much appealing and dedicated to some people who dare to call “music” what they listen to. More realistic ones are calling those things that come out poor loudspeakers: sound (Let’s do some sound baby…).
For the others, who are interested in music, real music I mean, there are good systems. And honestly, If you can point me to a system far better than mine, I will consider buying it without a doubt.
“Real music” you’re being somewhat elitist, any examples of ‘real ‘ music you would care to share, and what you consider ‘just sound’?
If by “elitist” you mean “targeting the highest summits”, then I take that word and I will add that you can always go higher.
And you will see that in less than 10 years, most of the “music” that is produced today will be completely forgotten.
And if we loose our time and energy to applause the song of a blackbird, what will remain for the nightingale?
So, why putting much effort in building perfect audio systems, just to reproduce something made out of “Boum Boum tchak tchak”?
By elitist, I mean " the belief that some things are only for a few who have special qualities or abilities:"
That only certain music, as defined by you, deseerves to be played through good ( again, as decided by you ) systems.
And if you think that music ‘created today’ is only “Boum Boum tchak tchak”, you realyy are narrow minded as well as elitist. Your tastes and choices are yours, and yours alone, which is true for all, but to imply that you taste is superior is nonesense.
Please also link me to music worthy of my excellent system.
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