USB Cable Comparison Audience / Cardas / Purist / Stealth / Wireworld


I've been meaning to share my findings and impressions from a recent six cable comparison of USB cables.

What follows is a 'work in progress draft' that I will be finalizing and posting on a blogging site.

Getting this posted is a way of lighting a fire under myself so I get the write-up finalized. And to keep my promise to share my findings with a number of Audiogoners.

What is posted is the first phase of the 'shoot-out' involving four cables.

Please note:

- This is not finalized and I will be making edits, and adding information, etc.

- This is the first phase of the comparison.

- The second phase will be posted soon.
david_ten

The following cables were made available through The Cable Company's Cable Lending Program:


1. Audience Au24 SE Plus USB 1M ($895)

2. Cardas Audio High Speed Clear USB 1M ($400)

3. Purist Audio Design Ultimate USB 1.5M ($900)

4. Purist Audio Design 30th Anniversary 1.5M ($1,500)

5. Stealth Audio USB 1.5M ($850)

6. Wireworld Platinum Starlight 7 USB 2.0 1M ($700)


Actual length of each provided cable is listed in meters.

All prices are List in US$ for 1 meter lengths.

I personally selected four of the cables with the following exceptions: XX (for privacy) recommended the Purist 30th Anniversary. Peter Hansen of The Cable Co. recommended the Stealth.

The comparison was conducted in two phases. The first phase between Cables 1, 2, 3, and 6. The second phase between Cables 4, 5, and 6.

The first phase took place in October 2017 and the second phase took place in Oct - Nov 2017 with both phases taking about two weeks each.

General system information:


- Windows 10 Tidal / Roon - source / software.

- Small Green Computer sonicTransporter AP - Roon Core.

- Sonore ultraRendu with Uptone UltraCap LPS-1 [for Phase 1 cables] - Roon Renderer

- Sonore Signature Rendu SE [for Phase 2 cables] - Roon Renderer.


Schiit Yggdrasil Gen 3 USB > Pass Labs XP-20 > Pass Labs XA-30.8 > Tekton Design Double Impacts (4Ohm, upgrade package)


Each cable (considered broken-in per The Cable Co) was run with signal for about two days before critical listening.

Methodology was subjective listening for a length of time to familiarize myself with each cable and enjoy music before conducting A / B listening comparisons of short sections within each test track. A number of tracks were used (list to be provided later).

I realize the The Cable Company is a business concern but I have to acknowledge the benefit of their robust cable lending program. It has made cable choices easier, has taken the angst of a possible wrong choice out of the equation, and has led to much better and wiser final selections for me. I cannot overstate the value of taking advantage of it.

My need for a new USB cable was driven by the move from the Sonore microRendu and the Cardas adaptors I was using with it to the Sonore ultraRendu. The ultraRendu is not easy to set up behind the DAC (like the microRendu with the short adaptors is) which meant a USB cable of at least a half-meter to one meter length. I have also been upgrading my 2ch system over the past six months and felt it was time to test out other USB cables. Previously, Oyaide and Shunyata USB cables were in prior systems, however both are longer runs and I prefer having a 1M length for my current system.

I am familiar with both Audience and Cardas within my system. I am using and have been very happy with the Cardas Clear Reflection XLR ICs and Audience Au24 SX speaker cable.

I have not had prior experience with Purist, Stealth or Wireworld, though I have followed reviews and owner comments on Wireworld cabling.

This was my first lengthy and truly in-depth cable evaluation and also the first one that involved so many cables. Prior to this I had compared two cables at a time.

This was frustrating and time-consuming and early on, a very boring process. I also felt the urge to throw in the towel after the first few days.


BUT, BUT, BUT once I got into it, it was a very good experience and I have to say a terrific learning and growth experience for me. It has also furthered my understanding of audio and sound quality. In the end, it was a very rewarding exercise for me and retrospectively, time very well spent.

In a way, actually in much more than a way, it has brought me closer to my system --- in understanding it --- appreciating it --- enjoying it.


First phase ranking and results:

1st: Wireworld Platinum Starlight 7

2nd: Audience Au24 SE Plus

3rd: Purist Ultimate

4th: Cardas High Speed Clear


CAVEAT, CAVEAT, CAVEAT: This is in my system/room and based on my hearing abilities and preferences.


The caveats are important because after listening to all four of these cables, I can see why someone would pick any one of them for their system and needs and budget and be satisfied with the performance.


The Cardas was easy to identify as the fourth place finisher because the other three cables had a greater sweetness and refinement to their sound, greater air and bloom, and because the Cardas did not stand out based on any particular strengths, which the other cables exhibited. Some will value it’s consistency in not having any pronounced strengths. It’s Value = Quality/Price is high since it has the lowest price in the group tested.

Please note that this is the High Speed version which adds a ’special high performance data cable using silver-plated conductors’ per Cardas.


The Purist and the Audience were closer in sound signature to each other. With the Audience being closer to the Wireworld in it’s capabilities than the Purist.


Both cables are Fuller, Rounder, and Mid-Range Centric and came across more Forward with vocals.


What follows is relative to the Wireworld cable as it excelled in attributes over the Purist (to a greater degree) and the Audience (to a lesser degree).


Please know and make note that I’m not saying any of these cables are, for example, NOT detailed, or NOT transparent, or XXX (fill in the blank). This is a relative comparison.


I found the Purist to be lightly veiled, with less definition to the leading edge of the music, and it sometimes felt slow in timing. Transparency and resolution are not as strong as the Wireworld and micro-detail is lost, again relative to the Wireworld cable. Separation of musical information was not as strong as the Wireworld. It does not provide a window into the depths of the music like the Wireworld does.

It’s strong with the already mentioned fullness and roundness attributes as well as with the air and bloom it presents. Bass was the ’tubbiest’ of the four cables. I also found some inconsistencies with sound stage presentation, and at times larger than life images. I liked this cable enough to be open to considering the step up in the Purist line, but it was, relatively speaking again, the most inconsistent cable of the four.

I considered the possibility of it being somewhat defective or not run in completely. However, after hearing the 30th Anniversary version, I have to say that the cable was likely good and it’s performance is what it is, based on the house sound I was able to determine from the step up Purist cable.

If this sounds like damning information, it is not. Like I said, I was intrigued enough to be open to the 30th Anniversary version. I will say it really comes down to your system, your goals, and your preferences. I’m sure there are fellow audiophiles that are quite happy with this cable.


The Audience Au24 SE Plus (please note that this is the Plus USB cable which, per Audience, is an improvement over the SE version).


This is the first cable of the four that I really liked. The easiest way for me to describe it is that it brings most of what the Purist does well, without overdoing it as much, and it gets one closer to the Wireworld cable’s strengths.

It is more relaxed than the Wireworld.

It presents more musical energy than and with better definition than the Purist. It remains refined and delicate (not to the extent of the Wireworld but more so than the Purist) with great air and bloom. It is less detailed than the Wireworld, though it gets closer to it than the Purist.


If you are looking to split the difference between the Purist Ultimate and the Wireworld Platinum Starlight 7 the Audience Au24 SE Plus cable is the way to go.


The winner of the Phase 1 shoot-out is the Wireworld Platinum Starlight 7.


This is a well reviewed cable. On the flip side, those who have owned / demo’d it and have had concerns point to it being bright and lean and being a cable that requires careful system matching.


My impressions here are with the Sonore ultraRendu in the system (I’m giving something away here, but it is important to note that this cable was also evaluated with the Sonore Signature Rendu SE with even better outcomes which minimize or eliminate some of the weaknesses listed here).


For me, relative to and versus the other cables, the Wireworld cable nailed timing, clarity, resolution, detail, micro-detail, venue and ambient cues and information, and refinement. There is a delicate purity to it’s presentation that I noticed across tracks in combination with and contrast to a robust and engaging presentation of musical energy.


It offers a higher level of insight into the music and separates the musical information better than the other cables. Control is taut and better defined throughout the frequency range and the bass delivered is of much better quality and impact than the other cables. To my ears and assessment, timbre, tone and weight sound more ’real’ and palpable. The Wireworld also extends higher than the other cables, likely due to the level of transparency and resolution offered.


With the Sonore ultraRendu, it does have a leaner presentation than the Audience and the Purist. With certain recordings the sound was lightly fatiguing. It is less ’sweet’ sounding than the Audience and Purist cables. To my ears, it is the more honest cable in this comparison. For me, it is also the more musically satisfying cable of the four.



I agree about the big CAVEAT. The Yggdrasil has a less than optimal digital implementation. So your findings may be entirely related to digital problems of the DAC which are influencing your cable preference. If your components worked robustly then digital cables would not have an effect.

With such a long list of exhorbitantly expensive USB cables, you might consider upgrading components as a first step towards eliminating how digital cables affect your component performance.

According to Stereophile:

"Tested for its rejection of word-clock jitter with a 16-bit J-Test signal, the Schiit Yggdrasil had some problems"

Read more at https://www.stereophile.com/content/schiit-audio-yggdrasil-da-processor-measurements#LlqYiPu8IobviLI...

and

"While the processor’s analog circuitry is superbly well designed, its digital circuitry appears to have problems with high-level, high-frequency tones, and with the LSBs of 24-bit data"

Read more at https://www.stereophile.com/content/schiit-audio-yggdrasil-da-processor-measurements#LlqYiPu8IobviLI...
Hi David,

Nice writeup. Looking forward to part II.

I agree with Shadorne that USB cable preference can change according to the DAC it is paired with. The Yggdrasil is reported to be relatively laid back sonically so the more aggressive sounding USB cables (WW Platinum Starlight 7) will indeed provide a nice synergy if that is true. The rest of his post is closed-minded nonsense reflecting a lack of actual experience with different USB cables.

Dave
Interesting, I know someone who had the Purist and likes the new soon-to-be released SOtM USB cable the best.  He also preferred the Uptone USPCB to the Phasure Lush.
I'm not a USB cable type (preferring to deal with problems in better ways) 

but if you try anything, try the Lush cable
+1, dlcockrum.

One way to assume your DAC is immune to jitter and cable differences is to use cheap optical cable between your source and DAC 😉
Post removed 
I agree with dlcockrum about USB cables making a difference if the DAC is not able to fully reject noise, jitter and other parasitic extraneous factors. The rest of his post is close-minded nonsense reflecting a lack of knowledge about digital signals.
I use an inexpensive Chinese tube DAC and added a pair of 3uf Aura-T Teflon output coupling caps. I thought it was decent before the mod but it's quite a performer now and very revealing of the upstream signal.

My PC PS thread is for you daring DIYers if you really want to improve your computer sound. There are several pictures. Check it out:

https://forum.audiogon.com/discussions/computer-ps-upgrade-fuse-iec-teflon-cap

Regarding the OP: I A/B tested the Stealth USB-T vs the SR Galileo LE. The Galileo USB cable projected an exaggerated 3D soundstage. I felt that it was exaggerated because my system is already capable of a 3D stage. The SR cable made it a bit too 3D for my liking. The Stealth USB-T provided much better synergy for my set up. It performs well in all aspects for a "non active" cable. Another issue that I disliked about the SR cable is that it requires a power source for it's active shielding system. It adds to the rats nest behind my rig and those tuning bullets get hot as hell. The SR cable starts at $2k but it can do wonders for a system that lacks in 3D imaging. 
Reasoning vs listening, shadorne. Try listening for a change, you might learn something.

Dave

A Continuation of the USB Cable Comparison Audience / Purist / Stealth / Wireworld


NOTE: Please refer to my first two full posts for the detailed information that preceeds this and the next post.


PHASE 2.0


Mistakes can be wonderful. Rare, but it happens. It’s a story for another time. Short version: I was shipped a Sonore Signature Rendu SE (SR) without ordering or paying for it. Audiophile lottery, right?

After letting Sonore know and getting their okay to give the SR a listen, I did. And it stayed.

The day -- the Signature Rendu SE paired with the Wireworld (WW) cable went into my system -- turned into night and continued through the following morning. I did not sleep that night.

The entire system came together with such impact that the SR has not moved since that day.

I was also lucky with the timing of the shipment error. The SR was delivered a day after I had wrapped up the first cable comparison and the day the cables were to be shipped back. I extended the cable loan so I could evaluate the cables, the WW primarily, since it was the first place finisher, with the Signature Rendu SE.

Being able to learn so much about these cables, my system, and overall system performance from Phase 1 with the ultraRendu (uR) was fortuitous, timely and extremely valuable for the next round of cable comparisons.


Bottom line for me, with the SR in system and with a few days of run time on it, I still preferred the Wireworld Platinum Starlight 7 to the Audience Au24 SE-Plus.


The system sounded significantly better across the board with both cables, but the WW, to my ears presented musical information more correctly and with more: weight, air, detail, realism, and musicality than the "slightly less so" of the Audience. I preferred voice and stringed bass with the Audience (slightly fuller/rounder/forward than the WW) though when reflected upon, the WW sounds more accurate to my ears.

The Audience provided slightly less information and detail especially at the frequency extremes, sound stage presentation was slightly weaker than, and high frequencies were not as ’real’ sounding as the WW.

If I broadly summarize, I preferred the Audience slightly in the mid-range and upper bass, but prefer the Wireworld as a whole across the frequency range and for it’s coherence across the same (no overtly highlighted nor minimized sections). The previous strengths of the Wireworld, listed in the Phase 1 comparison, continued to shine through.

In other words, the first phase attributes / signature remained intact for both cables. [Please refer back to that post] [Also Note: With the SR in system, the WW lost the ’leanness’ and ’brightness’ and ’slight fatigue’ on certain recordings it exhibited with the uR].


Though the differences are slight, they were apparent to my ears and my musical enjoyment and most certainly worth it for me. In this case, from a cable that lists for less and is available for significantly less (street price) due to the common discounts. Again, no wrong choices here. System, system synergy and your preferences and music genres are all important in making the choice for yourself.

A Continuation of the USB Cable Comparison   Purist / Stealth / Wireworld

PHASE 2.1


The Purist 30th Anniversary and the Stealth USB cables arrived a week after the SR went into the system.


Changes from the Phase 1 comparison:

- Sonore Signature Rendu SE replaced the ultraRendu

- Schiit Yggdrasil DAC for the comparison of the Purist, Stealth, and Wireworld cables.

- Denafrips Terminator DAC for a second comparison of the Purist and Stealth cables.

The Cable Co. was kind enough to extend the first cable loan until I could get a feel for these three cables before sending the Wireworld (WW) back.


Second Phase Ranking and Results:


1st: Stealth USB

2nd: Purist 30th Anniversary USB

3rd: Wireworld Platinum Starlight 7 USB 2.0


It was clear with the Stealth in the system, that it was superior to the WW across the board. The Stealth basically brought more of everything the WW does well, as well as improving upon the qualities that the Audience and Purist Ultimate cables do well.

The purity, refinement, delicacy, detail retrieval, micro-dynamics/detail, venue insight I loved about the WW shifted in favor of the Stealth. The Stealth offered more reverb , better decay and much better bass and sheer energy. It made the WW sound ’less’ natural in direct comparison.

The differences when taken as a whole delivered greater emotion, realism, energy, insight and musical sensuality offering me a higher level of engagement, appreciation and emotional connection to the music.


With the Stealth in the clear lead, and some urgency to get the first four cables shipped back to The Cable Co., I did a quick comparison between the Purist 30th Anniversary and the WW. I preferred the Purist over the WW, but not by the same margin as the Stealth or for the same reasons. I will elaborate on the Purist’s performance which should allow readers to come to their own conclusions of the strengths and performance and sound signature of the WW and the Purist.


I’ll share the final comparison between the Stealth and Purist in my next post. Likely in a day or two.

What follows is a comparison between the Purist 30th Anniversary USB cable and the Stealth USB cable. This comparison, with it's focus on the Stealth (it's strengths and performance) as the first place finisher, also applies versus the Wireworld and the Audience cables.


My initial take / read on the Purist 30th Anniversary (P30) after it was added into my system was that it was better 'out of the box' than the Purist Ultimate (which is a step below in the Purist line-up).

The P30, however, needed more run-in time before I felt it had stabilized (this may have been relative to how 'broken-in' it was from the lending program). Highlighting this in case you go with the P30. You may have to give it some time.

It is a warmer and softer sounding cable, than the Stealth, and it's rounder and fuller signature is addicting and enjoyable. It is more forward with vocals. It is also superior to the Purist Ultimate across the board and minimizes the Ultimate's weaknesses. However, both have a very similar 'house sound' to them. The P30 is better, but it comes at a 60% premium over the Ultimate.

The Purist highlights or accentuates the main / primary focus of a music passage or recording section. It is there, fully bloomed, like a close up photograph of a flower, with the other details, as you pan further out and further in, lightly to more faded out and hazier. The Stealth balances that primary focus with all of the other musical information around that main section, without marginalizing it. It shows the flower along with more of the parts and layers and makeup of the flower as well as the stem / leaves / and plant that it is part of. It conveys a whole and comes across more natural and real while doing so. All the while maintaining it's grip and delivery of that 'main section / musical passage.'

The P30 does not resolve micro detail as well as the Stealth. This was interesting, because I noticed the micro-details with the P30, as in 'hey, there it is.' However, when I first listened to the same via the Stealth I missed those 'hey there-they-are details' initially. I was fairly sure that wasn't the case and in the process of figuring it out, I learned a very important lesson.

The micro-detail, more importantly the micro-micro detail, was very much present with the Stealth. It was conveyed as whole music, rather than a 'break' or 'hey there it is' piece of information / 'interruption' (as in "there is music there" vs a piece of information) which is why it was easier to miss. 


Audiophiles talk about that 'lost in the music' state...I think this helps convey this point. The Stealth was so good at this (this level of resolution and clarity) that the information did not stand out as an 'anomaly' (noticeable, if you may) but rather as a continuation of, and inherent part of the music.

I found the Stealth to have better timing, and tighter control than the P30.

Where the Stealth really stands out (vs the other cables) is in the level and amount of musical energy and pressure conveyed, the control and delivery of bass and the naturalness in how it conveys musical tension.

It manages to do this while being delicate and refined, and handles musical layering better than the other cables.

As I review my notes, I cannot see an area of music or 'audiophile descriptor' or a specific track segment that it was bettered in.


There is just 'MORE' to the music. A Greater Whole. I naturally preferred it and kept wanting this cable to go back into my system.

IT, I SHOULD SAY MY SYSTEM WITH THE STEALTH IN IT, is rendering music beautifully with a level of emotional engagement and realism I am thoroughly enjoying. Getting lost is now easy.

I ordered the Stealth USB in a 1M length from The Cable Company. It went in system on the 15th of Nov. and is nearly broken in.

@david_ten 

This is one of the better reviews/evaluations or whatever you want to call it of a cable or component that I've read in quite some time. Not everybody can convey their thoughts and feelings into words and I think you've done that exceptionally well here. I've experienced something similar lately where you get "lost in the music state" as you put it and you just want to stay there. It's amazing that with just one change of either a tube or a cable you can lose it. My problem is I'm constantly wanting to try new things instead of just being content with what is a musically and emotionally satisfying experience. That emotionally engaging experience is hard to explain to people and I think what separates those who just want to put a system together and "hear music" and those who get lost in the music. Very well done. 

Here is one example of a track I used to assess the cables. It isn’t a typical audiophile choice, but it served a number of purposes for my evaluation.

The differences between the cables are illustrative and reflective of the final outcomes.


’Giorgio by Moroder’ on Random Access Memories by Daft Punk


There is a long [1:50 min:sec] segment of Giovanni ’Giorgio’ Moroder speaking. He’s speaking at a venue (overlaid in the recording studio) with venue information, background voices/music/sounds, an electronic arpeggio beat and house music.

I like evaluating components / my system with voice segments. This particular track offers layered and very different types of information, essentially at the same time or very closely together. The highlight for me is Girogio’s spoken English with a slight accent.

A series of clicks are introduced into the track at the 1:30 mark. The track transitions to full on synth beat after the 1:52 mark. This evaluation was focused through the 2:00 minute mark.


The comparison resulted in the following rank order: Stealth > Purist 30th > Wireworld.


P30: The musical line lightly powers over his voice and there is a slight haze with less micro-detail vs the Stealth. There is slightly less background information when the track opens (the first few seconds). It’s presentation is superior to the WW and it moves closer to the Stealth in fullness and the energy conveyed (vs the WW). I found it a smidge slower and with slightly rounder definition than the Stealth.


WW: The bass is rounder than both the Stealth and P30. There is more movement to the clicks in the soundstage (with the P30 and Stealth - the clicks are more fixed positionally) and they are not delivered with the solidity and body of the Stealth. The WW sounds ’thinner’ and less palpable than the Stealth. The voice also comes across slightly faster / ’rushed’ perhaps. The WW did very well with background and venue detail and information.

The WW presentation is not as musically engaging. It doesn’t sound as real...in my notes, I label the sound with respect to the other two cables as ’artificial sounding’ for this specific segment.


Stealth: The conversation sounds very real, to my ears. The clarity/transparency delivers superior voice vs. the other two cables. The inflections, the breaks and starts, the breathing and subtleties of his voice and accent are clearer and more real. There is more body and weight to the voice, which also holds up at lower volumes (vs the other cables).

As a very specific example within this track segment and the voice part of it: the ’trill’ in the ’R’ in when he says his own name ’Giorgio’ at ~1:50 is expressed better.

The venue information and background voices and noises are presented better than the other cables. The bass line is both tighter and more musical throughout and doesn’t overpower Giorgio’s voice. The timing or pace of the music is the best among these cables. It has the more impactful and musically engaging presentation among these three cables.


The Stealth puts me more ’There’ and with more of an ’It’ or ’Wow’ factor, when I compare these cables. The Purist 30th Anniversary is a close second. The WW a more distant third, with this specific track segment.


For those interested, here is a link to more information on this recording, courtesy Wikipedia:

https://en.wikipedia.org/wiki/Giorgio_by_Moroder

Most companies recommend 1.5 meters for USB. I know Wireworld suggests 1.5 meters as the optimal length. Does Stealth suggest 1.5 meters as optimal? I noticed that the WW was 1 meter, do you think the results would differ if the WW was 1.5 meters?
@ricred1   Good question and point.

I've heard smaller than 1M lengths for some USB cables being best. I've also read about avoiding longer lengths for some types of interconnect cables.

I did not ask the question specifically of any of the the cable companies represented in this comparison.

Stealth's FAQ section does not address cable length. It does address a number of other issues. I reached out to Audience for a separate question, and their response did not address cable length.

I requested equal lengths of cabling from The Cable Co. but they were not able to match all, via their lending program. 

When I was ready to purchase the Stealth I asked The Cable Co specifically about the length (the demo was 1.5M) because I did not want any surprises with a new length. I was informed that there would be no sonic difference or penalty or upside between the 1M to 2M lengths of Stealth.

I chose the 1M length because I don't like having excess cable hanging off the shelves and also paying for a length I am unlikely to need, in this application.

I cannot, from memory, discern any difference in the performance between my Stealth 1M and the 1.5M demo. 

Have you found differences? It will be good to know if you have. Thanks.
@dlcockrum  @t_ramey  @knownothing   

Thank you for your kind words. Good to hear you like the write-up. It's been exhausting and time-consuming. So the 'thumbs up' is appreciated.
This may or may not be helpful RE cable length for USB since this article is focused on S/PDIF.

https://positive-feedback.com/Issue14/spdif.htm

I would suggest reaching out to Steve Nugent who posts here as audioengr
I also want to thank all who have posted. Thank you for your interest and your thoughts and suggestions.
Very nice information and time taken to compare and write this all up.  I personally do not use a USB cable so I have no opinion on any of the cables although I have used the different brands in other applications and have found a few similar results, go figure.  Anyway it all comes down to what you prefer anyway so as long as you are satisfied and happy, and enjoy listening, then that is what matters most.  Happy Listening.


Man, that’s a lot of money to spend on a USB cable. But I’m also a believer in spending money on cables, so I don’t have a problem with it. 

In the much less expensive category, I would throw in this one. 
Oyaide Neo d+ Class A USB 2.0 Cable
http://www.theabsolutesound.com/articles/oyaide-neo-d-class-a-usb-20-cable/
 I can hear a difference but haven’t tried what you have. 
My USB comparison is ’published’ here:

https://usbcablecomparison.blogspot.com/

It’s an easier and hopefully more coherent read as one full / complete write-up (versus the multiple posts above).

I will be evaluating another USB Cable compared to my previous reference, the Stealth USB , next week.
1 Could you identify them blind?
2 What are the statistics on repeat identification?
@willemj,

Thanks for posting the link for the upteenth time. 

This thread is clearly intended for the benefit of those believe in ‘cable matters’ and are able to discern the audible differences with each respective cable. 

Cheers! 
What that actually proves is you can prove anything with measurements. All you need to do is find the test that proves your argument. It’s easier than falling off a log. In fact this all proves my point - the results of all tests are unreliable.
Post removed 
@david_ten 

Any chance you’ve had an opportunity to try the Black Magic usb cable from Mad Scientist?
@t_ramey  I have not. I hear great things about his product line. 
And his connection with KLE Innovations (another terrific line of cables) is notable.

Are you looking into the Black Magic USB cable? 

Best, - David.
@david_ten 

Since reading your review of the Stealth I’ve always had it in the back of my mind but the price is a bit steep and have yet to see a used one come up for sale. 

I currently have a Phasure Clarixa and it’s great but some day would like to venture out with other cables. The Black Magic is half the cost of the base Stealth so I wonder how close it comes to it. 
Have you heard of the Intona USB cable?
It seems to be relatively new and is made by the same German company that makes the Intona USB Hi Speed Islolator.

I can't vouch for it but it looks promising and is cheaper than what you've tried so far.

All the best,
Nonoise
Have been testing usb cables for a year now and have also concluded that the stealth is the most balanced and natural. It almost sounds like a high end rca cable. Amazing speed, balanced throughout the spectrum, soundstage is endless and very much according to the recording. No exaggerations just ultra high detail in an all natural format, in all dB levels. 
It surely is an end game usb cable imho, and does not require almost any break in, in about 50hrs it was all set in. Would recommend to get 1.5m length, as tested the 1m and found to 0,5m difference to remove any digital remains if any. Now my Aurender and Gryphon dac are in pure harmony. For the record it is a usb t select. 
I’ve had the Stealth USB-T in my possession for several weeks now and have compared it to the Phasure Clarixa I had been using as well as the Mad Scientist Black Magic that I recently picked up. 

The Clarixa has been a great cable but always thought it was just a tad etched in its tone and wondered if trying a new cable would alleviate that. The Black Magic improves on this tone and provides a holographic soundstage that is really fun to listen to. I like that it gives voacals and stringed instruments an ethereal quality that I think befits it’s name of Black Magic. For the price I think the Black Magic is exceptional and am glad I took a chance on it. 

The Stealth seems to allow more information through and definitely has a bigger and wider soundstage than any other usb cable I’ve tried. The natural tone of the Stealth while still giving plenty of dynamics and detail is what I like the most about it. While it may not be as holographic as the Black Magic I think that instruments sound more real with the Stealth. The strike of a piano key and the sound of a cymbal definitely gives a more vivid but real sound that’s make me glad I ventured out and tried this cable. Everything I wanted to improve on the Clarixa got improved. The Stealth has a certain “magic” of its own and is hard to really explain but reminds me back to david_ten’s remarks about getting lost in the music. Not one thing stands out but taken as a whole it’s a pretty cool thing. 

Thanks David for sharing your experiences here and shining some light on this Stealth brand that I’m kinda surprised isn’t talked about more. Good stuff.
@t_ramey Thanks for sharing your findings and differences between your three USB cables. Good stuff, indeed!!! I’m glad it worked out.

As @tinian points out, it is "the most balanced and natural" cable in his comparative findings as well.

Your post, and his, sheds light on the Stealth USB being a special cable worth consideration.
@david_ten  Unlike tinian though my usb-t cable took a little over two weeks for me to fully realize how good this cable is. It was too laid back at first and I was getting a little disappointed it might not be what I had hoped. But then it opened up and showed how dynamic and detailed it really is but in a very natural and beautiful way. 

Feels weird to have to come to a cable thread where people act like adults and are civil towards one another. Hope I didn’t just jinx it... :)
The full break-in experience mirrored yours. Just short of two weeks, in my case.

For those that may be following, I did find the cable enjoyable and performing well after a couple of days of break in.
Very comprehensive review.  Have not thoroughly done anything on USB cable.  But your writings reflected my personal experience when comparing cables.  

Thank you for the contribution!
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If you don't mind spending a bit more money :-) I would recommend going for the T (tunable) version of the Stealth USB cable. It will allow you to change for your particular DAC or speakers. (However, if you are the obsessive type it may not be a good idea.)
Did a recent comparison of a lot of usb cables mentioned in this thread, as well some Nordost ones.

I felt that the Audience, Nordost Heimdall 2, and Wireworld platinum were all on the same level and were a matter of system matching and taste.

Stealth, Purist 30th, Prana, and Nordost Tyr 2 were all a step up....also a matter of system matching and taste.

And unfortunately, in my system the Nordost Valhalla 2 USB was in another league. A clear step up from the rest.  That price tag though... ugh