Higher End DACs

What works, what’s cost effective, and what is today’s best possible sound quality for lossless streaming spans a huge spectrum of hardware complexity, software optimizations, weight and cost. The zero’s and ones are exactly the same be it a system built around Raspberry Pie, a SOC, a i7 or dual scalable Xeon CPU’s with 20 cores.

What is different is the RF emissions collection, and how it effects the sound quality. Here are my takeaways, observed over the last 5 years, and independently verified by intense DIY professionals like Romaz.

It has long been observed that lower software execution latency helps improve SQ, and we find it is still very much the case today. Lower latency shortens the CPU active time, and CPU associated RF emissions. What high powered CPU’s bring to the table are faster thread execution times, less CPU busy time, and that noticeably increases SQ to levels that slower and less powerful CPU’s cannot match.

RF emissions in the Kilo to Gigahertz  frequency bands which are emitted by the various clocks in digital gear can be attenuated by good shielding and grounding but what still gets through and then infiltrates in to the analog EM signal amplification environment results in an easy to identify audible signature. When carefully managed and shaped, these RF emissions can be SQ enhancing.

Digital equipment is as sensitive to mechanical vibrations as analog equipment. All crystal clock oscillators are vibration sensitive to an order of magnitude greater than their steady state frequency drift. Clock oscillators’ output signal voltages are also quite sensitive to power supply fluctuations. Overbuilt power supplies make their sonic presence heard in digital equipment.

Playing Streamed files does not require much CPU power, but the quantity of IP traffic going up and down comes with its SQ unhelpful sonic signature and the reason why the sonics of streaming are behind well implemented PCIe storage and RAM playback.

So while the size, complexity and cost of a high powered music server might seem to be over the top, the level of sonics one of these servers can deliver is not snake oil                                                                                                                                                                                                                                                                                                        

To get to the specifics of the Extreme and why its very good at streaming, is the the optical SFP port which allows a somewhat noise cleaner LAN feed than copper.

With Qobuz the sonics are extremely enjoyable !

What’s this a sales pitch for a over priced computer to stream Qobuz? If you really want to keep all that noise down have the server in a different room and connect through ethernet problem solved. CPU latency isn’t a problem streaming over the internet neither is execution time they use ARM chips for the most part not x86. 

I am trying my best not to make my posts a sales pitch, but to provide insights about we have observed and what we think is going on.

re your first point, the two modern choices of getting data to the DAC are a) Renderer in the DAC as data entry channel and b ) via USB to a USB receiver 

of the top line DAC’s we have seen, and tried out and reports we have received, USB has a nose ahead of IP in the SQ race.

A major high end DAC manufacturer actually recommends removing their Renderer module for an audible sonic uptick

it is a trade off between noise coming from LAN activities against noise coming from the USB receiver

To your second point, we have found that latency maters both for OS activities in the CPU and for interestingly for the LAN network and the internet backbone behind it.

For a long long time, we could not understand why real time streaming sounded noticeably better in the Netherlands than in the US.  The SQ delta between onboard storage and streaming in the Netherlands was quite small, whereas the gap at some customer sites in the US was huge.  Well guess what, a lower the latency of the network connection to the streaming services server resulted in noticeably better sound.  In the Netherlands there has been for quite a while a glass backbone to the IP infrastructure with very low latency and that was the SQ edge In Holland

we can even hear the SQ delta between streaming and onboard storage get smaller at night as the latency of the connection reduces because of lower traffic.

This being said you can still get very good and enjoyable sound quality from streaming even when the difference is quite noticeable.  We don’t come across many installations where the network latency is so high that it results in a sound we don’t want to listen to and can’t enjoy

The zero and ones are exactly the same, but the RF sauce that comes with it Is latency influenced and sounds different

I hope the above is helpful in describing the RF landscape that effects Audiophile sound reproduction

The RF "sauce" is not latency influenced. How much RF is bandwidth influenced. If you are making the router/switch work hard (latency has little impact on that), then the RF signature goes up.