[romaz]

@Romaz, good post! However, I guess at the end of the day I wasn't so much hanging any hats on Amir's findings, but more of how any audio input is supposed to live up to DAVE. These are my uneducated thoughts (though I'm becoming more educated, slowly, since I had never put much thought into the science of audio). That is, if we go by the principle of "garbage in, garbage out," then it would seem to me, in my limited understanding, that every frequency that we put into DAVE, even if said frequency is music or signal is below the threshold of human hearing, it would still get in the way of the audio cues that the brain picks up beyond what we can hear. In other words if the DAVE is so sophisticated to have no noise modulation at -350db (which I believe to be true), yet there is induced noise from our signal at -250db, wouldn't that cover up the subtle cues that only the brain can assimilate at -350db?

Know this: I'm not calling out anybody or any product. Neither is that my future goal. I'm merely seeking answers in an audio world awash with often seemingly conflicting information.

The next question goes hand-in-hand with first, to wit, Rob tests the creation of the DAVE with music that all of us have access to. Rob heard sound below whatwe are believe the war can hear...But Rob is also getting some sort of junk in his playback system, yes? I mean, he has to. So, do these artifacts actually form a barrier between the -250db and the next 100 -350db. Some kind of junk is there. As far as I know, there's not a single transport that is so clean that no crap is injected at somewhere between 127db and -350. If there was, we would all own that transport.

And would Rob need all of the audiophile cables and interconnects, power supplies and fancy software to arrive at his design? Is that how he heard below the normal span of hearing to where we are now able to tap into the power of how we REALLY hear, using the mind?

In the other hand, I'm thinking, hey, even if there is crap in the line, it's not like it's a solid barrier like a steel wall, right? It would be more like mesh, perhaps intermittent, maybe a few spikes here and there, but not wholy rigid.

There must be a fallacy in my logic. I know there must. And none of this is because the DAVE was bright on my tricked out computer, yet better on my Windows 10 laptop. Or...well...Maybe a little, because now I'm searching for a better transport. But really it's because I'm trying to make out why the DAVE sounds so good, and what can get in the way, under the best AND worst case scenarios.

(Typing from my phone sucks.)

My ultimate point is this -- the only golden ears that should matter are our own and the only valid tests that should matter are what our brains tell us is good.  As has been said so many times, if it sounds good, then it is good.  What I have problems with (and this has happened plenty of times on this thread) is when people make summary judgements against a product like the DAVE never having really listened to it.
 
Rob can speak for himself but what I have found is this -- because the DAVE is so revealing, it will often reveal the weakness or the limits of anything connected to it.  Along this line, I have also found that the DAVE has so much potential not yet tapped because of the limitations of our ancillary gear that if you are willing to go to the nth degree to improve your system, the DAVE will scale as high as you take it.  I am continually amazed by this.

 

[Rob Watts]

Well, yes! Yes it does!

But here is my fundamental lack of knowledge. Okay, so the DAVE has no noticeable noise floor modulation, dipping all the way to -350db, correct? If my understanding is wrong, please correct me. But, introducing a noisy signal, even if it's theoretically below the range of human hearing, let's say what the review demonstrated at -127db or there abouts, wouldn't that pollute the DAVE's output, meaning that all data going into the DAVE is a pollutant? Or is my understanding totally flawed?

Or do the flaws coming with the signal must be at or below the original signal?

OK, just to clarify, as the issue of -350 dB performance has created some confusion. This is the digital performance of the noise shaper. And to do this I set up a Verilog simulator test; you supply the Verilog noise shaper module (this is the actual design of the noise shaper, coded in Verilog which is a way of creating digital logic using coding) together with some data as the input, then the simulator runs the test and records the output data. I then take this output data and do FFT's on it, which are the results I published before. Now although the term simulation is used, it is completely exact - you feed the noise shaper this data, the output is guaranteed to be that output. So it is a perfect measurement of the digital performance of the noise shaper. But of course, it is only the digital domain performance - in reality the DAC actual analogue outputs will be very much worse than this.
 
So why is 350 dB performance important? 
 
Its not the noise, as this is about 64 bit performance, and a 24 bit audio file source will be a trillion times noisier than this.
 
What is key to why this is important is about how noise shapers work. Now if you supply a noise shaper with a signal, there comes a point where the signal is so small that it can no longer change the noise shaper output sequence - so a noise shaper becomes blind to tiny signals. What this means in practice is that as a signal gets smaller it gradually gets attenuated in level. Eventually the signal is so small it has no effect on the output noise shaper bitstream, and so ultra small signals are lost. Now the noise shaper noise floor gives you an indication of when this will happen - signals below the noise shaper noise floor will get attenuated and eventually completely lost. So that is why I now run a test to see how well the digital path functions with a -301 dB test signal - it must reproduce that perfectly with no change in amplitude.
 
Now small signal accuracy is very important for depth perception, as small echo cues tells the brain that a sound is further away. So if these signals are being attenuated its easy to see that you won't perceive depth properly.
 
But what is truly bizarre is that any attenuation, no matter how small, has an impact in how the brain calculates depth; indeed I am now of the opinion that there is no limit to how accurate small signal accuracy needs to be. If you think about that, that is extremely odd that the brain can be so sensitive. And we are not talking about effects that are hard to hear - its very obvious and easy to hear.
 
So the 350 dB performance is only in the digital domain, and its not about noise or noise floor modulation but about how accurate small signals are being preserved in terms of their amplitude.
 
Rob

 

[Mavwong]

I once judge urendu with ifi, BIG mistake. So I could say ifi sucks, I should have not include ifi ps and save myself a good meal.
 
 
 
Quote:

Am I missing something or does that 'review' only show that the iFi power supply sucks?

 

[Sunya]

 
What is key to why this is important is about how noise shapers work. Now if you supply a noise shaper with a signal, there comes a point where the signal is so small that it can no longer change the noise shaper output sequence - so a noise shaper becomes blind to tiny signals. What this means in practice is that as a signal gets smaller it gradually gets attenuated in level. Eventually the signal is so small it has no effect on the output noise shaper bitstream, and so ultra small signals are lost. Now the noise shaper noise floor gives you an indication of when this will happen - signals below the noise shaper noise floor will get attenuated and eventually completely lost.

 
The question is how small can be the smallest signal encoded in a 24 bit file; leaving aside the noise level of mic preamps, the best studio AD converters have a dynamic range not greater than 21-22 bits. So if the smallest signal would theoretically be at -130dB how come the DAC's noise shaper performance needs to go down to -350dB? Is this overhead needed for the noise shaper to work properly on -130dB signals?

 

[Crgreen]

I've been using PS Audio's LANRover with the DAVE, with good results.

 

[romaz]

As many that follow this thread know, there have been comments made recently about how little difference certain people found with the DAVE compared to another DAC.  This has led me to wonder if this is because expectations were unrealistic or because a person's system wasn't resolving enough?  You could also consider the possibility that a certain person doesn't have a discerning enough ear but I'm less inclined to believe this as even my non-audiophile wife can easily discern between the DAVE and any other DAC I have had in my home for testing.
 
As someone recently reminded me, I had posted once that what is connected after the DAVE can make a bigger difference than what is connected before the DAVE and I continue to believe that this is true.  While the DAVE is the most resolving source I have ever experienced, speakers and headphones still make a bigger difference.  While there are some who can't readily appreciate the differences between DACs, I don't believe anyone would have trouble differentiating between the HD800, HE-1000, LCD-3 or Abyss in a blind test.  
 
But what about cables?  For some, this remains an overlooked or underestimated component.  Having looked at the component list of a recent poster who claimed he couldn't tell much difference between the DAVE and another DAC, I was surprised to see he had very expensive and well-regarded speakers and monoblock amplifiers but was using a pair of 20-year old interconnects of uncertain reputation.  I suspect my wanting to discuss the impact of cables will cause some to dismiss this post.  I, too, belonged to this group once.  In fact, before the DAVE, I struggled to hear much difference among cables.  As I previously mentioned, however, because the DAVE is so revealing, the differences among cables are more easily discerned with the DAVE.  Looking at it another way, if you are going to maximize the potential of your DAVE, cables absolutely matter...at least that is the premise I would like to now prove.
 
Well, I decided to look at the impact of interconnects with the DAVE more formally to see just how much they matter and how they might affect the resolution of a transducer like the HE-1000 or Abyss when connected to the DAVE.  If you are to believe the Blue Jeans Cables website (makers of no-nonsense budget cables), they believe that "The most important attributes of a line-level unbalanced audio cable are (1) shielding, and (2) capacitance."  And that's it.  At a fundamental level, this is probably true although they seem to believe that the measures they undertook to achieve "an extremely low capacitance of 12.2 pF/ft" made for an adequately competent interconnect.  Indeed, I bought into this idea and for years, I used Blue Jeans Cables RCA interconnects.  
 
As I made upgrades to my system, it only made sense to also explore upgarding my cables and periodically, I did so.  I tried a variety of interconnects, both single-ended and balanced, from manufacturers like Cardas, AudioQuest, Audience, Morrow and JPS Labs before settling on a set of Antipodes Reference RCA ICs when I bought my TotalDac.  While I could hear differences, especially between the inexpensive Blue Jeans ICs and the Antipodes, the differences somehow were nothing to write home about and it seemed to be more about tonal differences than resolution differences.
 
For this set of tests, I brought out my old pair of Blue Jeans Cables RCA interconnects ($30) as a baseline comparator.  I decided to specifically look at the impact of metallurgy with respect to resolution, specifically copper vs silver vs silver/gold alloy.  I also wanted to assess the impact of standard (unspecified) purity vs UP-OCC (Ultra Pure-Ohno Continuous Cast) as well as the impact of different dielectrics (teflon vs cotton) and so I borrowed several sets of interconnects from Dave Cahoon, owner of Zenwave Audio.  Thrown into the mix was a pair of HFC CT-1E interconnects.  All were 1 meter in length except for the Blue Jeans IC which was 0.5 meters.
 

 
Here is my methodology:
 
As some of you are aware, I have been testing a prototype headphone device by High Fidelity Cables that magnetizes the analog headphone signal before it is sent to my headphone via my Spore4 headphone cable.  For those not aware of what this looks like, here it is sitting to the right of my DAVE:
 

 
This is a passive device with the both RCA and 6.35mm inputs on the back:
 

 
This has proven to be a helpful device in this comparison of various interconnects.  Here is what the setup looks like connected to various interconnects:
 


 
Obviously, both my DHC Spore4 headphone cable and this HFC magnetic headphone device will have some impact on SQ although they were kept constant in the chain.  The only variable was the interconnect.
 
The interconnects used were as follows and my findings are included as well:
 
1)  Blue Jeans Cables RCA LC-1 interconnect ($30)  -  Unlike the other copper cables, these cables utilize an unspecified purity of copper but at this low price, it is undoubtedly not UP-OCC grade.  It utilizes a foamed polyetheylene dielectric designed for high flexibility and easy routing.  It produces a nice rich, thick tone -- beautiful, in fact.  Upon first listen and paired with the HFC headphone device + Spore4 headphone cable, it sounded very pleasing.  Easily a bargain at $30 and in the absence of any comparison, I could be lulled into thinking this is a very acceptable sound.  Once compared to any of the other cables, however, it became evident how slow and syrupy this cable is and how this cable keeps secrets.  This cable paints the broad strokes well but will leave you wanting when it comes to the fine details.  
 
2)  D2 ($499) -  This is a hand-made interconnect that utilizes UP-OCC grade copper and is the purest grade of copper you can source.  It utilizes 2x Neotech 20 gauge UP-OCC cotton-insulated wire for signal and 2x Neotech 20 gauge UP-OCC cotton insulated wire for ground.  It incorporates high-quality WBT 0102 platinum-plated silver RCA plugs.  At its asking price, this cable is a steal and compares very favorably to the much more expensive Audience AU24SX that I listened to recently which lists for $1,850.  For those unfamiliar with what OCC is, it is a casting process developed to defeat annealing issues and virtually eliminates all grain boundaries using a unique patented process.  It yields a single cystal of copper (or silver) up to 125 meters in length resulting in an unimpeded free path for the best possible signal transfer.  UP-OCC (where UP stands for Ultra Pure) provides copper (or silver) with the least possible oxides and other impurities resulting in a purity of up to >99.99998% (6 nines) where standard oxygen free copper usually has a purity of only >99.99% (4 nines).  How does it compare against the Blue Jeans IC?  It shares a similar rich and pleasing tonality but is immediately smoother and considerably better resolved.  Using the same 20-second segment of Mahler's 7th (16/44) and Almost Blue by Diana Krall (16/44), there is more air around the instruments and around Diana's voice.  Consequently, details are more easily discerned.  It's almost as if I went from 320k MP3 to lossless 16/44.   
 
3)  Duelund Silver IC ($425) - This is a unique presentation of silver in a cable developed by the late Danish legend, Steen Duelund, where a thin round silver wire is wrapped in cotton and impregnated in oil. It is said to result in a smooth silky sound with copper-like warmth yet with the resolution of silver.  I found this to be an apt description with a warm tonality somewhere between the Blue Jeans and the UP-OCC Copper IC but more resolving than either.  For those looking to tame a bright system but not wishing to compromise too much on resolution, this one is a good choice.  It doesn't have the rich full body of the Blue Jeans but it has beguiling speed and finesse.  Those wishing for a "vinyl-like" sound will probably feel most at home with this cable.  
 
4)  D3 ($549) - This cable incorporates an alloy comprised of both silver and gold but unlike other alloys that incorporate this mixture, this Neotech product is made using the OCC method.  It is said to have the positive attributes of silver in terms of speed and resolution  but where silver can sometimes be criticized for sounding lean and bland, the gold is supposed to add more body and more accurate tone.  To my ears, this cable easily out-resolved the previous cables.  The presentation was more forward, especially compared against the Duelund Silver cable.  The speed and dynamics with this cable is just amazingly good.  The tonality is not as thick compared against the Blue Jeans but is more accurate.  The timbre of the piano on the Krall track is definitely more spot on.  My engagement with Mahler is now considerably raised.  All the players are much much better discerned and the depth of detail is unmistakably better compared to the previous cables.  
 
5)  D4 ($1175) - This is Dave Cahoon's best cable.  While it also incorporates an alloy that combines both silver and gold using the OCC method, he commissioned Neotech to create a proprietary mixture of silver and gold for him that is not available to the public.  He refuses to divulge what this mixture is and considers it his intellectual property.  Signal wire is comprised of 4x28 guage wire per cable in a cotton dielectric.  Unlike the D3 which utilizes 18 gauge UP-OCC copper wire for ground, the D4 utilizes 6x26 gauge UP-OCC silver wire for ground.  How does it sound?  LIke the D3 but discernably better.  The gap is not as large as the D3 vs the cables before it but there is a definite upgrade in resolution.  Tone is fuller and more saturated suggesting a greater gold content.  I wouldn't call this cable warm like the copper wires nor would I call it cool or sterile.  While it has more body than the D3, it does not sound as if it comes at the compromise of speed.  If anything, there appears to be more transparency and more resolution.  Compared against the Spore4 by itself (which is made of UP-OCC silver with no gold), there is a definite increase in tonal body and richness with the D4 and perhaps the timbre is more accurate whereas the Spore4 by itself presents a more airy treble and fleetness of foot.  The Spore4 layers a bit better but the D4 has a more organic flow.  If you are a fan of DHC, as I am, you know that Peter Bradstock is not a believer in silver/gold alloy wire and in fact, he makes fun of it on his website.  Having now heard it and directly compared it, there is a real argument for this mixture.  In the end, it comes down to personal preference but I actually very much prefer the combination of D4 > HFC magnetic device > Silver Spore4 over the Silver Spore4 by itself.  
 
6)  HFC CT-1E ($2800) - Those of you who have followed my posts know that I have a bias for HFC cables and I will readily admit it.  I just like what this magnetic technology does and nothing I have heard has come close to matching it.  I actually own a higher end CT-1UR interconnect that retails for $8900 (that I was able to find used at a considerable bargain) that blows this one away but I went with the lower end CT-1E so that the comparison would be on a more even footing.  How does it compare?  Trying to be objective, it is easily the most resolving of all of the cables and very easily discerned on blind testing.  The level of clarity is just at another level.  The timbre of the piano in the Krall track is the most convincing yet.  The decay is the most natural where it lingers when it is supposed to linger and rapidly dissipates when there shouldn't be any overhang.  The treble has a sparkle to it but yet it isn't bright and never harsh.  As for the Mahler track, the players are solidly in position on the soundstage and you have a much more confident sense of what instruments are playing.  The speed of this cable is just amazing.  
 
This comparison has led me to be curious about other very expensive cables like the Transparent Magnus Opus, the cable of choice for many dCS and MSB owners.  The top end Magnus Opus RCA interconnects can sell for up to $35k a pair.  Having spoken to a Transparent dealer at length, it was interesting to find that as you go up the chain from Reference to the XL to the Opus and then the Magnum Opus, the main difference has more to do with improved mechanical resonance control and build quality.  With the top end Magnus Opus, the cables are custom built and tuned to match the electronic and physical details of the components used and the listening environment.  Transparent even comes to your home and performs the termination soldering on site.  According to the dealer, as you go up the chain from the Gen 5 Ultra to Magnus Opus, the tonality doesn't change although control, low-frequency articulation and depth improves.  Of interest, Transparent prefers the tonality of copper and made a conscious choice to avoid silver in any of their cables.
 
Having directly compared the resolving ability of the purest form of copper vs silver, to my ears, it's no contest.  Which tonality you prefer is a matter of personal preference but when it comes to resolution, silver easily wins.  What is enlightening about this comparison is that the DAVE revealed the differences so easily, something that I doubt I could have so easily discerned with my previous systems.  Here is proof.  As I often do, especially when I'm not sure I can really hear a difference, I resort to blind testing.  In this exercise, this was easy to perform and my wife was able to swap cables within a matter of 30 seconds.  When I typically blind test different components, I usually do an A/B comparison.  When I feel the differences are quite obvious, I might even do an A/B/C comparison but never before have I done an A/B/C/D/E/F/G comparison.  That's right, instead of comparing only 2 cables against each other at a time, I blindly compared all 6 cables against each other at the same time.  My wife started with one cable of her choosing and I wrote down certain characteristics after listening to 20-second snippets of 2 different tracks.  Beside these snippets, I would jot down which cable I thought I was listening to.  She would then move on to the next cable and the next until I heard all 6 cables.  There were a couple of instances when I thought I was listening to a certain cable only to change my mind after hearing the next cable and I allowed myself this prerogative.  At the end, I scored 100%.  While some would suggest I have some magical golden ear, I would suggest that I'm not that good.  The better explanation is that the DAVE is that good, that it could differentiate the characteristics of different cables this well.  With the Blue Jeans Cable, would I be able to differentiate the DAVE against the Mojo?  I highly doubt it.  Could I do it with the HFC CT-1E or even the Zenwave D4, I'm pretty sure I could and I suspect you could, too.  With the DAVE, do cables matter?  Absolutely.

 

[TheAttorney]

Another very informative and thought provoking comparison romaz.
 
Whilst I don't doubt that the downstream cables matter most for DAVE, I also feel that the upstream cables can also have an effect, at least for the optical and USB cables I've tried. I'll try to quantify that at a later date - too many other changes to my system for me to be conclusive about this. 

 

[TheAttorney]

Am I missing something or does that 'review' only show that the iFi power supply sucks?

 
The iFi power supply does not suck. It is a perfectly acceptable entry point to the microRendu world - that has given me the best input so far into my DAVE.
 
It is no surprise that bigger power supplies (that cost multiple times more than the iFi) will give further improvements. But, at less cost than a typical audiophile fuse, the iFi will give a fair taste of better things to come.
Of course, there are many variables with the incoming mains quality that could give different results for different people.
 
In theory, the upcoming LPS-1 should be largely independent of the upstream power supply. So in theory, the iFi may end up being effectively as good as a mega bucks power supply - in terms of feeding the LPS-1. I suspect it won't be quite as simple as that, because nothing is perfect, but nothing is proven yet.  
 
Until that point, the iFi is a reasonable low cost way of waiting for the LPS-1 situation to pan out

 

[EVOLVIST]

OK, just to clarify, as the issue of -350 dB performance has created some confusion. This is the digital performance of the noise shaper. And to do this I set up a Verilog simulator test; you supply the Verilog noise shaper module (this is the actual design of the noise shaper, coded in Verilog which is a way of creating digital logic using coding) together with some data as the input, then the simulator runs the test and records the output data. I then take this output data and do FFT's on it, which are the results I published before. Now although the term simulation is used, it is completely exact - you feed the noise shaper this data, the output is guaranteed to be that output. So it is a perfect measurement of the digital performance of the noise shaper. But of course, it is only the digital domain performance - in reality the DAC actual analogue outputs will be very much worse than this.

So why is 350 dB performance important? 

Its not the noise, as this is about 64 bit performance, and a 24 bit audio file source will be a trillion times noisier than this.

What is key to why this is important is about how noise shapers work. Now if you supply a noise shaper with a signal, there comes a point where the signal is so small that it can no longer change the noise shaper output sequence - so a noise shaper becomes blind to tiny signals. What this means in practice is that as a signal gets smaller it gradually gets attenuated in level. Eventually the signal is so small it has no effect on the output noise shaper bitstream, and so ultra small signals are lost. Now the noise shaper noise floor gives you an indication of when this will happen - signals below the noise shaper noise floor will get attenuated and eventually completely lost. So that is why I now run a test to see how well the digital path functions with a -301 dB test signal - it must reproduce that perfectly with no change in amplitude.

Now small signal accuracy is very important for depth perception, as small echo cues tells the brain that a sound is further away. So if these signals are being attenuated its easy to see that you won't perceive depth properly.

But what is truly bizarre is that any attenuation, no matter how small, has an impact in how the brain calculates depth; indeed I am now of the opinion that there is no limit to how accurate small signal accuracy needs to be. If you think about that, that is extremely odd that the brain can be so sensitive. And we are not talking about effects that are hard to hear - its very obvious and easy to hear.

So the 350 dB performance is only in the digital domain, and its not about noise or noise floor modulation but about how accurate small signals are being preserved in terms of their amplitude.

Rob

Thanks, Rob. I'm sure I'll probably look back one day on my lack of knowledge and laugh.

I love the DAVE. I have to work out a few transport issues, but other than that I'm listening and learning, but above all enjoying the music.

 

[Beolab]

Spoiler: Quoted post

  As many that follow this thread know, there have been comments made recently about how little difference certain people found with the DAVE compared to another DAC.  This has led me to wonder if this is because expectations were unrealistic or because a person's system wasn't resolving enough?  You could also consider the possibility that a certain person doesn't have a discerning enough ear but I'm less inclined to believe this as even my non-audiophile wife can easily discern between the DAVE and any other DAC I have had in my home for testing.
 
As someone recently reminded me, I had posted once that what is connected after the DAVE can make a bigger difference than what is connected before the DAVE and I continue to believe that this is true.  While the DAVE is the most resolving source I have ever experienced, speakers and headphones still make a bigger difference.  While there are some who can't readily appreciate the differences between DACs, I don't believe anyone would have trouble differentiating between the HD800, HE-1000, LCD-3 or Abyss in a blind test.  
 
But what about cables?  For some, this remains an overlooked or underestimated component.  Having looked at the component list of a recent poster who claimed he couldn't tell much difference between the DAVE and another DAC, I was surprised to see he had very expensive and well-regarded speakers and monoblock amplifiers but was using a pair of 20-year old interconnects of uncertain reputation.  I suspect my wanting to discuss the impact of cables will cause some to dismiss this post.  I, too, belonged to this group once.  In fact, before the DAVE, I struggled to hear much difference among cables.  As I previously mentioned, however, because the DAVE is so revealing, the differences among cables are more easily discerned with the DAVE.  Looking at it another way, if you are going to maximize the potential of your DAVE, cables absolutely matter...at least that is the premise I would like to now prove.
 
Well, I decided to look at the impact of interconnects with the DAVE more formally to see just how much they matter and how they might affect the resolution of a transducer like the HE-1000 or Abyss when connected to the DAVE.  If you are to believe the Blue Jeans Cables website (makers of no-nonsense budget cables), they believe that "The most important attributes of a line-level unbalanced audio cable are (1) shielding, and (2) capacitance."  And that's it.  At a fundamental level, this is probably true although they seem to believe that the measures they undertook to achieve "an extremely low capacitance of 12.2 pF/ft" made for an adequately competent interconnect.  Indeed, I bought into this idea and for years, I used Blue Jeans Cables RCA interconnects.  
 
As I made upgrades to my system, it only made sense to also explore upgarding my cables and periodically, I did so.  I tried a variety of interconnects, both single-ended and balanced, from manufacturers like Cardas, AudioQuest, Audience, Morrow and JPS Labs before settling on a set of Antipodes Reference RCA ICs when I bought my TotalDac.  While I could hear differences, especially between the inexpensive Blue Jeans ICs and the Antipodes, the differences somehow were nothing to write home about and it seemed to be more about tonal differences than resolution differences.
 
For this set of tests, I brought out my old pair of Blue Jeans Cables RCA interconnects ($30) as a baseline comparator.  I decided to specifically look at the impact of metallurgy with respect to resolution, specifically copper vs silver vs silver/gold alloy.  I also wanted to assess the impact of standard (unspecified) purity vs UP-OCC (Ultra Pure-Ohno Continuous Cast) as well as the impact of different dielectrics (teflon vs cotton) and so I borrowed several sets of interconnects from Dave Cahoon, owner of Zenwave Audio.  Thrown into the mix was a pair of HFC CT-1E interconnects.  All were 1 meter in length except for the Blue Jeans IC which was 0.5 meters.
 

 
Here is my methodology:
 
As some of you are aware, I have been testing a prototype headphone device by High Fidelity Cables that magnetizes the analog headphone signal before it is sent to my headphone via my Spore4 headphone cable.  For those not aware of what this looks like, here it is sitting to the right of my DAVE:
 

 
This is a passive device with the both RCA and 6.35mm inputs on the back:
 

 
This has proven to be a helpful device in this comparison of various interconnects.  Here is what the setup looks like connected to various interconnects:
 


 
Obviously, both my DHC Spore4 headphone cable and this HFC magnetic headphone device will have some impact on SQ although they were kept constant in the chain.  The only variable was the interconnect.
 
The interconnects used were as follows and my findings are included as well:
 
1)  Blue Jeans Cables RCA LC-1 interconnect ($30)  -  Unlike the other copper cables, these cables utilize an unspecified purity of copper but at this low price, it is undoubtedly not UP-OCC grade.  It utilizes a foamed polyetheylene dielectric designed for high flexibility and easy routing.  It produces a nice rich, thick tone -- beautiful, in fact.  Upon first listen and paired with the HFC headphone device + Spore4 headphone cable, it sounded very pleasing.  Easily a bargain at $30 and in the absence of any comparison, I could be lulled into thinking this is a very acceptable sound.  Once compared to any of the other cables, however, it became evident how slow and syrupy this cable is and how this cable keeps secrets.  This cable paints the broad strokes well but will leave you wanting when it comes to the fine details.  
 
2)  D2 ($499) -  This is a hand-made interconnect that utilizes UP-OCC grade copper and is the purest grade of copper you can source.  It utilizes 2x Neotech 20 gauge UP-OCC cotton-insulated wire for signal and 2x Neotech 20 gauge UP-OCC cotton insulated wire for ground.  It incorporates high-quality WBT 0102 platinum-plated silver RCA plugs.  At its asking price, this cable is a steal and compares very favorably to the much more expensive Audience AU24SX that I listened to recently which lists for $1,850.  For those unfamiliar with what OCC is, it is a casting process developed to defeat annealing issues and virtually eliminates all grain boundaries using a unique patented process.  It yields a single cystal of copper (or silver) up to 125 meters in length resulting in an unimpeded free path for the best possible signal transfer.  UP-OCC (where UP stands for Ultra Pure) provides copper (or silver) with the least possible oxides and other impurities resulting in a purity of up to >99.99998% (6 nines) where standard oxygen free copper usually has a purity of only >99.99% (4 nines).  How does it compare against the Blue Jeans IC?  It shares a similar rich and pleasing tonality but is immediately smoother and considerably better resolved.  Using the same 20-second segment of Mahler's 7th (16/44) and Almost Blue by Diana Krall (16/44), there is more air around the instruments and around Diana's voice.  Consequently, details are more easily discerned.  It's almost as if I went from 320k MP3 to lossless 16/44.   
 
3)  Duelund Silver IC ($425) - This is a unique presentation of silver in a cable developed by the late Danish legend, Steen Duelund, where a thin round silver wire is wrapped in cotton and impregnated in oil. It is said to result in a smooth silky sound with copper-like warmth yet with the resolution of silver.  I found this to be an apt description with a warm tonality somewhere between the Blue Jeans and the UP-OCC Copper IC but more resolving than either.  For those looking to tame a bright system but not wishing to compromise too much on resolution, this one is a good choice.  It doesn't have the rich full body of the Blue Jeans but it has beguiling speed and finesse.  Those wishing for a "vinyl-like" sound will probably feel most at home with this cable.  
 
4)  D3 ($549) - This cable incorporates an alloy comprised of both silver and gold but unlike other alloys that incorporate this mixture, this Neotech product is made using the OCC method.  It is said to have the positive attributes of silver in terms of speed and resolution  but where silver can sometimes be criticized for sounding lean and bland, the gold is supposed to add more body and more accurate tone.  To my ears, this cable easily out-resolved the previous cables.  The presentation was more forward, especially compared against the Duelund Silver cable.  The speed and dynamics with this cable is just amazingly good.  The tonality is not as thick compared against the Blue Jeans but is more accurate.  The timbre of the piano on the Krall track is definitely more spot on.  My engagement with Mahler is now considerably raised.  All the players are much much better discerned and the depth of detail is unmistakably better compared to the previous cables.  
 
5)  D4 ($1175) - This is Dave Cahoon's best cable.  While it also incorporates an alloy that combines both silver and gold using the OCC method, he commissioned Neotech to create a proprietary mixture of silver and gold for him that is not available to the public.  He refuses to divulge what this mixture is and considers it his intellectual property.  Signal wire is comprised of 4x28 guage wire per cable in a cotton dielectric.  Unlike the D3 which utilizes 18 gauge UP-OCC copper wire for ground, the D4 utilizes 6x26 gauge UP-OCC silver wire for ground.  How does it sound?  LIke the D3 but discernably better.  The gap is not as large as the D3 vs the cables before it but there is a definite upgrade in resolution.  Tone is fuller and more saturated suggesting a greater gold content.  I wouldn't call this cable warm like the copper wires nor would I call it cool or sterile.  While it has more body than the D3, it does not sound as if it comes at the compromise of speed.  If anything, there appears to be more transparency and more resolution.  Compared against the Spore4 by itself (which is made of UP-OCC silver with no gold), there is a definite increase in tonal body and richness with the D4 and perhaps the timbre is more accurate whereas the Spore4 by itself presents a more airy treble and fleetness of foot.  The Spore4 layers a bit better but the D4 has a more organic flow.  If you are a fan of DHC, as I am, you know that Peter Bradstock is not a believer in silver/gold alloy wire and in fact, he makes fun of it on his website.  Having now heard it and directly compared it, there is a real argument for this mixture.  In the end, it comes down to personal preference but I actually very much prefer the combination of D4 > HFC magnetic device > Silver Spore4 over the Silver Spore4 by itself.  
 
6)  HFC CT-1E ($2800) - Those of you who have followed my posts know that I have a bias for HFC cables and I will readily admit it.  I just like what this magnetic technology does and nothing I have heard has come close to matching it.  I actually own a higher end CT-1UR interconnect that retails for $8900 (that I was able to find used at a considerable bargain) that blows this one away but I went with the lower end CT-1E so that the comparison would be on a more even footing.  How does it compare?  Trying to be objective, it is easily the most resolving of all of the cables and very easily discerned on blind testing.  The level of clarity is just at another level.  The timbre of the piano in the Krall track is the most convincing yet.  The decay is the most natural where it lingers when it is supposed to linger and rapidly dissipates when there shouldn't be any overhang.  The treble has a sparkle to it but yet it isn't bright and never harsh.  As for the Mahler track, the players are solidly in position on the soundstage and you have a much more confident sense of what instruments are playing.  The speed of this cable is just amazing.  
 
This comparison has led me to be curious about other very expensive cables like the Transparent Magnus Opus, the cable of choice for many dCS and MSB owners.  The top end Magnus Opus RCA interconnects can sell for up to $35k a pair.  Having spoken to a Transparent dealer at length, it was interesting to find that as you go up the chain from Reference to the XL to the Opus and then the Magnum Opus, the main difference has more to do with improved mechanical resonance control and build quality.  With the top end Magnus Opus, the cables are custom built and tuned to match the electronic and physical details of the components used and the listening environment.  Transparent even comes to your home and performs the termination soldering on site.  According to the dealer, as you go up the chain from the Gen 5 Ultra to Magnus Opus, the tonality doesn't change although control, low-frequency articulation and depth improves.  Of interest, Transparent prefers the tonality of copper and made a conscious choice to avoid silver in any of their cables.
 
Having directly compared the resolving ability of the purest form of copper vs silver, to my ears, it's no contest.  Which tonality you prefer is a matter of personal preference but when it comes to resolution, silver easily wins.  What is enlightening about this comparison is that the DAVE revealed the differences so easily, something that I doubt I could have so easily discerned with my previous systems.  Here is proof.  As I often do, especially when I'm not sure I can really hear a difference, I resort to blind testing.  In this exercise, this was easy to perform and my wife was able to swap cables within a matter of 30 seconds.  When I typically blind test different components, I usually do an A/B comparison.  When I feel the differences are quite obvious, I might even do an A/B/C comparison but never before have I done an A/B/C/D/E/F/G comparison.  That's right, instead of comparing only 2 cables against each other at a time, I blindly compared all 6 cables against each other at the same time.  My wife started with one cable of her choosing and I wrote down certain characteristics after listening to 20-second snippets of 2 different tracks.  Beside these snippets, I would jot down which cable I thought I was listening to.  She would then move on to the next cable and the next until I heard all 6 cables.  There were a couple of instances when I thought I was listening to a certain cable only to change my mind after hearing the next cable and I allowed myself this prerogative.  At the end, I scored 100%.  While some would suggest I have some magical golden ear, I would suggest that I'm not that good.  The better explanation is that the DAVE is that good, that it could differentiate the characteristics of different cables this well.  With the Blue Jeans Cable, would I be able to differentiate the DAVE against the Mojo?  I highly doubt it.  Could I do it with the HFC CT-1E or even the Zenwave D4, I'm pretty sure I could and I suspect you could, too.  With the DAVE, do cables matter?  Absolutely.

 
Great review Roy!
 
And the winner is ?

 

[EVOLVIST]

   
Great review Roy!
 
And the winner is ?

 

 

[pkcpga]

As many that follow this thread know, there have been comments made recently about how little difference certain people found with the DAVE compared to another DAC.  This has led me to wonder if this is because expectations were unrealistic or because a person's system wasn't resolving enough?  You could also consider the possibility that a certain person doesn't have a discerning enough ear but I'm less inclined to believe this as even my non-audiophile wife can easily discern between the DAVE and any other DAC I have had in my home for testing.

As someone recently reminded me, I had posted once that what is connected after the DAVE can make a bigger difference than what is connected before the DAVE and I continue to believe that this is true.  While the DAVE is the most resolving source I have ever experienced, speakers and headphones still make a bigger difference.  While there are some who can't readily appreciate the differences between DACs, I don't believe anyone would have trouble differentiating between the HD800, HE-1000, LCD-3 or Abyss in a blind test.  

But what about cables?  For some, this remains an overlooked or underestimated component.  Having looked at the component list of a recent poster who claimed he couldn't tell much difference between the DAVE and another DAC, I was surprised to see he had very expensive and well-regarded speakers and monoblock amplifiers but was using a pair of 20-year old interconnects of uncertain reputation.  I suspect my wanting to discuss the impact of cables will cause some to dismiss this post.  I, too, belonged to this group once.  In fact, before the DAVE, I struggled to hear much difference among cables.  As I previously mentioned, however, because the DAVE is so revealing, the differences among cables are more easily discerned with the DAVE.  Looking at it another way, if you are going to maximize the potential of your DAVE, cables absolutely matter...at least that is the premise I would like to now prove.

Well, I decided to look at the impact of interconnects with the DAVE more formally to see just how much they matter and how they might affect the resolution of a transducer like the HE-1000 or Abyss when connected to the DAVE.  If you are to believe the Blue Jeans Cables website (makers of no-nonsense budget cables), they believe that "The most important attributes of a line-level unbalanced audio cable are (1) shielding, and (2) capacitance."  And that's it.  At a fundamental level, this is probably true although they seem to believe that the measures they undertook to achieve "an extremely low capacitance of 12.2 pF/ft" made for an adequately competent interconnect.  Indeed, I bought into this idea and for years, I used Blue Jeans Cables RCA interconnects.  

As I made upgrades to my system, it only made sense to also explore upgarding my cables and periodically, I did so.  I tried a variety of interconnects, both single-ended and balanced, from manufacturers like Cardas, AudioQuest, Audience, Morrow and JPS Labs before settling on a set of Antipodes Reference RCA ICs when I bought my TotalDac.  While I could hear differences, especially between the inexpensive Blue Jeans ICs and the Antipodes, the differences somehow were nothing to write home about and it seemed to be more about tonal differences than resolution differences.

For this set of tests, I brought out my old pair of Blue Jeans Cables RCA interconnects ($30) as a baseline comparator.  I decided to specifically look at the impact of metallurgy with respect to resolution, specifically copper vs silver vs silver/gold alloy.  I also wanted to assess the impact of standard (unspecified) purity vs UP-OCC (Ultra Pure-Ohno Continuous Cast) as well as the impact of different dielectrics (teflon vs cotton) and so I borrowed several sets of interconnects from Dave Cahoon, owner of Zenwave Audio.  Thrown into the mix was a pair of HFC CT-1E interconnects.  All were 1 meter in length except for the Blue Jeans IC which was 0.5 meters.




Here is my methodology:

As some of you are aware, I have been testing a prototype headphone device by High Fidelity Cables that magnetizes the analog headphone signal before it is sent to my headphone via my Spore4 headphone cable.  For those not aware of what this looks like, here it is sitting to the right of my DAVE:




This is a passive device with the both RCA and 6.35mm inputs on the back:




This has proven to be a helpful device in this comparison of various interconnects.  Here is what the setup looks like connected to various interconnects:




 
With the DAVE, do cables matter?  Absolutely.

I completely agree the Dave is very transparent and I immediately noticed the difference with nordost cables and decided to switch all my cabling to nordost from speaker wires to interconnects. I might have spent the cost of the Dave all over again but there's definitely a very noticable difference, not as great as switching to the Dave but still worth it for myself.

 

[rgs9200m]

For interconnects, Stealth Indras and Sakras are excellent from my experiments. The bass is extremely clear, and the upper highs are filled out to remove hardness but leave a great silky shimmer.
There is a sense of calmness and authority that is unique. It just relaxes things but leaves everything sound intact. I didn't even think cables could do this.
 
Also, any kind of intermediate thingy, even an adapter can really mess up a cable I have found. Only a direct connection will do.
I did a lot of A/B testing years ago with top cables from big names like Nordost, Kimber, Audioquest, Transparent and more, and the Stealth was just plain special. 
 
Expensive, but an interconnect for life. (I joke that, when you get old, you can use them for a retirement fund.) If you have not heard these in your own system, you do not know what you are missing.
If you can afford a Dave and high-end phones, perhaps you could set aside some funds for these.
 
Way back in 2005, I used to converse with a fellow who was a doctor who had a really expensive system (speaker based), and  I would email back and forth with him frequently and one day I mentioned I liked 
this or that particular interconnect and he said just stop, stop. Get a Stealth Indra. This is it. 
So I took his suggestion, tried one, and I was a believer. I never went back, except to try a Sakra, which can be even better, more calmness for any sense of digital brightness.
 
They show up used regularly (not here much, usually on the speaker-based audiophile sites), so there are some deals on them.

 

[x RELIC x]

The iFi power supply does not suck. It is a perfectly acceptable entry point to the microRendu world - that has given me the best input so far into my DAVE.

It is no surprise that bigger power supplies (that cost multiple times more than the iFi) will give further improvements. But, at less cost than a typical audiophile fuse, the iFi will give a fair taste of better things to come.
Of course, there are many variables with the incoming mains quality that could give different results for different people.

In theory, the upcoming LPS-1 should be largely independent of the upstream power supply. So in theory, the iFi may end up being effectively as good as a mega bucks power supply - in terms of feeding the LPS-1. I suspect it won't be quite as simple as that, because nothing is perfect, but nothing is proven yet.  

Until that point, the iFi is a reasonable low cost way of waiting for the LPS-1 situation to pan out

Perhaps I could have worded my post differently. Essentially that 'review' of the uRendu basically only showed measurements that indicated the iFi iPower produced the most noise with the uRendu in the measurements. Everything else was a wash, so it's not really a 'review' of the uRendu, and therefore my comment about the validity of the 'review'. I haven't heard the iPower so I really have no comment on it specifically.

 

[Christer]

Spoiler: Quoted post

  As many that follow this thread know, there have been comments made recently about how little difference certain people found with the DAVE compared to another DAC.  This has led me to wonder if this is because expectations were unrealistic or because a person's system wasn't resolving enough?  You could also consider the possibility that a certain person doesn't have a discerning enough ear but I'm less inclined to believe this as even my non-audiophile wife can easily discern between the DAVE and any other DAC I have had in my home for testing.
 
As someone recently reminded me, I had posted once that what is connected after the DAVE can make a bigger difference than what is connected before the DAVE and I continue to believe that this is true.  While the DAVE is the most resolving source I have ever experienced, speakers and headphones still make a bigger difference.  While there are some who can't readily appreciate the differences between DACs, I don't believe anyone would have trouble differentiating between the HD800, HE-1000, LCD-3 or Abyss in a blind test.  
 
But what about cables?  For some, this remains an overlooked or underestimated component.  Having looked at the component list of a recent poster who claimed he couldn't tell much difference between the DAVE and another DAC, I was surprised to see he had very expensive and well-regarded speakers and monoblock amplifiers but was using a pair of 20-year old interconnects of uncertain reputation.  I suspect my wanting to discuss the impact of cables will cause some to dismiss this post.  I, too, belonged to this group once.  In fact, before the DAVE, I struggled to hear much difference among cables.  As I previously mentioned, however, because the DAVE is so revealing, the differences among cables are more easily discerned with the DAVE.  Looking at it another way, if you are going to maximize the potential of your DAVE, cables absolutely matter...at least that is the premise I would like to now prove.
 
Well, I decided to look at the impact of interconnects with the DAVE more formally to see just how much they matter and how they might affect the resolution of a transducer like the HE-1000 or Abyss when connected to the DAVE.  If you are to believe the Blue Jeans Cables website (makers of no-nonsense budget cables), they believe that "The most important attributes of a line-level unbalanced audio cable are (1) shielding, and (2) capacitance."  And that's it.  At a fundamental level, this is probably true although they seem to believe that the measures they undertook to achieve "an extremely low capacitance of 12.2 pF/ft" made for an adequately competent interconnect.  Indeed, I bought into this idea and for years, I used Blue Jeans Cables RCA interconnects.  
 
As I made upgrades to my system, it only made sense to also explore upgarding my cables and periodically, I did so.  I tried a variety of interconnects, both single-ended and balanced, from manufacturers like Cardas, AudioQuest, Audience, Morrow and JPS Labs before settling on a set of Antipodes Reference RCA ICs when I bought my TotalDac.  While I could hear differences, especially between the inexpensive Blue Jeans ICs and the Antipodes, the differences somehow were nothing to write home about and it seemed to be more about tonal differences than resolution differences.
 
For this set of tests, I brought out my old pair of Blue Jeans Cables RCA interconnects ($30) as a baseline comparator.  I decided to specifically look at the impact of metallurgy with respect to resolution, specifically copper vs silver vs silver/gold alloy.  I also wanted to assess the impact of standard (unspecified) purity vs UP-OCC (Ultra Pure-Ohno Continuous Cast) as well as the impact of different dielectrics (teflon vs cotton) and so I borrowed several sets of interconnects from Dave Cahoon, owner of Zenwave Audio.  Thrown into the mix was a pair of HFC CT-1E interconnects.  All were 1 meter in length except for the Blue Jeans IC which was 0.5 meters.
 

 
Here is my methodology:
 
As some of you are aware, I have been testing a prototype headphone device by High Fidelity Cables that magnetizes the analog headphone signal before it is sent to my headphone via my Spore4 headphone cable.  For those not aware of what this looks like, here it is sitting to the right of my DAVE:
 

 
This is a passive device with the both RCA and 6.35mm inputs on the back:
 

 
This has proven to be a helpful device in this comparison of various interconnects.  Here is what the setup looks like connected to various interconnects:
 


 
Obviously, both my DHC Spore4 headphone cable and this HFC magnetic headphone device will have some impact on SQ although they were kept constant in the chain.  The only variable was the interconnect.
 
The interconnects used were as follows and my findings are included as well:
 
1)  Blue Jeans Cables RCA LC-1 interconnect ($30)  -  Unlike the other copper cables, these cables utilize an unspecified purity of copper but at this low price, it is undoubtedly not UP-OCC grade.  It utilizes a foamed polyetheylene dielectric designed for high flexibility and easy routing.  It produces a nice rich, thick tone -- beautiful, in fact.  Upon first listen and paired with the HFC headphone device + Spore4 headphone cable, it sounded very pleasing.  Easily a bargain at $30 and in the absence of any comparison, I could be lulled into thinking this is a very acceptable sound.  Once compared to any of the other cables, however, it became evident how slow and syrupy this cable is and how this cable keeps secrets.  This cable paints the broad strokes well but will leave you wanting when it comes to the fine details.  
 
2)  D2 ($499) -  This is a hand-made interconnect that utilizes UP-OCC grade copper and is the purest grade of copper you can source.  It utilizes 2x Neotech 20 gauge UP-OCC cotton-insulated wire for signal and 2x Neotech 20 gauge UP-OCC cotton insulated wire for ground.  It incorporates high-quality WBT 0102 platinum-plated silver RCA plugs.  At its asking price, this cable is a steal and compares very favorably to the much more expensive Audience AU24SX that I listened to recently which lists for $1,850.  For those unfamiliar with what OCC is, it is a casting process developed to defeat annealing issues and virtually eliminates all grain boundaries using a unique patented process.  It yields a single cystal of copper (or silver) up to 125 meters in length resulting in an unimpeded free path for the best possible signal transfer.  UP-OCC (where UP stands for Ultra Pure) provides copper (or silver) with the least possible oxides and other impurities resulting in a purity of up to >99.99998% (6 nines) where standard oxygen free copper usually has a purity of only >99.99% (4 nines).  How does it compare against the Blue Jeans IC?  It shares a similar rich and pleasing tonality but is immediately smoother and considerably better resolved.  Using the same 20-second segment of Mahler's 7th (16/44) and Almost Blue by Diana Krall (16/44), there is more air around the instruments and around Diana's voice.  Consequently, details are more easily discerned.  It's almost as if I went from 320k MP3 to lossless 16/44.   
 
3)  Duelund Silver IC ($425) - This is a unique presentation of silver in a cable developed by the late Danish legend, Steen Duelund, where a thin round silver wire is wrapped in cotton and impregnated in oil. It is said to result in a smooth silky sound with copper-like warmth yet with the resolution of silver.  I found this to be an apt description with a warm tonality somewhere between the Blue Jeans and the UP-OCC Copper IC but more resolving than either.  For those looking to tame a bright system but not wishing to compromise too much on resolution, this one is a good choice.  It doesn't have the rich full body of the Blue Jeans but it has beguiling speed and finesse.  Those wishing for a "vinyl-like" sound will probably feel most at home with this cable.  
 
4)  D3 ($549) - This cable incorporates an alloy comprised of both silver and gold but unlike other alloys that incorporate this mixture, this Neotech product is made using the OCC method.  It is said to have the positive attributes of silver in terms of speed and resolution  but where silver can sometimes be criticized for sounding lean and bland, the gold is supposed to add more body and more accurate tone.  To my ears, this cable easily out-resolved the previous cables.  The presentation was more forward, especially compared against the Duelund Silver cable.  The speed and dynamics with this cable is just amazingly good.  The tonality is not as thick compared against the Blue Jeans but is more accurate.  The timbre of the piano on the Krall track is definitely more spot on.  My engagement with Mahler is now considerably raised.  All the players are much much better discerned and the depth of detail is unmistakably better compared to the previous cables.  
 
5)  D4 ($1175) - This is Dave Cahoon's best cable.  While it also incorporates an alloy that combines both silver and gold using the OCC method, he commissioned Neotech to create a proprietary mixture of silver and gold for him that is not available to the public.  He refuses to divulge what this mixture is and considers it his intellectual property.  Signal wire is comprised of 4x28 guage wire per cable in a cotton dielectric.  Unlike the D3 which utilizes 18 gauge UP-OCC copper wire for ground, the D4 utilizes 6x26 gauge UP-OCC silver wire for ground.  How does it sound?  LIke the D3 but discernably better.  The gap is not as large as the D3 vs the cables before it but there is a definite upgrade in resolution.  Tone is fuller and more saturated suggesting a greater gold content.  I wouldn't call this cable warm like the copper wires nor would I call it cool or sterile.  While it has more body than the D3, it does not sound as if it comes at the compromise of speed.  If anything, there appears to be more transparency and more resolution.  Compared against the Spore4 by itself (which is made of UP-OCC silver with no gold), there is a definite increase in tonal body and richness with the D4 and perhaps the timbre is more accurate whereas the Spore4 by itself presents a more airy treble and fleetness of foot.  The Spore4 layers a bit better but the D4 has a more organic flow.  If you are a fan of DHC, as I am, you know that Peter Bradstock is not a believer in silver/gold alloy wire and in fact, he makes fun of it on his website.  Having now heard it and directly compared it, there is a real argument for this mixture.  In the end, it comes down to personal preference but I actually very much prefer the combination of D4 > HFC magnetic device > Silver Spore4 over the Silver Spore4 by itself.  
 
6)  HFC CT-1E ($2800) - Those of you who have followed my posts know that I have a bias for HFC cables and I will readily admit it.  I just like what this magnetic technology does and nothing I have heard has come close to matching it.  I actually own a higher end CT-1UR interconnect that retails for $8900 (that I was able to find used at a considerable bargain) that blows this one away but I went with the lower end CT-1E so that the comparison would be on a more even footing.  How does it compare?  Trying to be objective, it is easily the most resolving of all of the cables and very easily discerned on blind testing.  The level of clarity is just at another level.  The timbre of the piano in the Krall track is the most convincing yet.  The decay is the most natural where it lingers when it is supposed to linger and rapidly dissipates when there shouldn't be any overhang.  The treble has a sparkle to it but yet it isn't bright and never harsh.  As for the Mahler track, the players are solidly in position on the soundstage and you have a much more confident sense of what instruments are playing.  The speed of this cable is just amazing.  
 
This comparison has led me to be curious about other very expensive cables like the Transparent Magnus Opus, the cable of choice for many dCS and MSB owners.  The top end Magnus Opus RCA interconnects can sell for up to $35k a pair.  Having spoken to a Transparent dealer at length, it was interesting to find that as you go up the chain from Reference to the XL to the Opus and then the Magnum Opus, the main difference has more to do with improved mechanical resonance control and build quality.  With the top end Magnus Opus, the cables are custom built and tuned to match the electronic and physical details of the components used and the listening environment.  Transparent even comes to your home and performs the termination soldering on site.  According to the dealer, as you go up the chain from the Gen 5 Ultra to Magnus Opus, the tonality doesn't change although control, low-frequency articulation and depth improves.  Of interest, Transparent prefers the tonality of copper and made a conscious choice to avoid silver in any of their cables.
 
Having directly compared the resolving ability of the purest form of copper vs silver, to my ears, it's no contest.  Which tonality you prefer is a matter of personal preference but when it comes to resolution, silver easily wins.  What is enlightening about this comparison is that the DAVE revealed the differences so easily, something that I doubt I could have so easily discerned with my previous systems.  Here is proof.  As I often do, especially when I'm not sure I can really hear a difference, I resort to blind testing.  In this exercise, this was easy to perform and my wife was able to swap cables within a matter of 30 seconds.  When I typically blind test different components, I usually do an A/B comparison.  When I feel the differences are quite obvious, I might even do an A/B/C comparison but never before have I done an A/B/C/D/E/F/G comparison.  That's right, instead of comparing only 2 cables against each other at a time, I blindly compared all 6 cables against each other at the same time.  My wife started with one cable of her choosing and I wrote down certain characteristics after listening to 20-second snippets of 2 different tracks.  Beside these snippets, I would jot down which cable I thought I was listening to.  She would then move on to the next cable and the next until I heard all 6 cables.  There were a couple of instances when I thought I was listening to a certain cable only to change my mind after hearing the next cable and I allowed myself this prerogative.  At the end, I scored 100%.  While some would suggest I have some magical golden ear, I would suggest that I'm not that good.  The better explanation is that the DAVE is that good, that it could differentiate the characteristics of different cables this well.  With the Blue Jeans Cable, would I be able to differentiate the DAVE against the Mojo?  I highly doubt it.  Could I do it with the HFC CT-1E or even the Zenwave D4, I'm pretty sure I could and I suspect you could, too.  With the DAVE, do cables matter?  Absolutely.

Have you tried any Chord rca cables with DAVE?
One might assume that Chord cables would work well with chord dacs?
I use Chord Indigo Blue and  Audioquest Columbia  which I use with my Hugo or my  Benchmark .
I am not sure the Audioquest are actually the columbia but they have a little battery box that maybe is supposed to do a similar job as some of the stuff you have mentioned ,ie electromagnetic ,isolation conduction or whatever.
Anyway they sound very different indeed.
With some recordings I prefer one over the other.
It varies very much depending on DAC/recording used which cable  I connect.
and also whether I connect directly to poweramp or via pre or not. I can make any recording sound at least 8 different ways both via headphones and speakers.
The DAC is just one  of several spicings and variables in any system.
What does your magic box  add to the equation compared to connecting your headphones directly to the DAVE ?
Is it available on the market?
Personally I would recommend people interested in the highest possible transparency via both speakers and headphones to audition  electrostatic headphones and speakers.
They are imho the most transparent least colored on the market.
I have yet to hear  traditional box speakers that are as open and free of distortions and deliver such a believable coherent soundstage as electrostatic speakers.