HiFi Rose RS250 audio & video streaming D/A preamplifier Associated Equipment

Sidebar 2: Associated Equipment

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

COMPANY INFO
Citech Co., Ltd.
US distributor: MoFi Distribution
1811 W. Bryn Mawr Ave.
Chicago, IL 60660
(312) 841-4087
ARTICLE CONTENTS

COMMENTS
Axiom05's picture

Well, the jitter spectrum of the QB-9 Twenty looks good at least. I really should get my QB-9 DSD upgraded.

CG's picture

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.)

Axiom05's picture

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. :-)

CG's picture

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.

CG's picture

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.

Archimago's picture

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.

BluesDog's picture

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.

X