USB cables that work, or don't, with DS

Just had a USB issue and thought I’d share…

My system (Mac Mini/PWD/iTunes/BitPerfect) suddenly stopped producing sound and after some time trying various fixes I swapped USB cables and bam, problem solved. Generic $5 USB that I dug out of my “bag o’ cables” replaced the Audioquest Forest (both 1 meter).

Sounds great BTW…

I should add that PSA support was extremely helpful (and patient) assisting me with this issue

I faced very similar problem with DirectStream dac too. Not sure whether it is DirecStream Dac’s problem or problem with the Audioquest cable. The audioquest cable runs great with MusicalFidelity VLink which converts Asynchronous USB to SPDIF.

Looks like PS Audio DACs don’t like those high end cables for some reason.

Regards,

Sourav

Sourav Mazumder said Looks like PS Audio DACs don't like those high end cables for some reason.
Or your statement might be re-phrased as 'Looks like the PS Audio DAC don't like high end cables that don't follow the USB spec'

Yeah, here’s the thing…The cable was working fine for about 4 weeks so I find it odd that it would suddenly stop working. I mean, it’s a cable, it either works or it doesn’t right?

I need to do some more testing but I am not 100% convinced that it’s the cable’s fault…

PSAuadiofan said I mean, it's a cable, it either works or it doesn't right?
Nope - for example if a USB cable is too long, say near 15' or made with the wrong impedance then the amount of time it takes for the signal to get thru will be close to the maximum amount of time allowed. At that point small changes in temperature either in the cable or (more likely) in the electronics on either end of the cable can cause the signal to be too late every once in a while and the system (which also contains transmitters and receivers in the hubs, PC and DAC, along with the cables) becomes flaky. Another way an out of spec cable can be unreliable is that if the VBUS (the so, called, 5V line) isn't hooked up or has the wrong resistance or capacitance, then whether the system works depends on the particular hubs, transmitters, receivers, and software in the PC, DAC, etc. A software update on the computer or the DAC or simply plugging or unplugging some other USB device can cause a cable (or more correctly a USB connection) to stop (or start) working...

The simplest test is if a certified USB cable (say the Belkin Gold) works reliably then the problem is almost certainly in the other cable.

Huh. Thanks Ted, I learned something there…

Then it’s disappointing (and frankly mind boggling) that higher end cable manufacturers would not adhere to every spec, if they exist, when building a cable.

I tried a battery on my usb cable last night and had no issues. Maybe it won’t last. However I was pleasantly surprised at the improvement. A little more musicality and definition, especially around the bass lines which are easier to follow and more tuneful.

I’ll keep listening this way. I’m waiting for a Regen too. What a hobby!

I think you will find that non-conformance with spec is pretty often the rule rather than an exception. The more exotic the less compliant, IMO. Quite frankly the knowledge and craftmanship are quite disapointing and this is only possible because customers trust all the marketing bs (and I admit I am one of those believers 65_gif )

I’ve emailed Audioquest asking about USB compliance in their Forest USB cable. I’m interested to hear what they come back with…

PSAuadiofan said Huh. Thanks Ted, I learned something there...

Then it’s disappointing (and frankly mind boggling) that higher end cable manufacturers would not adhere to every spec, if they exist, when building a cable.

Playing the devil's advocate:

The classic way to get an competitive or performance advantage is to figure out some shortcut that no-one else has the insight or guts to try. Most of hi end audio are people/companies “cheating” one way or another (including me.) A lot of the problems in audio are quite hard and one needs to use experience and/or judgement to figure out which constraints matter the most and, sometimes, which incompatible constraints to relax or punt on.

Many audio cables are built by people that think that, say, the dielectric or the waveform shape or the propagation time, …, matters more than most other people think. If they concentrate on a few of them they may be forced by physics to compromise somewhere else.

In the case of the DS I believe that jitter and lower slope filters matter more than absolute noise level. The DS (and other single bit DSD DACs) put out more noise that most people consider reasonable for a DAC: I believe that the resultant clarity and emotional involvement in the music are worth the crap we have to take for having a higher noise level - other manufacturers have different experience / opinions.

In the case of audiophile USB cables most early customers didn’t have any USB hubs and perhaps didn’t even have any other USB devices other than their DAC, they may even only been using USB 1.0 or 1.1. You can get away with a lot if you don’t have to worry about other devices coming and going, or you don’t have to worry about a chain of seven hubs, etc. As time goes along and there are more and more types of USB trying to be downward compatible with earlier versions it becomes more and more important to play with others and follow the specs very carefully. That’s what the specs are for, in almost all circumstances if everyone plays according to the rules, you can use any cable with any device on any host…

I get it Ted, but I see two different issues in your examples. One is tweaking where there really is no 'spec" per say, the other is tweaking and ignoring/not adhering to the spec.

Which begs the question; if the cable doesn’t meet USB spec can it (or should it) be referred to as a USB cable?

Indeed non certified “USB” cables shouldn’t be advertised as USB cables and would probably get in trouble if they used the USB logo’s or claimed to be USB certified.

A lot of audiophile power cords won’t meet UL, for that matter many audiophile amps, peramps, etc. don’t. Most powered audiophile gear violates many specs about power factors or power supply efficiency…

Some legitimate equipment doesn’t work on most balanced power systems…

RCA connections can’t be 75 ohms…

Anyway I agree that calling a cable a USB cable when it doesn’t meet every spec for, say USB 2.0 or USB 3.0… is a bad idea and annoys a lot of us.

Audioquest got back to me already (that was quick!) via email. However, they ignored my question regarding the USB 2.0 spec for their Forest cable and asked me to return the cable for a replacement. Fair enough, but I don’t see how this will help me if the replacement cable is exactly the same as the “bad” one I’m sending back…

I’ll play along and give the new cable a try. Maybe they made changes for the better in the brief time between now and when I bought the first cable.

Ted, yes “annoying” is the appropriate adjective here…

Just to relate my experience with the DirectStream fed from a laptop: generic USB 2.0 cable sounded much better after adding an AQ Jitterbug.

Then I replaced the above with an 0.7m iFi Gemini cable. I wasn’t expecting to hear much difference, but it was immediate and obvious: smoother, more detailed sound. The iFi Gemini is a two cable system, with the data and voltage/ground running separately but adhering to the USB spec for impedance, and carries 3 ferrite cores. Luckily there are two USB slots next to each other on my laptop so it worked just fine.

Knowing how much the Jitterbug improved the generic cable, I added it to one of the iFi Gemini connectors. The sound was worse, giving it an unpleasant edge or glare. I switched it to the other connector, and it didn’t sound any better. This didn’t make any sense after all the positive reviews of the Jitterbug. Still, I heard what I heard and removed the Jitterbug. The sound immediately improved.

I plan to reintroduce the Jitterbug at some point to test my findings. But the short of it is that the iFi Gemini is a winner.

I’m going to harp on two things here. Firstly, get a Belkin Gold USB cable. It will set you back less than the cost of a CD and is a good reference to have around. I don’t mean “absolute” reference in the audiophile sense, just a reference point. It sounds good and is “to spec” for USB. Is it the best? That is not for me to say… Secondly, I have encountered Nordost USB cables several times and my advice is to try before you buy. I love their power cables but not their USB. They need to take these back to the drawing board, IMHO.

The 18" Monoprice “gold” USB cable (less than $4 via Amazon) I have in place of the Audioquest is working great so far, no issues (apparently this cable is “USB compliant” for whatever it’s worth…). So no need for the Belkin at this point but I will keep it in mind…

BTW, I did receive the replacement Forest cable from Audioquest, still in the box, haven’t gotten around to switching it out yet. Pretty happy with Audioquest’s customer service.

I have found Monoprice to consistently provide excellent value. Nothing exotic, but solid inexpensive cables.

PSAuadiofan said apparently this cable is "USB compliant" for whatever it's worth...)
....and this is worth a lot, IMO

I have used monoprice and Amazon mediabridge (hdmi, subwoofer, digital coax) for my home theater for years and never had any complains on the sound quality but I could never understand why I am not happy with the results of my expensive cables for 2-channel audio yell

Yes, I was surprised at how much I dislike the Nordost USB, and that during several comparisons. Others have commented that they have even had trouble with exotic USBs even working at all with their equipment.