QED Reference USB A to Micro B Ultra Low Jitter
Nov 23, 2015 at 7:17 PM Thread Starter Post #1 of 5

imattersuk

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In recent years audiophile USB cables have given rise to much debate and at times even outright aggression on various forums....... There are many who feel that the improvements apparently heard by using an upgraded USB cable are purely imaginary. The debate regarding 1’s and 0’s rages on and for many years it wasn’t something I felt inclined to explore in any detail. As the owner of a pc building business in the late 90’s I just went along with the logical view that data is data.

That was until I set up my first streaming system comprising Sonos into a Rega DAC about 5 years ago. I had already experimented with various speaker cables and interconnects and I recall concluding that after much testing I settled on a Rega Couple, totally convinced that it was not necessarily “better” but matched my system “better” and therefore sounded “better” to my ears than anything else I had tried. I remember there being a huge difference in characteristics between the Rega Couple and The Chord Company Cobra. I also recall some custom made silver cables that sounded harsh and totally unacceptable. Once again I found myself falling into the trap of listening to the equipment rather than the music, something I vowed to stop doing back in the 1980’s !!!

 
It was during this pursuit of perfection that I stumbled across the subject of jitter. There was something bugging me about the overall quality of the Sonos based system, a slight harshness, artificial, hard to describe characteristic, I could still remember the Pink Triangle based system I had in the 80’s and was striving to bridge the gap between analogue and digital.
I saw a secondhand Theta Digital Timebase Linque Conditioner advertised for £50, the answer to my prayers ?? Well not quite because the damn thing used to cut out and hum like mad when connected to the Sonos, a real piece of crap I thought but…..when it wasn’t humming it sounded fantastic. To try and nail down the issue I hooked it up to my LG Blu-Ray player and slapped a CD on, no hum, worked perfectly and I was absolutely gob smacked at the improvement but never did get the damn thing working with the Sonos. Well that was five years ago and that system is long gone and the extent of my current equipment comprises Oppo PM-3, Chord Mojo, Macbook Pro (occasionally LG G4 phone).
 
The extent of my recent tinkering is converting my Apple Lossless files to FLAC via Max, yes I do hear a difference, to me the FLAC’s are more detailed, weightier with more clarity, like a veil has been lifted, I’m not good at using audiophile speak, in fact a lot of it sounds like absolute tosh to me but I do know when I hear something in more detail with greater clarity, I can recognise space around instruments, differences in soundstage blah blah but beyond that is a place I’m not going to.
 
So having recently upgraded from the Oppo HA-2 to the Chord Mojo I finally started to engage in debate on Head-Fi, 99% of the time on the monster official Mojo thread. Initially I was posting about the lack of cables supplied with the Mojo. I was highly critical of the perceived tightness of Chord not to supply a basic set of cables, something that was supplied with the HA-2.

I like to think I’m fairly open minded and fair and this was not a subject I thought I would change my opinion on easily. As the thread progressed there was much debate about cables, many custom made short varieties of optical, cheap and cheerful OTG for phone users but not much about USB A to micro B, probably because that is the one cable that Chord did supply.

The supplied cable is very short and I found it frustrating so I grabbed one of my cheap charger cables lying around and started to use that with the Macbook, that’s when I had a slight inkling that there may be a difference between USB cables. Something was bugging me, the sound was good, even great but something wasn’t sitting 100% right so I did a little bit of testing between the short supplied cable and my longer, ultra thin charger cable and there was a difference but it was slight, very slight.
 
Out of the blue came an offer from another forum user to test and review a high quality cable designed to reduce jitter, here we go again I thought, had a little chuckle to myself and thought ok why not, despite having vowed for the 500th odd time never to start listening to the equipment again !!!
 
The cable in question is the QED Reference USB A –micro B.
 
http://www.qed.co.uk/hdmi-and-digital/digital-data/reference-usb-a-b-micro.htm
 
First impressions, nice box, nice looking cable, the cynic in me thinking well they have to make the box look nice if they are going to charge £59.99 for a USB cable. On unpacking the first thing that hits you is the thickness of this thing, it’s like a small grass snake but far less flexible, more of that later.
 

 
 
 
Build quality is very high, it really is a quality product, now onto the testing.....
 
As tempting as it was to just hook it up and give it a try I resisted as I wanted to do this as impartially as I could. You see although i’ve never minded spending out on a quality mid range cable in the past I expect value for money, nothing winds me up more than overpriced, overhyped junk, not just with my own wallet in mind, I hate to see people ripped off.
 
The testing was all done with the PM3/Mojo/Macbook/FLAC via Vox  combination and all blind. It was then repeated with my partner doing the listening and her opinion mirrored mine despite suffering from serious tinnitus and having zero interest in hi-fi or anything audio / gadget related, in fact she’s quite happy with her £15 pair of Sony headphones and iTunes downloads.
 
So how does it sound ? Is it better than the stock cable ? Hell yes and by a large margin. The easiest way of describing it is that it’s similar to the improvement I heard when comparing the HA-2 to the Mojo, more detail & clarity, a lot of the tracks seem to come to life, now that confused me because the Mojo is so damned good out of the box with the stock cable, I was already hearing things I didn’t know were there, a cliché often used I know but it’s true !!. You aren’t going to get lot’s of hi-fi speak and terms out of me, I’m not going to go overboard and try and describe the sound in huge detail but the high end is where I feel the biggest improvement is, more sparkle without introducing brightness.

I would suggest you order one online and try it for yourself. I’m not a great lover of distance selling regulations in the UK as I think it’s a system that’s often abused by UK consumers who use it to audition gear but I’m confident you will hear an improvement and end up keeping it.

 
It’s not all great news though, there is one downside. The cable I have is 0.3M long, perfect for the Mojo/Macbook, I can sit with them on my lap, however I have a very wide armchair and boy do I need that space, this thing is very stiff, in some respects worryingly stiff in relation to putting strain on the USB ports of both devices. Maybe I’m being a bit picky here but you will see what I mean if you try one. On a desk with adequate room it’s not a problem but for casual listening on a laptop actually on your lap, it’s not very practical.
 
If you want more info about jitter and what it is here’s a link that I found useful a few years ago.
http://www.positive-feedback.com/Issue43/jitter.htm
 
This review has been produced with the genuine intention of giving a 100% honest opinion. I don’t do BS, I don’t believe in fairies or werewolves but I do know what I hear and to my ears it’s shown a big improvement switching to this cable.
The last thing I would like to suggest is that if you do a blind test yourself do not do it by having someone swap the cables with you present in the room. The sheer thickness of it means you would probably hear the difference in how they would be connecting it up. I recognised this as a potential problem with the testing before I started, maybe a bit OTT but I wanted to make sure the test was accurate. I also used the same USB port on the Macbook so did not have two cables hanging out of it just in case there was a difference between the ports. I have also tested it versus the optical out on the Macbook and USB wins hands down with the QED and the stock USB cable just edges out the optical too, guess what I’ll be trying next, yes a different optical cable !!!!!
 
Nov 24, 2015 at 3:12 AM Post #2 of 5
Very interesting write up. I too have a Sonos/Rega DAC setup connected to my HiFi. Less used now that I'm also into Headphones/IEMs for more and more listening. For that combo I use QED digital co-ax. Recently tried a demo Hugo TT in place of the Rega and was amazed at the difference. Same too with a Hugo, but what was noticeable was the difference between optical and coax with the Sonos, optical seemed softer.

Think you took big steps for a fair test, getting cables swopped blindly, rarely have patience for that, nor with exact level matching which I accept is relevant. I listen to gear for an hour and ask myself do I enjoy the music im hearing. In this way I'm not sure small cable differences would be pronounced.

The only concern I have with your findings is the headphone used! I found at a UK Head-Fi meet, the Oppo PM3 one of the most boring, laid back phones I'd ever heard. Had some lovely qualities but would kill any uptempo music for me with its warm and cosy softness. Any cable that could liven it up, in a good or bad way would help my listening! I know we all hear differently, so that's not a critism and just a personal preference, but just throws up that what a cable does for one system or person, may have rather different consequences in another.

Thanks for sharing your thoughts in a measured way, far too often we read crap that it doesn't matter what you hear, 0s and 1s rule. I wonder if these people really enjoy music! I like to keep an open mind.
 
Nov 24, 2015 at 7:01 PM Post #3 of 5
I don't think it is jitter that is causing the difference you're hearing, more likely the better isolation from noise. Higher jitter, assuming the receiving device is affected by it, will more likely result in a smoother sound with less detail. That requires it to be extremely high. Take this quote from Rob Watts, similar to what he has said before on here:
 
Quote: (http://www.the-ear.net/how-to/rob-watts-chord-mojo-tech)
  I am getting rather different sound from coax and USB inputs with the latter sounding better, what’s the reason for this?

It’s complicated and depends upon a number of factors - principally the amount of RF noise injected into the Mojo, and the amount of correlated noise that gets in. It will depend upon the source device as to which sounds best. My preference is optical, as this has the smoothest sound quality and best depth, as it does not suffer from both of the aforementioned problems.

 
In my experience with one of the lowest jitter sources available, the Audiophilleo 1, it was far better after the Pure Power was added, and that was purely a device to remove power supply noise entering the circuits which, to my ears, caused the harshness you describe. 
 
Mar 31, 2016 at 3:21 PM Post #5 of 5
I'm now using this cable based on the review above (thanks!), for use with MacBook & Chord Mojo. It does make a noticeable difference to sound but I have one issue with it. It's so thick & the connector is so bulky that the micro usb plug often gets disturbed if I move so the mojo then loses it's connection with the Macbook. 
 

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