The digital cable debate and a Headphone DAC

[admin_exported]

i have read with some interest over the past couple of months about how the signal is only '1's and '2's and not prone to interference. i have read other members on here talk about 'jitter' and the like and i've also heard people say that the bog standard cable will be just as good.

i understand the interference thing, not that clear on the jitter thing, but i now know that the people who say that bog standrad cables are just as good are either deluded, tone deaf, or too scared to pay the money and find out for themselves.

I received my Kimber Kable USB to Mini-B cable the other day from Russ Andrews. It takes the signal from my laptop to my Fireye2 USB DAC which i plug my heaphones into. I honestly thought it would be better but the difference would not be amazing.

the difference is amazing. It's hard to describe how much better it is now. simply superb, open, and detailed music. for £30ish it really is a bargain. Basically, i'm no longer on the fence.

 

[The_Lhc]

simonNFL:i have read with some interest over the past couple of months about how the signal is only '1's and '2's

GENIUS!!!

 

[Anonymous]

consider it either an attempt at sarcasm or a typo due to me listening to jurassic 5 rapping about DJ numark & cut chemists 1s & 2s. doubt anyone will believe either excuse so i still look like a muppett. Ahhh Bugga

 

[idc]

How would you describe the Fireye?

 

[Anonymous]

again, brieflly, i would describe it as brilliant. there is a bit of channel bias (to the right earphone) but only at low volumes and it is not noticeable if you put the volume in the middle and use itunes as the master. I used to have an external sound card (a soundblaster X-fi or something) which did improve on the dell's own sound card. this however blows it out of the water. so much better and although it sounds stupid, it does make the music sound less like a computer and more like a proper hifi. the music.

I use Goldring NS1000 and i'm due to receive my new audio technicas tomorrow which again i am sure they will drive with ease. i do think that it would have issues driving some high end headphones tho.

I am gradually saving up for the Fubar 4 as i think that will be the nuts.

 

[AL13N]

 

[AL13N]

As far as price goes, I think it's worth it upto a point.

When you can buy (or DIY) a cable and then find another using exactly the same components costing far (far) more - just with different colour jacket and printed text (using the same ink, printed with the same printing method) - then unless different pigments deflect RFI, electrical/magnetic noise differently...

 

[davydmx]

Hey there,

from what i've read, here and elsewhere, it seems that the Kimber USB makes improvements to sound broadly similar to my Wireworld Ultraviolet cable, ie BIG improvements! Makes me chuckle how some are adamant that digital cables make no difference. Maybe they're theorizing too much about it, rather than actually trying out...

I'm content with the idea that some things in the world, even in 'my world', are beyond my understanding. But everyone's different, right?

 

[AL13N]

 

[Anonymous]

Sorry, but I simply can not believe it's due to the cable unless it was faulty. USB delivers data in packets every ms only. They have to be clocked by the USB/DAC in some way, as there is no pulse signal. A good USB/DAC determines whether it the incoming packets are of a 44.1 or 48 stream (for instance) and then clocks the samples, and makes small adjustments if needed (the buffer fills up or gets empty due to minute differences in the clock crystals). The effect of jitter in a USB connection is therefore moot (jitter in S/PDIF is an entirely different story). Also SNR for the 0's and 1's in the signal is MASSIVE - no way that the receiving end can miss that. The only reason I can think of is an analog problem due to ground loops or a noisy ground of the computer that affects the analog part of the DAC, maybe - just maybe - the cable or connections had an effect on that.

 

[Anonymous]

Pete10, i'm sure your techincal knowledge is sound but i'm afraid the ears do not lie. The giveaway cable was only a couple of weeks old and did not seem faulty. fact is people believe what they want to, all i know from first hand experience is that the difference is so noticable and better and i would happily spend the extra money.

The other thing i refuse to believe is that companies like kimber & wireworld (slightly naive on my behalf maybe) would put so much effort into R&D to effectively 'dupe' people into spending money on it's products whihch is not needed. they developed high end USB cables to improve sound, whether the cables are actually worth the money they charge is another story but the sound is improved nonetheless.

What Hifi also agree and they simply cant be wrong

Wireworld USB cable review:

What Hi-Fi 5 Stars August 2009: "The gains in low-end body and punch, mid-range spaciousness and detail, and high-end smoothness alone are significant. Compared with a giveaway lead, the sound of the Wireworld is leagues ahead"

DIV.floatAddImage { FLOAT: left }
DIV.floatAddImage P { TEXT-ALIGN: center }

 

[idc]

Simon, when you get your new headphones can you please put a review in a thread in the headphone section of the forum. You have put some very good info in this thread, which is going to be swallowed by a cable debate. On which matter.......

Pete10. What you seem to be describing is a successfully designed synchronous DAC with buffering to remove jitter, such as the Wavelength DACs. But most DACs are adaptive and rely on the senders clock as well as its own.

My understanding is that if the DAC's design can remove all jitter then the cable, or type of cable makes no difference. But, even though some claim to be a zero jitter design, such as Benchmark, there is no such thing as absolutely zero jitter. Benchmark are confident enough to say that you can use any cable with their DAC.

Then you run in problems of the audibilty of jitter and that low jitter may not correlate with better sound quality. So you could have a gigital cable that introduces jitter, but makes the end sound better!

 

[Anonymous]

Simon, I do not mind at all that you disagree. In fact, I disagree with the majority of the people on this earth, on topics sometimes almost as important as cables. I'm just stating the points that - as far as I know - could and could not result in HUGE differences like the ones you describe, or what the whathifi review claims.

Idc - I indeed also read about the different types of DACs. From the schematic of the TI/BurrBrown design of USB-DAC and the corresponding explanations I concluded that the problems of isochronous USB are minimal now. That includes FIFO buffering, reclocking using an internal crystal (that may or may not have a lot of jitter) and some adjustments only if the clocks get out of sync, "spAct". I agree however that a synchronous system seems to be a more elegant solution. Anyway, even if this is not the case it is questionable if a 1 meter cable affects jitter that much and creates these huge differences. A USB DAC of course also has analog amplification to create the analog output signal. It is feasible that this is affected by the connection to a laptop and even the cable.

I called MF once to ask about the quality of the USB input in the VDAC and the X-CAN. To my surprise they said that in particular for USB input the VDAC was superior, and more similar to what they use in their more expensive gear. So apparently there are still differences between USB-DACs.

 

[idc]

Pete10 you have seriously good knowledge there, what is your background?

I agree with you about the effect of a short run of cable. How likely is it to affect jitter to such an extent that it can affect the overall sound? Remy Fouree in Stereophile states that any two cables with the same impedance, no matter the cost, will have the same effect on jitter in the same setup. That is about all I can find regarding impedance.

I too have spoken to MF about the USB DACs and again I was told that the one in my X-CANV8P is a 'starter' and the V-DAC has one that competes with very high end DACs. But it is the same USB chip and DAC in the X-CANV8P, the V-DAC and the X-DACV8. I can only assume that the rest of the hardware is different, particularly in the analogue domain and so there lies the difference.

EDIT - I checked back and for all three it is a USB receiver chip: Burr-Brown PCM2706. That info comes from modders opening up their DACs to see what is inside.

 

[Anonymous]

Background in science. not electronics, and just curious. I do not like unlikely explanations, so I try to understand the background.

Strange indeed if the chips are the same.