Cable shootout... Are all audio cables the same?

That is a very cool article and test, which sums up my feelings..., posted on June 10, 2014 at 09:07:45
jonbee Audiophile Posts: 1993 Location: Seattle Joined: June 26, 2001	pretty well- yes there are audible differences, but which is "best" is like decided which spices used in cooking are "best"- although some are clearly "better" than some others in certain elements, context and taste are key to getting the best end results, and price is not the biggest element in the equation- matchups rule!

RE: Cable shootout... Are all audio cables the same?, posted on June 10, 2014 at 14:46:58
chervokas Audiophile Posts: 10 Joined: May 21, 2012	Except for maybe the Mogami, which maybe sounds a very tiny bit warmer and more mid-forward, I don't think I could tell one sound clip from another, at least not listening at work off the PC soundcard with some Sony MDR-7506 phones. Maybe higher res listening would reveal more differences, but I dunno. Jason Chervokas

RE: That is a very cool article and test, which sums up my feelings..., posted on June 10, 2014 at 14:04:26
Ubiquitous Biscuit Audiophile Posts: 141 Joined: November 2, 2013	They all sound the same to me

Which direction were the cables in? Nt, posted on June 11, 2014 at 16:07:48
geoffkait	Nt

RE: Cable shootout... Are all audio cables the same?, posted on June 16, 2014 at 11:52:37

robertopisa
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Location: Pisa, Italy
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I did some critical listening today, and I can hear differences from the original file and the other 4 files that were obtained by feeding the original file to the DAC-cable-ADC chain.

Among the 4 cables, I cannot say there is a huge difference. On the other hand, by comparison to the original file, it seems to me that the Gotham is a bit more transparent than the others.

Please note that the cost of the cables is quite different :)

@geoffkait: The cables are XLR terminated, so there is only one direction to use since one connector is male and the other is female.

-R

RE: Cable shootout... Are all audio cables the same?, posted on June 18, 2014 at 18:18:43
geoffkait	You wrote, "@geoffkait: The cables are XLR terminated, so there is only one direction to use since one connector is male and the other is female." Nevertheless, the conductors are still directional, no? Doesn't the manufacturer account for that? Cheers

RE: That is a very cool article and test, which sums up my feelings..., posted on June 21, 2014 at 15:52:12
fstein Audiophile Posts: 2994 Location: fstein Joined: May 18, 2006	Don't say that at the Cable Asylum, they will stone you

RE: Cable shootout.., posted on June 21, 2014 at 19:29:11
tomservo Manufacturer Posts: 8181 Joined: July 4, 2002	Try comparing one file to another and listen to the difference between them which is more dramatic than comparing one to another with the similarities. http://libinst.com/Audio%20DiffMaker.htm If one can hear a difference between the cables, it is well more than large enough to analyze to see that the differences are.

RE: Cable shootout... Are all audio cables the same?, posted on June 21, 2014 at 19:31:13
tomservo Manufacturer Posts: 8181 Joined: July 4, 2002	Ok, i am game, in exactly what way are they directional and how large is that effect an alternating signal like audio?

RE: Cable shootout... Are all audio cables the same?, posted on June 21, 2014 at 20:54:03
geoffkait	The signal is not alternating. Hel-loo!

RE: Cable shootout... Are all audio cables the same?, posted on June 22, 2014 at 06:11:28
tomservo Manufacturer Posts: 8181 Joined: July 4, 2002	So, you pass DC through the cable instead of audio? Fwiw, there are a few signals that are somewhat asymmetric but audio signals alternate direction with a sum that has no DC offset. Perhaps i am not understanding what you mean, describe what you mean as it would appear on an oscilloscope screen, microphone voltage or other metric

RE: Cable shootout... Are all audio cables the same?, posted on June 22, 2014 at 07:54:35
geoffkait	AC refers to alternating current, not alternating signal. There is no alternating voltage either. Thus, when measured a wire or cable will register slightly lower resistance in one direction than the other and more importantly will sound better in one direction than the other.

RE: Cable shootout... Are all audio cables the same?, posted on June 22, 2014 at 16:45:24
tomservo Manufacturer Posts: 8181 Joined: July 4, 2002	Have you ever looked at the output of a phono cartridge, CD player, pre-amp or power amplifier with an oscilloscope? What does one see?

RE: Cable shootout... Are all audio cables the same?, posted on June 22, 2014 at 17:09:00
ahendler Audiophile Posts: 5151 Location: San Antonio, Texas Joined: January 24, 2003	If you do a faurier analysis of an audio signal you find the signal is the combination of a bunch of sine waves which are alternating in polarity. Audio signals produce alternating current in cables Alan

RE: Cable shootout... Are all audio cables the same?, posted on June 22, 2014 at 18:09:51
geoffkait	Sine waves are not alternating current. Nor do audio signals produce alternating current. Hel-loo! The audio signal is the thing that's moving at near light speed down the track.

RE: Cable shootout... Are all audio cables the same?, posted on June 22, 2014 at 18:18:45
tomservo Manufacturer Posts: 8181 Joined: July 4, 2002	Dude Hel-loo, ALL as in 100% of analog audio signals are alternating voltages and if there is a load a the end of the cable opposite the source (which there always is), the current that flows also alternates and both V and I propagate the signal near the speed of light (cable propagation velocity).

RE: Cable shootout... Are all audio cables the same?, posted on June 22, 2014 at 18:27:00
geoffkait	Uh, dude,the whole point is the SIGNAL is not changing directions, the upstream and downstream directions. That is why wire directionality is audible. That is why interconnects and speaker cables are frequently labeled with ARROWS pointing from the source to the amp. Hel-loo! All that other stuff, the electrons, the voltage and the current, you can throw out.

RE: Cable shootout... Are all audio cables the same?, posted on June 23, 2014 at 07:14:56

tomservo
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Dude, you are hopelessly confused with marketing spray.
I will try to explain in non-engineering terms for you.
In 100% of all analogue audio signals, “the signal” IS conveyed by the voltage.

Starting with the microphone, the alternating pressure which IS SOUND is converted to an alternating voltage where there is a precise relationship between the voltage and the pressure (positive and negative) that the microphone experiences. In fact, one can determine the sound pressure IF one has the Voltage at any given instant AND the microphone sensitivity, a Sound level meter simply converts that voltage (rectified) into a meter reading.

Ending with the loudspeaker the Voltage = pressure relationship is preserved and the perfect loudspeaker produces a pressure exactly proportional to the Voltage, independent of frequency , the inverse of the microphone.

In all cases, the signal is an alternating signal that ends up producing sound pressure that is positive and negative relative to ambient air pressure.

RE: Cable shootout... Are all audio cables the same?, posted on June 23, 2014 at 08:07:32
geoffkait	So far I have not heard you say that the audio signal itself, the electromagnetic wave, the one that travels down the cable at near light speed, is alternating back and forth along the cable (as claimed by naysayers of wire directionality). You've been dancing all around it, So, whaddya think, is the audio signal traveling down the cable in one direction only?

RE: Cable shootout... Are all audio cables the same?, posted on June 23, 2014 at 08:45:23

tomservo
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“So far I have not heard you say that the audio signal itself, the electromagnetic wave, the one that travels down the cable at near light speed, is alternating back and forth along the cable (as claimed by naysayers of wire directionality)”

Well that is true, I have not said that.
Perhaps I can clarify this further but it will involve some electronic engineering.

It is current alone that produces the H or magnetic induction resulting in a magnetic field B, it is Voltage across a load or resistance which causes current to flow.

The signal Voltage propagates at the cables propagation velocity and is set by the cables series inductance and parallel capacitance and can vary from near light speed to as slow as near half light speed.

It sounds like your confusion is based on the “signal” being somehow different than the Voltage which is the signal.

If interested, the next edition of “Handbook for Sound Engineers” being printed now has a chapter on loudspeakers which goes into this exact thing in some detail.

“So, whaddya think, is the audio signal traveling down the cable in one direction only?”

Again some confusion, YOU are the one who thinks “the signal” travels one way better than the other, my point is “the signal” is a Voltage magnitude referenced AC signal which spends half the time going one way and half the other.

RE: Cable shootout... Are all audio cables the same?, posted on June 23, 2014 at 15:49:04

geoffkait

The only things that propagate at light speed are photons and an electromagnetic wave such as light (photons) or RF, X-rays, etc. The reason electromagnetic waves travel at the speed of light is because the wave is composed of photons which, you will recall, have a constant speed in the universe - the speed of light, 186,000 miles per second. Maybe voltage is also composed of photons, you tell me.

RE: Cable shootout... Are all audio cables the same?, posted on June 23, 2014 at 16:09:03

tomservo
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The only thing that propagates at the speed of light is electromagnetic radiation in a vacuum, light (also electromagnetic radiation) traveling through glass, water or other materials travels slower and as a result we can have lenses which bend light.

Electromagnetic radiation propagates in two components, a Voltage field and 90 degrees apart, a Magnetic field and that is much like sound which propagates with two components, the familiar “sound pressure” and 90 degrees apart the less well known particle velocity.

With light however the wavelength as one departs the microwave range into far far infra red, the wavelength becomes too short to discern the two parts separately. None the less, light and radio are a continuum.

It remains that the “signal” we call analogue audio, is an alternating voltage referenced signal which propagates at the cables velocity factor. This may help, from an area where this is critical and well studied;

http://www.radio-electronics.com/info/antennas/coax/coax_velocity_factor.php

velocity factor

RE: Cable shootout... Are all audio cables the same?, posted on June 23, 2014 at 17:46:31

geoffkait

Exactly what I have been saying all along. Hel-loo!! The velocity is of the electromagnetic wave. You still have not shown that the electromagnetic wave is alternating directions, however. So I remain unconvinced. Besides EVEN IF the EW IS CHANGING DIRECTIONS, which I actually doubt, the only direction that counts is the direction pointing toward the speakers from the amp. So, directionality of wire can still be real and still be audible since one direction would be more "favorable" to the signal traveling toward the speakers. Or, in the case of ICs, more favorable to the signal traveling from source to amp.

RE: Cable shootout... Are all audio cables the same?, posted on June 23, 2014 at 19:26:26

tomservo
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What electromagnetic wave are you talking about, cables at audio frequencies are FAR FAR too short to have any transmission line or wave behavior and there is no standing wave in audio cables.

To be clear too, the audio signal isn’t an electromagnetic wave, it’s a Voltage referenced signal, it is so starting at a microphone and ending with a loudspeaker and there isn’t anything about cables that make them “signal directional” with an AC signal.

If you don’t believe it’s ac, get an oscilloscope, set it to a DC or ground reference and look at any analogue signal you choose, or if you do digital, get a wave editor like cool edit and zoom in on the wave form, what do you see? Ans, a signal that goes positive and negative, just like the air pressure than we hear as sound.

Now I don’t doubt you can hear a difference, but it isn’t related to the signal passing through it and if this effect were actually present, it would be part of RF engineering where everything becomes more of an issue. Hell-ooo the effect is because you know which way the arrow points and when it’s “right’.

RE: Cable shootout... Are all audio cables the same?, posted on June 24, 2014 at 03:26:27

geoffkait

We're a long way from a meeting of the minds. The article you linked to states the audio signal is an electromagnetic wave and most references also state that the audio signal is an electromagnetic wave. It makes no sense to say its a voltage or that the voltage has velocity as you claim. As I have already stated on more fhan two occasions the signal much be electromagnetic because only photons can travel at light speed or near light speed in a medium. I never said the cable is not AC, the only question is what does AC really mean. As I said in my previous post, EVEN IF THE ELECTROMAGNETIC WAVE ALTERNATES BACK AND FORTH ALONG THE CABLE AS YOU CLAIMED AT ONE POINT IT IS THE DIRECTION TOWARD THE SPEAKERS THAT COUNTS. So wire directionality would be important even if the audio signal is alternating. Hel-loo!

As far as wire directionality goes it is obvious when listening even when there ARE NO ARROWS to influence you. Are you that easily influenced? This is true for speaker cables, interconnects and fuses. Hel-loo! I suspect this might be another case where someone has fabricated a theory of convenience to explain a strongly held belief that wire directionality is false and ALL EVIDENCE to the contrary further buttresses that belief.

Going further, what this whole issue of wire directionality really means is that ALL internal wires and cables, crossovers, transformers, capacitors, etc. should be fabricated with the correct direction established and indicated with arrows and that all speakers, electronics, and cables should be manufactured with wire directionality in mind. Anything less is just hiding one's head in the sand.

RE: Cable shootout... Are all audio cables the same?, posted on June 24, 2014 at 06:31:50

tomservo
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Wow, a "gold star" for persistence, the consummate audio salesman type, unfortunately untainted by engineering and also possibly hallucinating.

For example for hallucinating, what article are you talking about that “I linked” talking about directionality and a number of your assertions such as; “Sine waves are not alternating current. Nor do audio signals produce alternating current. Hel-loo! The audio signal is the thing that's moving at near light speed down the track. “???.

The thing I linked here was about cable velocity which is 100% engineering related and says NOTHING about audio or directionality unless you can read what wasn’t printed or intended.

At the same time you avoid addressing any of the things I brought up and say silly things like;
“Nor do audio signals produce alternating current. Hel-loo!

Hel-loo Geof, your right we ARE a LONG way from a meeting of the minds, you’re talking the language of alchemy and audio trinket sales, I’m talking the language of chemistry and electronic engineering and design no wonder there is no common ground and your unable or unwilling to answer even my simplest engineering question with a direct answer like;

“Ok, i am game, in exactly what way are they directional and how large is that effect an alternating signal like audio?”

Sure we can hear things, but we also "hear" things unrelated to what arrives at our ears and influenced by what we know and believe.

If this signal directionality and “audio is not an ac signal ”is a real effect, it exists in the electronic domain, not just in one’s head, show me some evidence of that.

Sure I am skeptical, audio has been a lifetime love, I have worked in both electronic and RF engineering most all my life, much of that time designing circuitry that works, even flown on the space shuttle (sts-7 and sts-51a).
This makes it rather hard to believe here is something about audio traveling down cables that isn’t present at all at frequencies above 20Khz or below 20Hz..

You said “I suspect this might be another case where someone has fabricated a theory of convenience to explain a strongly held belief that wire directionality is false and ALL EVIDENCE to the contrary further buttresses that belief.”

Show me engineering evidence, any evidence at all, some mechanism, or measurements this exists in audio for directionality, where it doesn’t for RF, more arm waving and smug salesman talk won't do it..

RE: Cable shootout... Are all audio cables the same?, posted on June 24, 2014 at 06:50:21
geoffkait	I was quite sure this "discussion" would deteriorate into name calling and silliness. Thanks for making my prophecy come true. Some people refuse to come out of their caves.

RE: Cable shootout... Are all audio cables the same?, posted on June 24, 2014 at 07:32:19

tomservo
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Similarly, from the start, i pretty much assumed you couldn't answer in an engineering fashion or answer even one question honestly, but is was fun to see how far you would bend before bailing out.

Hel-loo

Fwiw, Engineering isn't silliness, its what honest design depends on but it's never to late to learn something new, hence a number of sincere attempts to get you to explain directionality leading to the conclusion you can't and are an alchemist in a world of chemistry.

RE: Cable shootout... Are all audio cables the same?, posted on June 24, 2014 at 07:41:49
geoffkait	More jibber jabber from the man who lives in a cave. An engineer, a real engineer, would have gotten to the bottom of this whole wire directionality thing a long time ago. You rely on phoney arguments like "voltage velocity" and other pseudo engineering terminology. It's apparently true what they say, you can't teach an old dog new tricks.

RE: Cable shootout... Are all audio cables the same?, posted on June 24, 2014 at 09:30:55

tomservo
Manufacturer

Posts: 8181
Joined: July 4, 2002

Why Geoff I am glad to not be your kind of engineer in fact I am an inventor and here are a couple samples of what I have done “living in a cave” as you put it;

The first invention link might even appeal to you especially as it looks like magic to most and all are the result of understanding how things work;

http://howsyourrobot.com/2013/07/19/acoustic-levitation-video/

https://www.google.com/?tbm=pts&gws_rd=ssl#q=thomas+j+danley&tbm=pts

Would “your kind” of engineer have inventions which changed the way things are done, some examples;

https://www.google.com/search?q=danley+sound&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=np&source=hp

Or would “your kind” of engineer have changed the face of large scale sound in just a few years?
Have you ever been to a stadium and heard what concert speakers sound like?, they don’t sound like this.
Pop on some headphones; By this fall, 4 years after introducing the products, we will have provided the sound systems for more than half of the 100,000 seat stadiums in the USA.

https://www.dropbox.com/s/oyosfc3adc6j1du/20130723135350.mts

https://www.dropbox.com/s/tnsw5mb4v5vdlwq/20120726122124.mts

https://www.dropbox.com/s/1nhx980w24ehxls/20131208154446.mts

Soon there will be several recording studios using our smaller Synergy horn loudspeaker systems for monitoring audio too and next season we are introducing a new “stereo capture” system which can capture an entire hemisphere, try a recording or two, again use headphones.

https://www.dropbox.com/s/jq5n4gj4mpptjpn/TrainStart.wav

https://www.dropbox.com/s/8208qvei00qxzxz/parade%20section3.wav

So, this is sort of fun, teach me a new trick Geoff, somehow in some way if at all possible, try to describe how / why audio signals aren’t AC and audio cables and wire are signal directional.

Tom

-75 dB, posted on June 24, 2014 at 21:07:56

Tony Lauck
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Posts: 13629
Location: Vermont
Joined: November 12, 2007

I nulled out two of the cables using the WAV files. The null was at -75 dB relative to the original music. By cranking up the volume by +26 dB and listening carefully I could hear the difference, which sounded like quiet music in the background, not noise or distortion.

I would have to see an indication of repeatability (multiple tests with a given cable, with and without disconnecting and reconnecting and done in a random order by cable) before I would attribute any differences to the cables themselves and not some other aspect of the experiment. It's all too easy to conduct experiments that one believes to be measuring one thing only to discover one was actually measuring something else.

To put things in perspective (not sure that's quite the word) I've seen a number of audiophiles report big differences in files that differed only in the low order bit of a 24 bit format and other files that were identical except for a few hundred extra leading zero samples at the start. In one case a file that differed only at -138 dB was described as "completely trashed".

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

RE: That is a very cool article and test, which sums up my feelings..., posted on June 24, 2014 at 21:10:46
Tony Lauck Audiophile Posts: 13629 Location: Vermont Joined: November 12, 2007	No they won't stone you. They will tell you politely to go discuss the issue in Prophead. If you do it a second time you will be banned from the Cable Asylum. Tony Lauck "Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

RE: -75 dB, posted on June 25, 2014 at 13:19:12
bjh Audiophile Posts: 18614 Location: Ontario Joined: November 22, 2003	Try to speak clearly and simply, are you suggesting people should not hear difference in this particular comparison?

RE: -75 dB, posted on June 25, 2014 at 13:23:21

tomservo
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Posts: 8181
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Hi Tony

Cool, somebody looked!
With a null -75dB down and IF the spectrum you heard was that of the recording, for a signal cable like these, if driving a 5K load, a difference of about 7 Ohms in series R would do it.

If this were a speaker cable, that much difference could be the result of one cable having about 1/1000 of one Ohm more resistance than the other.
(Assuming an average load Z of 6 Ohms).

If the null had more high end, that would be from one having a little more series L than the other or signal cable, parallel C. Any form of non-linearity would be a "difference" and be most audible (like when you use this on electronics etc).

“I would have to see an indication of repeatability (multiple tests with a given cable, with and without disconnecting and reconnecting and done in a random order by cable) before I would attribute any differences to the cables themselves and not some other aspect of the experiment. It's all too easy to conduct experiments that one believes to be measuring one thing only to discover one was actually measuring something else.”

Sad but true and same for the -138dB.
Best,
Tom

RE: -75 dB, posted on June 25, 2014 at 13:37:56

Tony Lauck
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I reported what I heard and what I measured. It is not my place to say what other people "should" or "should not" be able to do.

I doubt there would be agreement on what it means for someone to "hear" these differences. (It is necessary to agree on the size of the pin before debating how many angels will fit on it.)

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

RE: -75 dB, posted on June 25, 2014 at 14:06:39
bjh Audiophile Posts: 18614 Location: Ontario Joined: November 22, 2003	If you ever grow a pair let me know, I might then try asking again. Lol

RE: -75 dB, posted on June 25, 2014 at 14:16:08

Tony Lauck
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As far as I could tell, the levels were matched to a tiny fraction of a dB, i.e. to all the significant digits displayed by Soundforge. This was surprisingly good for analog comparisons. A slight drift in temperature could cause a gain differences needed to get a better null. One thing that I noted was that the two files were perfectly synchronized. This indicates that the DAC and the ADCs involved were run off of a common clock for both runs. Otherwise, there would have been clock drift across the file with the samples going in/out of phase.

I've done a lot of null tests, usually digital to digital involving comparison of sample rate conversions of one sort or another. These rarely give 75 dB nulls, even when there is no theoretical reason for a null to be more than a few dB from the resolution given by the bit depth. (An example is resampling 44.1 to 88.2 and back to 44.1. Getting good nulls was impossible due to sub-sample delays in the filters, fractional gain errors, phase shifts and filter pass-band ripple. Eventually, I figured out how to do this kind of conversion without excessive error, except in the pathological cases where there was energy too close to Fs/2.)

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

RE: -75 dB, posted on June 25, 2014 at 14:26:27
Tony Lauck Audiophile Posts: 13629 Location: Vermont Joined: November 12, 2007	I am not an easy troll, so I won't take your bait. Tony Lauck "Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

RE: -75 dB, posted on June 25, 2014 at 14:29:15
tomservo Manufacturer Posts: 8181 Joined: July 4, 2002	What a -75 dB null means is the difference between the two was 1 part in about 30,000,000. If one were to change the level of the signal you were listening to by that amount, it would be a change of about 1.4^-8 dB, or "pretty small".

Yeah ... and... ? LOL, posted on June 25, 2014 at 17:00:39
bjh Audiophile Posts: 18614 Location: Ontario Joined: November 22, 2003	If you're working up to say something then by all means spit it out.

Impedance mismatches , posted on June 25, 2014 at 21:32:21
Ugly Audiophile Posts: 2912 Location: Des Moines, WA Joined: August 22, 2006	cause reflections. Do you control impedance throughout?

Wire directionality and polarity, posted on June 26, 2014 at 02:57:15

geoffkait

Here is an article by Doug Blackburn discussing the dodgey subjects of wire directionality and polarity that is surprisingly germane to this thread.

Wire directionality and polarity

RE: -75 dB, posted on June 26, 2014 at 06:46:49

tomservo
Manufacturer

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Hi Tony
Man you are lucky to be working in the digital domain where the noise floor is so low. A -75dB null is very low indeed, if one were using an old style HP analogue distortion analyzer, a -75dB null on a Voltage signal would be unreadable.
Of course there are other complications there too haha.

One thing that was puzzling at first but made sense later was that measuring a low distortion loudspeaker, one needed to subtract the amplifiers voltage and harmonics from the loudspeaker (used vector subtraction with an Hp3562) because the amplifiers harmonics could either add OR subtract from the loudspeakers distortions depending on their phase.
Best,
Tom

RE: Yeah ... and... ? LOL, posted on June 26, 2014 at 07:10:00

tomservo
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Posts: 8181
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Hi
I am not sure what you mean but I can explain without using dB which is a log scale and can be confusing.
As the dB scale is commonly used, maybe explain that would be better.

dB in this use refers to the difference between two things, a 3dB difference is a factor of two in power, 6dB is 4 times, 12dB is 16 times, 20dB is 100 times, 60dB is a million times.

So, if the distortion in an amplifier were -40dB down from the real signal, the THD would be about 1/10,000 the power or level of the desired signal or 1/100 the Voltage level.

-75 dB here means the difference between the two is about 1/30,000,000 the power of the desired signal.

Is that much change audible?
Now this is more complicated because ears are not microphones, what we experience as “audible reality” is FAR more than just the sound pressure reaching ones ears and includes what we see and know as well.

It is the lifetime of hearing that has allowed us to learn to use all the weird things our ears do as a function of angle and height, to create the 3d mental image we experience as reality.
That stuff is usually disconcerting to audiophiles as we know nothing else but that experience and yet it is also well known to audiologists that our ears aren’t “flat” in their frequency response at all and have all kinds of complications.
Hope that helps

RE: That is a very cool article and test, which sums up my feelings..., posted on June 26, 2014 at 07:11:45
geoffkait	See no evil, say no evil, but especially hear no evil. How could you face your friends again? ;-)

RE: -75 dB, posted on June 26, 2014 at 08:11:40

Tony Lauck
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Posts: 13629
Location: Vermont
Joined: November 12, 2007

Some of the best digital SRCs nulled out in the -40 dB range.

I worked with an analog computer in the early 1960's. The individual "operational amplifiers" were "chopper stabilized" and were rated to be accurate to 0.01%. By the time you were done solving a problem, e.g. integrating the rocket equation for an ABM system, you would be very lucky if the accuracy was 0.1%.

This machine was part of a "Hybrid" computer. You can see what this looked like in the attached brochure. A real fun teenage summer job, for which I was paid the minimum wage at the time of $1.00 / hour. (Years later, I learned that my boss charged the U.S. Air Force $7.00 / hour.)

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

http://archive.computerhistory.org/resources/text/EAI/EAI.23

RE: -75 dB, posted on June 26, 2014 at 11:16:56
tomservo Manufacturer Posts: 8181 Joined: July 4, 2002	Wow, now that is cool!! What a neat first job too, that must have been so cool (even at minimum wage haha). My first job was taking furniture apart for an upholstery shop and the guy chewed tobacco which was everywhere Yucko. I knew they had analogue computers but i never saw any of them beyond the simple adder circuits. Do you get out to any audio trade shows?

RE: -75 dB, posted on June 26, 2014 at 12:40:35

b.l.zeebub
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That analogue computer reminds me of this:

RE: -75 dB (Redux), posted on June 26, 2014 at 13:22:26

Tony Lauck
Audiophile

Posts: 13629
Location: Vermont
Joined: November 12, 2007

I went back and repeated my difference test (mogami vs. gotham). This time I boosted the level digitally so I could compare the original and the difference without running the risk of blowing out my ears. The difference had a high noise level, and the music was obviously thin and gritty, extremely gritty on peaks. I'm thinking that the DAC was putting out more or less the same signal, subject to a different load, especially a different cable capacitance, but most of the differences (especially the noise and level dependent grit) are probably artifacts of the ADC being boosted by 75 dB. It would be nice to know what ADC was used to capture the output of those cables. I'll bet that the difference signal would have been quite a bit more musical if a clean ADC like the Grimm and been used.
Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

RE: -75 dB, posted on July 7, 2014 at 12:08:56

pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008

At this late date, I don't know if it was Analogue or Digital but I once visited the Sinclair (petroleum) research labs outside of Chicago. A friend of my dads was a chemist in the hi pressure lab and had some missing digits to prove it.
The computer in question was a vacuum tube model with a huge plugboard as in the EAI brochure.
One of the brain guys my dad knew had written a great circle navigation program for this machine. And it worked! Somewhere in my 'stuff' I may still have the 1/4 MILE of punch tape of the program. Only later (mid/late 70s) could you get a great circle navigation program for the then wacky revolutionary HP handhelds.
I don't know how much floor space the computer took up, but the AC system EASILY was enough for a small apartment building!

The provided link shows a video of a WORKING 'Difference Engine #2' designed but NEVER completed by Charles Babbage. I believe the Vid shows the machine built by the Smithsonian to the original plans. One intent was to make a CORRECT trig table for navigation. Up to that time trig tables were hand copied and computed. Lots of errors crept in which made for problems, as you can imagine. Babbage ALSO designed a printer which I don't think has been built to this day.

An early, but certainly NOT the earliest analogue computer.
Too much is never enough

http://www.youtube.com/watch?v=Lcedn6fxgS0&feature=related

RE: -75 dB, posted on July 7, 2014 at 13:41:11
b.l.zeebub Audiophile Posts: 9361 Location: 52deg 28'N,1deg56'W Joined: April 17, 2006	There are two Difference Engines in existence. Both were built by the London Science Museum. One is still there and the other, the one in the video linked, is owned by Nathan Myrhvold and on loan to the Computer History Museum in Mountain View, California.

RE: -75 dB, posted on July 7, 2014 at 13:55:30
pictureguy Audiophile Posts: 22597 Location: SoCal Joined: October 19, 2008	What happened to the one built by the Smithsonian? That's where I first read about it….and they were in process of building it and trying to find the money to build the PRINTER to go with it. Do I mis-remember? Too much is never enough

RE: -75 dB, posted on July 7, 2014 at 15:13:13

b.l.zeebub
Audiophile

Posts: 9361
Location: 52deg 28'N,1deg56'W
Joined: April 17, 2006

The two engines were built by the London Science Museum in '89-'91 for Babbages 200th birthday and in '00 they also built the printer.

The Smithsonian may have one of the engines based on the Babbage design and built by the swedish lawyer and inventor Per Georg Scheutz and his son Edvard. They sold one to the US gov in 1860. I can't find anything that may indicate that the Smithsonian ever built one for themselves.

RE: -75 dB, posted on July 7, 2014 at 15:36:21
pictureguy Audiophile Posts: 22597 Location: SoCal Joined: October 19, 2008	Must be that pesky brain cell again. Too much is never enough

Directionality, posted on September 2, 2014 at 19:50:15

Old nuff 2 no better
Audiophile

Posts: 516
Location: Upstate NY
Joined: September 3, 2007

I think a lot of the nonsense about directionality comes from cables (Monster comes to mind) with direction arrows on them. It has nothing to do with signal flow, but everything to do with good shielding practice. There's a rule that says signal current should never flow in shields. The usual practice is to use 2-conductor shielded cable, and only connect the shield at one end. The usual end to connect the shield is at the driven end because that's usually the quieter ground. Thus, they put an arrow on the cable that points to where the load should be connected. You can plug them in either way and they'll sound exactly the same, though possibly noise will be a tad higher or lower one way or the other.

FWIW, I can't hear the difference between interconnects. Did a test some weeks ago on the matter here-

Interconnect Tests

That's weird., posted on September 3, 2014 at 01:31:05
geoffkait	I can hear directionality in interconnects VERY clearly. One direction relatively sucks. Same with fuses. Didn't you get the memo? All wires are directional, in the audible sense. Maybe you are "insensitive" to directionality. Lol

RE: That's weird., posted on September 3, 2014 at 08:05:42
Old nuff 2 no better Audiophile Posts: 516 Location: Upstate NY Joined: September 3, 2007	Darn, that memo was obviously sent through a cable in the "wrong" direction, so it never arrived here, or perhaps it arrived before it was sent and I missed it ;-)

Ok this test reveals there are differences and some might find that enlightening., posted on October 13, 2014 at 10:57:47

Goober58

But it doesn't reveal any useful information - the differences are all relative to the system used, as well as our playback system.

So if the point is to reveal there can be differences then the test seems to be succsesful.

However it means nothing in terms of what or even any differences will be audible in a different system. And no audible differences in another system may have nothing to do with that systems resolving power.

If a system is susceptable to interconnect differences then by all means find the most appropriate interconnect. Just remember in the future when making component changes to find the best sounding interconnects again. My experience sometimes more expensive interconnects are better, sometimes they are worse.

Me, one the other hand, buy equipment based on how well it works with my already established system. Equipment that doesn't better what I already have with my current interconnects isn't worthy of a better cable - unless the review comes with cables to be included in the test - which BTW has only happened with components that I have ended up rejecting (sometimes after buying). And unfortunately these cases the more expensive cables purchased for the device prove useless going forward.

RE: Directionality, posted on April 26, 2015 at 16:59:36
pictureguy Audiophile Posts: 22597 Location: SoCal Joined: October 19, 2008	Geoff: wanna let me scramble your cables and randomly reconnect or NOT? You than come into the room and listen. Tell me what is or isn't different. We can do this 3 or 4 times, but 20 would be statistically valid. Let me know when I can drop by and we can begin testing your hypothesis. Too much is never enough

RE: Ok this test reveals there are differences and some might find that enlightening., posted on April 26, 2015 at 20:44:20

pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008

Goob,
This is the 'mystic dart throw' approach to selecting a cable. You talk to friends and gather as much anecdotal evidence as possible, than expectation bias takes over and the New cable in town wins by a landslide.

The other approach would be to try to coorelate some measurable to cable performance and somehow vet the testers. In the context of the test and tested cable, can anything be measured which makes sense in this regard?
A reasonable and known example would be a high capacitance cable acting as a hi-cut filter.

Too much is never enough

RE: Directionality, posted on January 31, 2016 at 08:19:59
geoffkait	Unfortunately your little experiment would prove absolutely nothing. A much better experiment is take an unshielded pair of interconnects and reverse their direction. Which direction sounds best? Or even easier for the uber skeptics among us just flip a stock fuse. It's not rocket science.

Propeller Head Plaza

Cable shootout... Are all audio cables the same?

131.114.2.201