[Martyn]

Hi, guys. This is a quick write-up on a test I’ve just done with some home-brew speaker cables. To make a long story short, I was reading a while back about niobium - a rare metal that has super-efficient, hyper-conductive properties when cooled to an extremely low temperature - nearly absolute zero (-270 C). Anyway, I was reading about this stuff and thinking that it would probably make pretty good speaker cable (!), when it occurred to me that plain old copper becomes a pretty good super-conductor at those kinds of temperatures. Of course, you can’t get to those temperatures in your living room, but it started me wondering just how close you could get and whether it would make an audible difference.

I called up my local industrial liquid gases supplier who offered me liquid nitrogen at -193 C (OK, it’s not absolute zero, but it’s still pretty damn cold). Apparently this stuff is not hard to manage, because it’s the same stuff that doctors use to burn off warts. Now if you could set up a circulating refrigeration system using liquid nitrogen and use it to cool your speaker cables, you’d end up with vanishingly small resistance… almost super-conducting!

Of course, it’s not without its difficulties. The first problem is that the liquid nitrogen would destroy conventional electrical insulation instantaneously and the copper refrigeration pipes (I don’t know what else could be used) would short the cables. So it would require a material that is a good electrical insulator and a reasonable thermal conductor that could tolerate extremely low temperatures. So what if you ran a ceramic tube co-axially inside the nitrogen-filled copper refrigeration tube, and then ran a bare copper speaker wire inside the ceramic tube? The problem now is how to seal the ceramic tube to the copper tube. I still haven’t entirely solved this, but I’m getting close (maybe 98%).

If you take a look at the photograph (http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1389&pos=5), you’ll see a couple of copper tubes connected in a loop so that the refrigerant, liquid nitrogen, can circulate. All this takes is a small refrigeration unit and pump from a lab supply company. I started to peel back the insulation a little to show the ends of the ceramic tubes (white) and the speaker wires, but the system started icing up immediately. This is probably a good time to say that I’m not a physicist and that this rig is only a first prototype. I made it out of ½” rigid copper tubing and Romex wire because that’s what I had in the garage, but I’ve no doubt that you could use 3/8” soft copper (or smaller if you can find it) to provide some flexibility, and a very light gauge conductor. Everything could be scaled down too, including the lab equipment.

OK, but how does it sound? Well, quite remarkable! With so little getting in the way to slow down those little electrons as they whiz from A to B, transients are super-fast, blacks are absolutely pitch black, and I’m hearing soaring highs that I thought were out of my audible range – even my dog is paying attention! The spaces between notes are longer with crisper edges, and the excessive warmth or irritating buzz that is typical of some amplifiers is gone. This seems to be true for all types of music, but especially blues and cool jazz. The sound stage is now truly enormous and seems to wrap around you and embrace you with startling emotional reality. The presence is so real it’s almost palpable; it’s just “being there”. What else can I say?

In short, this project has taken my system to the next level and beyond. All that remains is to refine the design, perfect the seals, plumb it into the walls of my living room and move the refrigeration equipment into the basement. As a bonus, with a simple add-on I can flash-cool a can of beer in about 20 seconds. Life doesn’t get much better than this! Cheers,

Martyn

[whubbard]

Wow,
I must say that that is a very interesting idea, and I'm highly impressed. I have not personally worked with liquid nitrogen before, but do you just have a tank in some sort of a loop system, or how have you set it up?

Also, not to put a damper on this, but copper, even at 0K will not have zero resistance because of the impurities. At 80K, the resistance will be less then room temperature, but I think it is something you should measure. I would love to see what the actual drop is. I wonder if there are some other materials worth trying out.

I think you might really be onto something here, and I will follow your expiriments on this subject with great interest.

-West

[Russell Dawkins]

And a happy April 1st to you, too, Martyn. 

[kyrill]

to be honest i forgot it is 1 april and took it seriously
great story Martyn
So i was thinking... if you take the mono amp to the speakers you can make speaker wires of 2 inches length
the same lenght that is not cooled

[denjo]

The greatest inventions often start with a proposition that is unbelievable or meant as a joke or said in jest!  Martyn, who knows, you might have something going with your idea that will push the limits of audio excellence and perhaps become a reality one day!

"Benjamin Franklin: Bright Idea?

"One of Benjamin Franklin's most famous innovations started off as a joke. In 1784 he wrote a humorous letter to the editor of a local newspaper suggesting that everyone set their clocks ahead one hour during the summer months to take advantage of the longer daylight hours, and remarkable enough, people actually adopted the idea of daylight-savings time."


Franklin, Benjamin (1706-1790) American statesman"

Best Regards
Dennis

[Hank]

And a happy April Fool's day to you, too! 

[whubbard]

Oh Wow,

I got played.

[grsimmon]

Funny stuff,  but this one's no joke. 

In 1990 I was in high school,  and would work as a janitor in the summer for my school district to earn $.   One of our jobs was to get chewing gum off the bottoms of tons of desks  as part of the big cleanup.  At those moments I hated my classmates.  Anyways the head guys would give us these canisters that just said  "chewing gum remover".  At first I thought WTF could this stuff be, must be nasty chemicals to dissolve gum,  but realized that it would freeze the gum instantly and make it way easier to scrape off.  (In retrospect I'm pretty sure it was the same liquid nitrogen stuff they use at doctor's offices).   

One of my friends and I caught on fast that the spray was not just cold but super cold,  so we set about freezing all kinds of stuff, including ourselves.  We both happened to have plantar warts that summer,  and we said what the heck,  and we sprayed the warts and sure enough it worked and they never came back.   Did I see this correctly on TV that they now sell this kind of stuff over the counter at stores / pharmacies?  I know almost nothing about cryogenic treatment,  but just curious,  could that kind of spray work on cables and such? Crazy stuff....

[jneutron]

And a happy April 1st to you, too, Martyn. 

Darn..and I was soooooooooo interested..I was falling for it big time...wishful thinking on my part.

BTW, most electrical insulation is still good at nitrogen temperatures.  The problem arises when the bend radius is small, or you try to flex it while cold.  Kapton or tefzel works just fine.  Kapton still flexes at liquid helium temps.


Get some G-2 cable from american superconductor.  It's good to 100 amps, and would run 5 amps easily in a 20 tesla background..

Cheers, John

[Martyn]

Thanks for your comments, fellas. I get a kick out of constructing these things. Of course, it's not so much fun being on the receiving end and I'm always a little nervous about any discomfort the recipients might feel, so I'm pleased that you appreciated the entertainment value and I congratulate those who owned up to being fooled. I thought that my penultimate paragraph with all the sonic experience BS would be a dead giveaway, but maybe we've become too accustomed to reading such drivel.

I agree with Dennis' comment about inventions. It's interesting to note that the best sci-fi writers have an uncanny way of predicting the future; it's also interesting how easily we can be swept along by a little pseudo-science!

Thanks for your good humour,

Martyn

[sbrtoy]

You never know how far someone will take a wild idea...look at all the DIY plasma tweeters being constructed...

[JoshK]

I thought it was funny.  I was fooled for about half way through the post.  I was about to post that this was complete silliness and then it dawned on me.

[jneutron]

I thought it was funny.  I was fooled for about half way through the post.  I was about to post that this was complete silliness and then it dawned on me.

Why is it complete silliness???

If you stick with 4 nines annealed, you get about an order of magnitude conductivity improvement at 77k.  Drop it to 4.5k, and you pick up another two orders of magnitude..

That's not silly...heck, for a #12 wire, you pick up almost 17 milliohms improvement for a 5 foot run!!  That ain't small!  Noooosirrrreeee..

Course, it'll cost ya about three thousand dollars a day to keep em cool...but hey, that's what audio is all about...

Cheers, John

[whubbard]

It is funny that I was fooled so badly by this, but you actually did have some interesting points you made, that made it decently possible.
I had just been reading about superconductivity when I came across this post, so I thought that it just maybe made some sense.
I also I'm a pretty much all DIY person, because I'm sick of the companies tacking on crazy prices for all the costs they encounter along the way. For me, I'll pay for R&D, but I'll do everything else myself, thank you.
I apply this method to cables to. I really like Ven Haus's Designs, and I'm currently making 6 Pairs of his cat 5 wire for my Orions, although I might have to use something simpler because its a huge time commitment to make those things.
I also hate silly little Brilliant Pebles and Orange Clock junk, it really hurts the audio community in my opinion.

Well, hope you had a great April Fools at my expense.   

-West