Garth’s new AQ Mythical Creatures Interconnects

[BKDad]

The Atma-Sphere preamp output impedance isn't that low - spec'd at 250 Ohms.  Per the website.

Their very top of the line power amplifiers offer the option to set the balanced input impedance to 600 Ohms.  In that case, the cable is approximately terminated in its characteristic impedance at both ends.  More or less.  Maybe that matters for short cables, maybe not.  Along the same lines, their power amplifiers have a relatively high output impedance for an audio power amplifier, not all that different from a loudspeaker's input impedance.   That might present some other challenges in some cases.  Engineering is full of compromises...

If you look at the Ralph's patent portfolio, it's evident that he takes noise immunity very seriously.  One of his patents is a technique to reduce common mode current coupling through the power transformers.  It's completely consistent that he follows the guidelines of AES48.

So, I think that a big part of his success is using well established engineering approaches to minimize the effects of common mode noise currents.  Whether it's the use of truly balanced circuitry or proper cable connections between components, he makes a really sincere effort to rid his systems of common mode noise issues.  Good on him!  It's an issue that most often gets ignored or glossed over in the home audio world.  His approach isn't the only solution to the problem, but it seems to work for him.  (BTW, I don't know the man.  I'm not sure I've ever even been in the same room as a piece of Atma-Sphere equipment.  I only know what I am able to read.)

Connecting a system up with pieces spread around the room, plugged into various AC outlets, and on and on is not the same as connecting a single piece of gear into an Audio Precision test set where the AP has been optimized to minimize common mode currents, present optimal impedances to the gear under test, and much more.  Minimizing the Heisenberg effects of the test gear also covers up some real world application issues - nobody actually listens to an amplifier connected to an Audio Precision test set.  No knock on AP; they do exactly what they claim to do.  It's the users you have to question.

One other note...  His amplifier circuits at a fundamental level are similar to what Mr. Vandersteen describes his amplifier concepts to be.  Obviously, the details and the implementations are very different, but the underlying concepts are similar.  

[Holmz]

9 hours ago, BKDad said:

…

One other note...  His amplifier circuits at a fundamental level are similar to what Mr. Vandersteen describes his amplifier concepts to be.  Obviously, the details and the implementations are very different, but the underlying concepts are similar.  

Maybe it was a spatial thing?
Didn’t Dean come out of the twin cities, and ARC, Atmasphere, TriPlanner… are are within a drive away.
It seems like there was some critical mass of audio happening there?

[ctsooner]

It's also ok to mention other speaker manufactures.  Maggies are also up there and work with ARC and have for years I believe (correct me if I'm wrong please).  It's an amazing city for high end audio.  

I was impressed by Atmosphere when I heard it. I can only remember hearing it once and I forget where and with what, but remember liking what I was hearing.  I trust Bob's ears and I know he really likes their gear.  I do hope to hear his new amp someday as I'd love for Class D to be able to make great sound.  Like anything else, it still comes down to compatibility with the other components.  To me the major question is how it sounds and then if I'm using with Vandy speakers, will it mess up the time and phase correct part of the equation.  

Not everyone even hears the difference adn it's why many hear Vandy's in the same way they hear a Wilson (or any other speaker).  I've noticed that all audiophiles seem to lock into one particular part of the presentation and buy a speaker that does that part great.  Most Vandy owners I know are into the music as much as the gear.  We all seem to like Richard's trade offs.  I also notice that most purchase gear that uses similar trade offs, which I guess makes sense.  

To hear that Atmosphere's products on a fundamental level are similar to Vandersteen products, makes a ton of sense and it's why a few of you guys swear by their products which is cool.

 

[GdnrBob]

See what a nice group we have here?

It seems so hard to find other forums where people respect the opinions of others. -I have pretty much given up on Audiogon.

 

In any case, the Atma Class D's need to be run in before I set up a trial at Audioconnection. Johnny seems OK with it, so we just have to make a day that is good for everyone. Probably sometime in December or January.

PM me if you are interested in joining.

Bob

[Holmz]

1 hour ago, GdnrBob said:

It seems so hard to find other forums where people respect the opinions of others. -I have pretty much given up on Audiogon.

It can be hard to respect other’s opinions when those opinions include things like the speed of sound is different for different frequencies/pitch.

I put in a dog door for the puppy. We had to use treats and push her through it a few times, and she was not a happy pup.
That was 2 days ago, I want out with her this morning and as soon as her paws hit the rain soaked pavement she was in that dog door like a flash.
And when we are outside and the pup is inside, she is through the door in a flash.

I picked up a bag from the tool shop, as the pink one did not really match my outfit, and use that to sneak her around if I need to quickly duck into a shop.

 

anyhow… when it is raining I do not really like to be outside in either.
So the debates and opinions on AG are my version of the dog door, to avoid doing something constructive out in the cold.
Or when the pup does not want to be in the bag
 

[BKDad]

2 hours ago, Holmz said:

It can be hard to respect other’s opinions when those opinions include things like the speed of sound is different for different frequencies/pitch.

Actually…

The speed of sound is constant only under conditions that follow the ideal gas law.  Ordinary air in a room has varying densities due to humidity, temperature gradients, and so on.  These affect the speed based on the wavelength and the size of the discontinuities.   

This is yet another example where the first order engineering approximations are more than adequate for most purposes, like home audio reproduction, until they aren’t.  But, there’s so many other non-ideal aspects of listening rooms that this gets lost in the, ahh, noise.  (Try playing a sweep tone through your stereo and listen to all the various articles in the room vibrate at various frequencies.)

[BKDad]

Supplementary link for the above:  https://pages.mtu.edu/~suits/SpeedofSound.html

(The rest of that web site is pretty fun reading, too.)

[Holmz]

1 hour ago, BKDad said:

Actually…

The speed of sound is constant only under conditions that follow the ideal gas law.  Ordinary air in a room has varying densities due to humidity, temperature gradients, and so on.  These affect the speed based on the wavelength and the size of the discontinuities.   

This is yet another example where the first order engineering approximations are more than adequate for most purposes, like home audio reproduction, until they aren’t.  But, there’s so many other non-ideal aspects of listening rooms that this gets lost in the, ahh, noise.  (Try playing a sweep tone through your stereo and listen to all the various articles in the room vibrate at various frequencies.)

^yeah - understand and agree^ - and likewise the EU6 emissions need humidity sensors in addition to pressure and temp.
O2 and N2 are pretty close to ideal, and make up a lot of the air.

But that is as saying goes…
“Confucius say, Man who peel onion, he get watery eye.”

The context seemed like it was describing a linear deal where “v is proportional to f”, and not wavelength is proportional to f, where v is  assumed to be largely constant.

 

Quote

... The highest sound we can hear is a sine wave about an inch long and the deepest sound we can hear is a wave 25ft long, they travel at very different speed so the higher sounds need to be delayed and the lowest played first. …

I think the fellow was talking about bigger shifts that tilting a Vandy with a laser pointer to get it all down to the mm?

 

Anyhow… back to a story about what makes up the air:

A friend ours was a prison guard. He has a stack of LPs, but his system is on bit different level than most here.
We always have a good time and we enjoy his and his wife’s company, and always the food and wine.
He also likes bicycles and cars, so we overlap.

He was telling about being in the court house with a prisoner who was testifying… I need to add his phonetic local accent.

Quote

Prosecutor: Can you tell us what happened?
Witness: Dis bloke just come up and hit me.
Prosecutor: What happened then?
Witness: Wez on the ground ground fighting and he stab me. (Pointing a crocked finger towards the defendant.)
Prosecutor: How do you know he stabbed you?
Witness: I could feel the hair on me back, right here (Lifting up his shirt and pointing to the scar his unfurry back.)
Prosecutor: The hair on your back? What do you mean you could feel it?
Witness: I could feel the hair just going in and out of me when I try and breathe.
Prosecutor: What hair?
Witness: You know… “the hair”… the hair that you breathe.

Our friend said he had to look at his shoes, for a while, and most of the others did the same.
It was not exactly like Confucius, but his eyes were watering.

 

His other stories are even better, but the language is unfortunately, a bit beyond the rules of the forum and polite company in general.
His hand gestures, and story telling style help. 

Edited October 24, 2022 by Holmz

[Delkat]

Back to the original topic; I read one of Garth’s white papers related to this mythical creatures.  I’m an electrical engineer by background and it seemed a bit like mumbo jumbo. I’m not sure what they were shooting for by publishing that but it didn’t make a lot of sense from a technical standpoint. I see 3 possibilities: don’t give away trade secrets, keep it simple for the layman or there’s not a lot of real science behind it. 

[BKDad]

4 minutes ago, Delkat said:

Back to the original topic; I read one of Garth’s white papers related to this mythical creatures.  I’m an electrical engineer by background and it seemed a bit like mumbo jumbo. I’m not sure what they were shooting for by publishing that but it didn’t make a lot of sense from a technical standpoint. I see 3 possibilities: don’t give away trade secrets, keep it simple for the layman or there’s not a lot of real science behind it. 

I'm a bit lost as well.  I can't rationalize at all the "zero impedance" concept.  That would prevent propagation of AC signal down the cable, which doesn't seem like what we all want.

But, AQ clearly knows how to address their market.

There's a sorta review here:  https://www.hifinews.com/content/audioquest-thunderbird-interconnect-cables  If nothing else, it shows pictorially what the cable construction is with some verbal description, too.

If you figure it out, please let us know.  OK - please let me know.  I'm fine with being publicly ridiculed for my ignorance if that's what it takes to get an explanation.

OT, a little...  The explanations I've read about why power cables make a difference in audio system sound quality make no sense either.  I'm not saying that power cables don't matter and they can't possibly affect the reproduced sound characteristics (my experience says quite the opposite), but the explanations make no logical sense, even if you ignore the physics and EE101 aspects.

The real science behind the power cables and the interconnect cable thing you mention isn't nearly as simple to explain and doesn't sound as sexy.  Besides, it kinda goes against the dogma that's been published for years in the audio press and in much marketing material.  That's always a challenge to overcome - the kind of thing that causes fist fights in bars.  But, as you almost certainly know, engineers who have developed and used instrumentation and other related systems have had to contend with these issues for almost a century and have come up with some pretty good solutions and explanations for it all.  Papers and books galore.

[atmasphere]

On 10/19/2022 at 5:42 PM, ctsooner said:

Not sure what to tell you, but go listen.  It's all about system matching and listening and that's the only way you will be able to tell.  I will say that when I first used the WEL's my system was taken to a better place.  They certainly made a nice difference.  The new cables are special for sure.  I'm selling the WEL and Fire to help pay for the new XLR's as it's worth it for me.  YMMV.

 

On 10/20/2022 at 5:22 PM, GdnrBob said:

I don't doubt your observations, but only wanted to input my experience with XLR cable. Like I said, these were far down the AQ line up, so they might have not been as 'revealing'. But, it does seem to agree with Ralph Karsten's opinion that XLR cables are less prone to introducing cable 'artifacts' (when used with equipment using the  AES standard), especially when compared to RCA.

Bob

 

On 10/20/2022 at 7:31 PM, Holmz said:

It would be interesting to know what the output impedance is of Ralph’s preamps is.

Maybe the balanced preamps have a lower output impedance, which would also make the cable less of a deal.

They aren't that low, being zero feedback tube circuits. IME, the output impedance has to be sort of low but it doesn't need to be near zero when driving line level signals- other things become more important.

On 10/21/2022 at 8:56 AM, BKDad said:

Doesn't that suggest, for all you technical type guys, that there's loads of undesired common mode currents running about most home audio systems?  

These days, this can be measured with relatively inexpensive test gear (maybe a few hundred bucks - far less money than these cables) along with a bit of savvy.  Yet, when the results are posted on forums where people proudly label themselves as "objectivists", the effect is roundly denied and the poster gets beaten up.  

This is one of the reasons why I don't find these people to be actually objective and why I have really almost completely stopped posting on the internet.  I much prefer reading about people's personal impressions of why they like or don't the sound of  a component like a loudspeaker, for example.  It may not match my taste and preference, but so what?  At least it's an honest opinion.

Grounding is poorly understood in high end audio. That's understandable; there are engineering tomes on the topic that get really out in the weeds. The balanced line system takes a fairly simple approach to dealing with all of that, which is to simply ignore ground.  As long as the common mode range isn't exceeded, balanced lines can really get you lower noise.

On 10/21/2022 at 6:04 PM, BKDad said:

The AES standard (AES48) is certainly a standard, but it really only describes what wires go to what pins on the interface, especially with regard to chassis and circuit ground.  Beyond that, there's a lot of area subject to interpretation.  People have built large portions of their careers trying to work with this.

There's lots of reasons why balanced cables should be terminated at both ends in the cable's characteristic impedance - roughly 100 Ohms.  There's also a lot of reasons why that is difficult and/or impractical.  Certainly there's not too much in the way of modern equipment that will drive a 200 Ohm load - that'd  mean that you'd need a small power amplifier inside your preamp, phono preamp, or DAC.

If you look at the way things are connected using AES48, the less obvious part is that the signals are not referencing ground. The classic example of this is the output of an audio coupling transformer where the secondary (the output) is very simple. One side is connected to pin 2 (non-inverting) of the XLR and the other side to pin 3 (inverting) of the XLR. Ground (pin 1) isn't connected to the transformer at all. Other than shielding, its ignored. If you look at a tonearm, this how that works- the cartridge connections aren't tied to the tonarm tube in any way, but there is a connection for the tonearm tube, which is the ground wire. Its otherwise entirely ignored (there are no signal currents present in the ground connection- its shielding only).

Its helpful to run things at a lower impedance if you can. This swamps noises picked up by the cable since they usually are induced in an inefficient way, so a lower impedance can swamp them out. In the old days the standard for that impedance was 600 Ohms, this being based on the three wires you can still see on telephone poles, especially near rural train tracks. 600 Ohms is the characteristic impedance (the impedance at which, when terminated by the impedance value, terminates the transmission line so there are no reflections back to the source) of the three wires spaced in open air as they are. This impedance is arbitrary with respect to balanced line interconnects though (which have a CI that is usually much lower) but was used because the low impedance works well to swamp noise. These days the 600 Ohms is no longer used although its common enough to see 1000 or 2000 Ohm inputs, which work about as well.

We built our balanced tube preamps to not only support AES48 but also the 600 Ohm termination value, so they would work with older (usually tube) studio equipment, employing a direct-coupled output we patented.

When you hear differences that seem to make it worth using a particular balanced cable, it almost always is an indication that the cable is being used in a system where some or all of the components are not supporting AES48. For example if ground is referenced, where the circuit for the signal is completed through the ground (shield) then any of the ground loop currents that might be present can intermodulate with those signal currents. You're going to have more noise and the construction of the cable is going to make a difference in the 'sound'.

If you really want to understand the idea behind the balanced line system without knowing anything technical, look at it this way:

In high end audio with single-ended cables the construction of the cable makes an enormous difference and some of those construction techniques can be really expensive.  The balanced line system can be thought of as an exotic cable technology wherein as long as the cable is built correctly, it will not have to be expensive because the equipment driving the cable and receiving it are doing all the heavy lifting. This is fundamentally different from single-ended setups where everything relies on the cable.

[BKDad]

46 minutes ago, atmasphere said:

In high end audio with single-ended cables the construction of the cable makes an enormous difference and some of those construction techniques can be really expensive.  The balanced line system can be thought of as an exotic cable technology wherein as long as the cable is built correctly, it will not have to be expensive because the equipment driving the cable and receiving it are doing all the heavy lifting. This is fundamentally different from single-ended setups where everything relies on the cable.

I'd just add that unbalanced connections can certainly work when you use a truly differential receiver at the downstream end.  More heavy lifting by the equipment.

These issues are even a consideration at much higher frequencies.  Like, say, for example, Ethernet and USB.  HDMI has its issues, too.

Here's some reading for people interested:  http://audiosystemsgroup.com/AES-SCIN-ASGWeb.pdf

[Karlos]

Haha! The retail on 5m run of Dragon XLR is the same as new Kentos.  I think I’ll save money for the Kentos and keep my 5M of AQ Earth XLRs.

[TomicTime]

that to me is true wisdom 🙂 work the transducers !

[ctsooner]

It’s really crazy when in perspective. That’s a long run for many top brands though. I have always liked Earth. Strong at its price point for sure

[nrenter]

Ironically, with that level of spend, you could get a pre-amp and amps that support the AES48 spec and use Mogami XLR / balanced cables.

[GdnrBob]

On 10/29/2022 at 7:30 PM, nrenter said:

Ironically, with that level of spend, you could get a pre-amp and amps that support the AES48 spec and use Mogami XLR / balanced cables.

That Mogami XLR wire is definitely as good as the AQ wire (non-DBS- I can't remember the model name). Johnny Rutan (who's opinion I respect) recommended it, but upon install, I really couldn't hear any significant difference. (Stess: Significant).

Not to beat a dead horse...

But, that trial reinforced the concepts/beliefs of Ralph Karsten- That equipment that supports the AES 48 standard are more immune to cable artifacts.

-Now, if I can just get some time to hook up those Class D amps...😏

Bob