Hello folk,
During my tests with Audirvana, I observed that audio quality via the USB of a laptop was far inferior to a UPnP connection.
As UPnP is not really reliable, I would like to study other solutions that could be implemented.
Thank you for your feedback!
While I use UPnP and it has proved reliable for me, I also have an optical USB cable, powered at the DAC end by a Teddy Pardo “mini-Teddy” LPS.
However - the manufacturer has apparently stopped selling the optical USB cable. It was the only true optical USB cable I was aware of - the others all have thin copper wires for electrical contact. So that’s no longer an available solution, unfortunately.
I’m quite wary of USB reclocking. The great thing about asynchronous USB input is that the clock is right where it should be for best performance, in the DAC. It would be very difficult for an external clock to meet or exceed that time accuracy from a distance away using a phase locked loop (PLL).
My opinion, for what it’s worth.
USB 3 removes request signaling from the data path which reduces latencies…
I use a 4" (four-inch) USB 2.0 “cable” which reduces latencies (A Printed Circuit Board adapter no longer available from Up-Tone Audio) from my iFi Audio iGalvanic (no longer available… iPurifier 3 is the option now) to my DAC. iGalvanic is re-clocking and isolating the USB 3.0 signal delivered via a Wire World USB 3.0 cable from my USB 3.1 controller housed in a Thunderbolt 3 PCIe expansion chassis with a Elfidelity Rainbow Sugar II PCIe bus-power filter card…
So these sorts of assertions are purely subjective in nature as they are contextually bound to one’s amalgamation of system components and the adroitness of the transmission path design architecture and the system implementation(s) in aggregate.
Note: My entire playback system resides on it’s own ‘power/ground/earthing island’ with extensive multi layered filtering and conditioning, in synergy with an ADD-Powr EAU2 harmonic resonator on the mains power feed. 
On my side I use UPnP with Audirvana Windows or Linux and it is now reliable. In the past there were stabilities issues.
The work of Audirvana on UPnP has paid.
On my side I use Diretta behind UPnP.
With some DAC with not really good USB interface you can use things like Holo Red to choose the better input for your DAC.
There are also USB interface (without streamer)
You can also use good USB output ( USB Card FEMTO - JCAT .
or Ifi product that can improove sound like @Agoldnear said.
It depends on how much money you want to spend and the connection types your DAC supports. But Mutec, Singxer and Denafrips create digital-to-digital interfaces which often clean up the signal before sending it out again to the DAC. Good ones are not cheap.
USB 3 protocol is the the fundamental platform for improving the quality/integrity of the digital-audio signals in transmission … If the DAC does not require power from the USB interface, it can be removed from the transmission line with something like an iFi-Audio iDefender+ isolator.
One other idea, again for whatever it is worth:
If you don’t want to give up on UPnP but would like to make it as reliable as possible: You could try using UPnP over Ethernet, which is usually more reliable than WiFi. I use optical Ethernet, which allows electrically isolating the UPnP endpoint and DAC. You can then power the endpoint and DAC with good LPSs.
A further step toward reliability that is not too expensive is powering modem, router, and switch from an uninterruptible power supply (UPS) with automatic voltage regulation (AVR). My internet connection had occasionally been dropping; since I installed the UPS it has not dropped once. Perhaps the modem or router was sensitive to voltage fluctuations.
Ultimately… overall reliability and playback sound-quality are intrinsically bound by distance from the encoded digital-audio bits lifted from the storage medium and the DAC and whether or not this is streaming digital-audio from third-party vendors and the number of technical hops the signal makes through hardware topologies, whether this is wired or optical in nature… More components in the signal path is not a good strategy… I don’t know of any reference playback system that does not adhere to this axiom… Simple is better.
The shorter the distance the digital-audio signal must travel, the better chance this signal will arrive at the DAC as the best possible packet transmission of the bits stored on the storage medium or those packets which have been transmitted through the World Wide Web to your system.
Using a packet management protocol like Diretta or Bulk PET will certainly reduce noise influences on the transmission scheme, however these protocols will be even more effective when employed on transmission lines/networks that are short and simple in nature… The drawback with either of these protocols is the necessity for symbiotic DAC hardware/firmware support, so although they present a methodology for mitigation of noise related influences on the digital-audio packet integrity at the interpolation level, they are not ubiquitously adopted by all DAC manufacturers… TEAC/ESOTERIC support Bulk PET protocol in their devices… These protocols add another layer of CPU overhead which also may present some problems on some playback system platform configurations.
https://itf.co.jp/prod/audio_solution/bulk-pet/bulk-pet-en
Use ethernet link for UPnP is indeed imperative.
Diretta is also a very good idea, with a streamer RPI based you can use it as
Diretta target and Asio Diretta Driver on Windows PC… It’s a real gap.
Good power supply is also important…
But the fist thing is perhaps to understand your stability issues with UPnP : crash depends from connection ? from frequencies ? what is your system UPnP ? Is it implemented by your streamer ? By open source solution ?
Outside of misalignment of UPnP protocol implementations, In a perfect world, an Ethernet transmission-line scheme will deliver the digital-audio bit-packet information without noise related influences on the signals the DAC ultimately reproduces… Unfortunately, these implementations are not standardized and network architectures vary as widely as there are Audirvana user playback system scenarios.
USB provides the benchmark standard for reliable transmission of digital-audio bit-packet information and is far simpler to address the gremlins and implement mitigations that will have contextually tangible influences on the presentation of the encoded bit-signal in the final audition, on any given amalgamation of playback system components… Many modern DACs are now being designed so to manage the gross influences on the encoded digital-audio bit-signal imbued in the mastered bits as lifted from the storage medium.
Hello all,
thank you for your very interesting messages.
I think USB Card FEMTO or IFI AUDIO IPURIFIER are good candidates.
What do you think about AUDIO-GD DI-24HE Digital Interface:
At the same time, I’m also trying to solve my UPnP problems. I have several posts open on this forum. But it is very difficult to make progress on the tickets because the problems have multiple stakeholders: Audirvana, the stremer and me ;-).
At the same price Holo Red can do DDC or streamer, and as streamer there are valuable UPnP implémentation with system like GentooPlayer or Audiolinux, or you can use it as Diretta Target with Asio Driver on your PC, I tested all of them with Audirvana and work fine.