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Well, the jitter spectrum of the QB-9 Twenty looks good at least. I really should get my QB-9 DSD upgraded.
Digital sources: Roon Nucleus+ music server; MBL N31 CD player/DAC; Ayre Acoustics QB-9 Twenty D/A processor.
Power amplifiers: Parasound Halo JC 1+ monoblocks.
Loudspeakers: GoldenEar BRX, PSB Synchrony T600.
Headphones: Audeze LCD-X, Sennheiser HD-650, AudioQuest NightHawk.
Cables: Digital: AudioQuest Vodka (Ethernet), AudioQuest OptiLink 5 (TosLink). Interconnect: AudioQuest Wild Blue (balanced) & Fire (single-ended). Speaker: AudioQuest Robin Hood. Headphone: Nordost Heimdall with Audeze LCD-X. AC: AudioQuest Dragon Source & High Current, manufacturers' own.
Accessories: Sanus 29" loudspeaker stands; Target TT-5 equipment racks; Ayre Acoustics Myrtle Blocks; ASC Tube Traps, RPG Abffusor panels; AudioQuest Niagara 5000 Low-Z Power/Noise-Dissipation System (amplifiers) and AudioQuest Niagara 1000 Low-Z Power/Noise-Dissipation System (source components). AC power comes from two dedicated 20A circuits, each just 6' from breaker box.
Room: 20' (left side), 25' (right side) × 16' × 8'.John Atkinson
Well, the jitter spectrum of the QB-9 Twenty looks good at least. I really should get my QB-9 DSD upgraded.
Good catch!
That's probably the review of the QB-9 Twenty in its entirety. After all, the Twenty is an upgrade to a no longer manufactured product.
And, yeah, you should get the upgrade. At the risk of sounding like a shill for Ayre, the upgrade is really worth the asking price, and probably a lot more. (Which I paid in full - if I'm a shill, I'm also a very bad negotiator.)
I just upgraded the USB board in my QX-5 Twenty and WOW, I was not expecting this kind of improvement. Definitely a worthwhile upgrade. I guess we're both shills for Ayre. :-)
I can see why.
Compare Figure 16 to the comparable plot in the Stereophile review for the original QX-5 Twenty.
Of course, many, many people will tell you that this sort of thing is inaudible and that you are crazy. But, crazy people can be happy, too.
Hi
When one crazy enough to burn his/her easy money to be happy, why not ?
Life is short so make the best use of it.
Jacl L
Somewhat OT:
This seems as good a place to ask this as any.
This particular digital solution seems to perform not quite as well as some other products with regard to jitter sidebands. Is this audible? By how much? Why?
Now... Head to the bottom of this very web page and click on the button that says "hi-finews". That'll take you to a website for the magazine of the same name.
Look at a turntable review. Any turntable review.
In the Lab Report, there is a plot of what is labeled Wow and flutter. This is a spectral display of a single tone from a vinyl disc played back through the turntable under review.
Isn't that pretty much the same concept as the jitter test, at least with regard to the central tone of the J-test at 11 KHz?
So, how is one to interpret all of this? One is obviously far different than the other.
It's not obvious from either plot and associated labelling what the measurement parameters are for the spectrum analyzer. The resolution bandwidth, the video filtering, the averaging type and number of samples, the detector type, and so on are not shown for either. (To be fair, this might be explained in an article somewhere that I failed to find - my bad.) Variations there would explain a lot. But, maybe there's much more to it.
I find this all confusing. Perhaps I am the only one who does, though.
Perhaps I am overthinking all of this, too. Wouldn't be the first time.
I don't think there's much confusion here. Jitter was never all that audible as an issue. No need for audiophiles to fear this "boogeyman" in general. I posted a demo for folks to listen to years ago - just Google "Archimago Jitter Demo".
Yeah, the J-Test for a device like this is not good for modern 2021 digital especially for the 24-bit ethernet input. I still don't think it's audible in real music anyways, it's more of a reflection of the engineering that the time-domain wasn't better despite the claims of using femtoclock parts and the ESS ES9038Q2M DAC chip!
No surprise as well that turntables are comparatively inaccurate vs. digital (Google "Archimago vinyl LP fidelity" for a discussion). It's very obvious if one listens to a pure tone like 3150Hz as per HiFi News. Time-domain is poor with LP playback not just because of turntable rpm variations but also the imperfections of the vinyl itself. Again, with music we don't notice these issues as much.
Nice article. Thanks for testing storage drives (i.e. usb thumb drive, portable HDD, etc) on this device Some of us have amassed significant size CD quality or better on storage drives. From the late 90’s and before streaming had the quality we see tday. Streaming Qobuz and Tidal are impressive but some of us aren’t quite ready to pay for yet another streaming subscription. Articles like yours (and the use of Roon) help prepare us for if that plunge ever comes.
Hi
If only HD music videos are needed (what else??), I would not bother to spend my nerves & hard-earned cash on those bells & whistles loaded 'hi-tech' streamers.
Yes, YouTube provides 24/7 tons HD & 4KUHD music shows, streamable FREE by any WiFi HD & 4KUDH blue-ray players. Let's lead a simple life & enjoy really
eye-widening & ear-thrilling HD/4KUHD music shows on our 4KUHD TVs streamed free from YouRTube. Who needs to sweat fighting with those complex 'hi-teck' remotes ???
This is exactly what yours truly have been doing since a couple years back. I simply feed the digital PCM audio signals from the coaxial O/P jack of the HD Blu-ray player to my 24bit/192KHz DAC which in turn hooked up to the linestage I/P of my design/built tube phono-preamp with its PASSIVE bypass switched on. So the HD audio signals from the DAC electrically feeds direct to the power amp !
Please note any DACs deliver adequate output voltage to drive directly any power amps to their rated full output power. Or simply feed the DAC L/R analogue audio signals direct into the power amp if it comes with built-in volume controls. The sonic is sooo rewarding..
With such DIRECT signal feed to the power amp, the HD sonic quality of so many those HD/4KUHD music shows from YouTube becomes surprisingly sooo good to make my skeptical vinyl-addicted ears up-pointing !! No kidding.
Life is short so let's make it simple.
Listening is believing
Jack L
The one year warranty from a new company is a disappointment. At a minimum it should be two years. The NAD M10 and Cambridge Audio EVO 150 are covered for three years. I've had far too many expensive electronics fail within three years of ownership. HP replaced a 4K monitor that stopped working unexpectedly after two years (covered for 3) while I was out $2k when my Noble Audio IEMs failed shortly exceeding their warranty period.