Can you hear the "directionality" of interconnects and speaker wire? Kevin LaTour can.

About as much as Dachshunds need to go away. Yes, those little guys (and gal), can run...

Looks like national dachshund day was 6/21.

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Actually no, my comment was in a response to you bringing up test equipment and what can't test equipment test for. I said sound quality in witch this thread is about, can we hear a quality change in the sound of a directional cable reversing it. If you took a directional IC and the reason they are terminated differently, on test equipment they will test the same no mater witch direction you put it on a signal analyzer. However that doesn't mean as the OP stated some people can hear a difference in sound quality if reversing the direction.

I personally haven't heard the difference in the couple of directional IC I have if reversed, don't quite remember if I even ever put them on backwards. Also sometimes they just might be terminated in the conventional manner and put cool arrows on them.

As far as speaker cables go sometimes they are wired specifically witch way they go. I have Bi-wire cables that have resistors in them that designate each end and each side as to where they go. But my rule of thumb, like Steve is to default with cables that have arrows and follow the direction. The same goes for the color coding on all cables designating left or right or positive & common, they can be reversed and work but why would you buck against the norm.

I'm also a believer in accumulative effects in building a system, small things add up in the final results.

 

I think there are people (not nearly as many as who think they can) who can hear things test instruments can not pick up. Here are two who I think can:

_ _ e v e

_ e v i n

 

The thing is learning to hear, learning what to listen for in critical listening and detect the changes. Some people can do this, others can't and really while one needs good hearing, it really is the aspect of learning how to hear what's going on. Many of our great mastering engineers are up there in age and don't have the supper hearing ability they did when young. However they have mastered critical listening of very small changes in sound as well as how the whole sounds together and flows.

 

Through lots of blind ABX tests from when I recorded and compared interconnects, I learned other than silver vs. copper, which I can blind ABX pick out, I can not distinguish bw copper interconnects(for RCA interconnects from El Cheapo but with Japan stamped on a plug to Audiotruth Emeraldx3, their mid 90s totl copper cable and for balanced mic cables from the ones that came with my Rat Shack #33-3007 mics to Harmonic Technology Truthlink single crystal). I currently have copper and silver speaker cables but doubt I will test, plus there are other variables changed as well. Do I think I could hear a difference? No. I never want to do another blind ABX test again. Not fun, I have put in my time and then some.

 

Cables just arrived, time to play

note: 175 hours of break-in, lol
At 2 hrs/day, 5 days/week, only 4 months
They must be trippin'

 

Thanks for the correction Ingenieur, just confirmed with a connectivity test. If memory serves, Im 99% certain the Videoquest MAC 3-1 cable (discontinued but they have a newer version) is similar to the Blue Jeans LC-1 cable (Belden, coaxial 75 Ohm) other than shielding so I followed what Blue Jeans did, shield connected at both ends. I think the LC-1 has 2 braided shields (which Blue Jeans say is better at rejecting interference, but at the expensive of higher capacitance) while the MAC 3-1 has a braided/foil shield.

Here is the cable Blue Jeans uses in their LC-1 (LC stands for low capcitance) I thought it was Belden, but was wrong. It is Canare, but still a 75 Ohm, coaxial cable. I'll see if I can find Videoquest's (Audioquest) current version of "MAC 3-1".

Canare Corp.: 75 ohm Coaxial Cables: 75 ohm Video Coaxial Cable(LV-77S)

 

Hang on, the center conductor of the LC-1 is 25 ga. The spec you linked says 22 ga.

I always thought the LC-1 was farmed out from Belden... I will have to look again, but seem to remember it actually being documented on their site.

Their (Blue Jeans) flagship before the LC-1 was the Belden 1505F, it has a 22ga twisted core if memory serves correct. 18 pf / ft. (just checked, it's 17)

The primary change to get the capacitance to the ultra-low 12 pf/ft of the LC-1, they shrunk the center conductor (center conductor and insulator size factor into capacitance). It's also solid core, not twisted.

On another topic, I've often wondered where the line is between shrinking conductor and increasing attenuation....

 

I thought Blue Jeans used Belden cable for all their cables but apparently not. Or maybe they changed what they use in the LC-1, it has been a while. But the current LC-1 page says it uses the Canare that I linked above.

 

Blue Jeans Design Notes: LC-1 Audio Cable Design Notes -- Blue Jeans Cable

 

Take a look at the design notes, I am still reading...

 

Looks like there are two versions of Blue Jeans LC-1. Sorry about that, I did not realize that(or maybe they added the Canare version?), I just skimmed.

"As a result, we recommended Belden 1505F for general analog audio use, and Canare LV-77S (higher capacitance, but slightly better low-frequency noise rejection) for subwoofer use. "

https://catalog.belden.com/techdata/EN/1505F_techdata.pdf

 

There's only on LC-1, it's an OEM Belden-made coax with a double braided shield and small, solid core center conductor. The quote from the design notes above refers to what the company used to recommend before the development of the LC-1. But Blue Jeans also sells other coax cables besides the LC-1, with cable sourced from both Belden and Canare.

Per the Blue Jeans website:

"By shrinking the center conductor to 25 AWG and foaming the polyethylene dielectric, we were able to get capacitance down to an extremely low 12.2 pF/ft, much better than LV-77S at 21 pF/ft. Capacitance can be important, particularly in long cable runs, because it contributes to rolloff of higher frequencies. The softer dielectric material and smaller center conductor, meanwhile, make the cable highly flexible and easy to route. LC-1 is built exclusively for Blue Jeans Cable by Belden, the leader in American communications cable, and is rated CM for in-wall installation in residential and commercial environments."​

 

Im trying to find out the construction of this cable and cant seem to find anything (which is often the case). Im trying to determine if there are other variables (shielding attachment) besides the direction the wire was drawn (AQs explanation for directionality) in this cable. What if AQ is right? And they are on the same page as Kevin?

This is the closest I could get to the construction of this cable (did not spend too much time, so hoping for some help).
History of Purist Audio Design Cables
Revision C, 2003-2009

"Revision C also introduced to new shielding technologies Ferox and Contego!"

I wonder if Kevin could still pick out cable direction after these new technologies were introduced?

If anyone can shed any light on the shielding of the Purist Audio Colossus(or anything else you think is important), that would be great. Thanks!

 

Noise reduced from 12.5 to 10 mV
SNR -67 to -69 dBV
Listening now, no I don't expect to hear a difference since I listen at 50% and those numbers are 100% volume.

I measured capacitance
LC1 ~ 40 pF
Mogami 80 pF
Raised the 15 kHz hump from flat to 1.5 dB.
Audible? Listening now, but highly unlikely with my ears. Lol

 

I measured mine just now:
The LC1 3' was ~40 pF
The Mogami 2c w/shield ~ 80 pF
Thinking about it now, I may have measured + to shield! The c to shield spec is 76...c to c is 11 pF/meter.

I could not get the clip on the same end so pin on one sleeve at the other.
Should have measured on the same end?
Need to ponder, but sure as heck ain't pulling them to remeasure! Lol
What would the cartridge 'see'?

 

Thanks, got busy and meant to respond.... yes, Belden made.

 

Chervokas - if you get time - any thoughts on this?

I'm referring to the center conductor - BJ's choice of 25 ga was due to the effect it would have on decreasing capacitance. But where is the trade off, if lowest capacitance possible is truly the goal, then why wouldn't more cable makers offer a smaller gauge conductor, and hence lower capacitance?

 

I have had these for years use them in my HT setup for my front speakers now. I know I have hooked them up backwards many times and have never been able to tell a difference in the way they sound. I leave them connected the right way still but have never heard a difference in them.

 

Attenuation = 20 log ((V - V drop)/V))
If V = 1 and drop = 0.1 attenuation = -0.9 dBV

Now how to get V drop
V drop = I x conductor R

let's use 25 AWG, 32.3 Ohm/1000' or 0.032/ft
6' cable
Assume V = 2 and input load = 10 kOhm
I = 2 / 10000 = 0.2 mA
R for 2 x 6' or 12' ~ 12 x 0.032 = 0.39 Ohm
Vdrop = 0.2 mA x 0.39 Ohm = 0.08 mV

attenuation = 20 log((2-0.08)/2) = -0.35 dB
in most cases this can be ignored

 

So just keep increasing conductor size to zero with no impact? I don't follow.

In laymen's terms....

 

Actually, they wouldn’t test the same if a ground loop is involved, which is the reason for the particular design.

So again, please start a new thread if you want to discuss what can and cannot be tested. In short, cannot be tested == qualitative, can be tested == quantitative.

 

Whoops I meant decreasing.

 

Obviously there is a limit. Lol
You must have SOME wire!

But any RCA cable attenuation in the line level audio range will not be an issue unless you are talking about very long runs and low input impedance (<10 kOhm). Noise would be a greater concern imo.

The phono cable is critical. It must be selected based on your cartridge manufacturers specs for capacitive loading (cable plus phono amp plus ~ 20 pF for the tonearm). It must also have good noise rejection.
The current is extremely low and susceptible to distortion
I = 5 mV / 47 kOhm ~ 0.1 uA

 

Obviously the trade off with a smaller conductor is greater resistance and resistance losses. @Ingenieur has shown the math on that. It's negligible for the application of carrying a circa 2V audio frequency signal say 6 feet. One might be just as fine with higher capacitance than 12 pF/ft in most audio applications (other than maybe phono applications) too. It's a design choice and a trade off, as things in audio typically are.