The Headcase Stax thread

[nopants]

is this some sort of elaborate troll

[Spork]

7 minutes ago, nopants said:

is this some sort of elaborate troll

Oh c'mon.

Elaborate????

Troll???

Did I use the wrong emoticon to indicate I was joking?

[arnaud]

His account must have been hacked!

[Craig Sawyers]

2 hours ago, kevin gilmore said:

note:

liquid hydrogen is stupidly dangerous.  besides which you are unlikely to get anyone to sell it to you.

liquid nitrogen is better, and very cheap.  been there, done that many times, no difference can be detected. cryo'd cables,cd's,tubes, flowers,bananas...

liquid helium is even colder, and very expensive

I once got involved in a project for a superconducting gravity gradiometer, around 20 years ago. This was for the GOCE mission (Gravity and Ocean Circulation Explorer). Because the cryogens were the closest uncontrolled mass to the gradiometer, we had to constrain them. One of the design team came up with a cryogen cycle in which there was a solid hydrogen outer shield (which sublimed to space through a capillary, and what was left was held on a wire mesh) and a liquid helium inner vessel that cunningly moved around the phase diagram so it was always full - for the 1 year mission anyway. So no gas-liquid boundaries and uncontrolled motion.

I presented this solution to ESA, and they were very unhappy about the solid hydrogen. I must admit I found that puzzling since it was sitting on top of a rocket with hundreds of tons of high explosive propellant in it. Fortunately we substituted solid neon, which worked just as well, but was substantially heavier. 

[wink]

9 hours ago, Craig Sawyers said:

Or high temperature superconducting power and speaker cable? http://www.amsc.com/documents/hts-cable-systems-for-ac-networks/ . Might be a problem in terminating it into Stax 'phones though 

This would NOT stop any incompetent cable manufacturer......

2 hours ago, Spork said:

@spritzer - I guess you're going to tell me "proper" Hi-fi fuses don't improve sound either?  

That all depends on the individual's version and perception of sound improvement....    

But, then again,    If it costs buckets more, it's gotta be buckets better, right....   ?????   

And the name HIFI-Tuning.com - which verion of "Hi-Fi" is it, or can it be tuned to...?   

And, according to the symbol, it must be DC blocking, therefore directional.

Must be some bypass cap to allow 50/60Hz through to fit in a fuse cartridge.

[Spork]

From the website:

Upgrade fuse pioneers, HiFi-Tuning, have released a new series of fuses without the gold-plating of their standard fuses. These unplated SilverStar fuses are pure silver, tip to tip, and this consistency of materials delivers an even faster and more open sound than the gold-plated version.

So far only available in the most popular fuse amperages, and only in the small (.75"/ 20mm) size, fast and slow blow. Plans are in place for the large SilverStar fuses sometime later this year.

More good news: The small SilverStar fuses are $29.95 each , which is  $5 less per fuse than the gold-plated versions.

 

- It's silver - will sound brighter no? faster and more open...

- But, cheaper than the gold plated ones, so could not possibly be as good.

- Guessing it will make any cheap POS sound HiFi. Must reduce THD and improve SQ in any device, thereby making it High Fidelity.

- "Pure silver tip to tip". Must be using some kind of proprietary "one-way" silver.

- See above.

[JimL]

13 hours ago, kevin gilmore said:

actually the MIT cables are more than a resistor to ground.  There is all that hot-glue. Dripping piles of hot-glue.

Ah, but it's special audiophile-grade hot glue.  Very exclusive.  Very expensive.

12 hours ago, wink said:

I'm waiting for the Bose-Einstein Condensate cable that slows down the electrons to a walking pace.

It means you can enjoy the music for longer............     

But requires the very expensive audiophile electrons with a spin of 1.

[wink]

.... and with a bit of quantum entanglement, voila, dual mono wherever you like..... 

Edited December 17, 2016 by wink

[Sechtdamon]

13 hours ago, kevin gilmore said:

note:

liquid hydrogen is stupidly dangerous.  besides which you are unlikely to get anyone to sell it to you.

liquid nitrogen is better, and very cheap.  been there, done that many times, no difference can be detected. cryo'd cables,cd's,tubes, flowers,bananas...

liquid helium is even colder, and very expensive

Dr. Gilmore I was being sarcastic. I do not believe cyro bs. But thanks for the notes. The info you gave can be useful for overclocking tests for CPU and GPUs.

[DefQon]

Used LN2 many times in the past before in copper pots for overclocking CPU's. It is indeed awfully cheap compared to the prices of liquid helium.

[Craig Sawyers]

General rule of thumb is that liquid nitrogen is about the same price as milk, give or take, for about a gallon of each. Bulk price is much cheaper than milk.

[wink]

.....    and, if you drink a glass of liquid nitrogen, you won't need any more milk......... 

[Skooby]

May be I should follow instructions here to get my own liquid gases:

 

[Craig Sawyers]

That was interesting. For seven years in the '90's I ran engineering at Oxford Instruments, and apart from some outrageously complicated superconducting magnets, we pretty much had the world market in dilution refrigerators. These are the leaping-off point for many techniques to get even colder, using processes like adiabatic demagnetization.

Anyhow, the dilution fridge works by a really strange quantum mechanical effect using a mixture of regular helium 4 and a lighter isotope of helium 3. As with all these cooling processes (brought out in the video) it is multi-stage using a series of heat exchangers until at the bottom of the machine is a mixing chamber less than the size of an ice hockey puck. In this the helium 4 becomes a superfluid and sits at the bottom, and helium 3 floats on top and has the viscosity of corn oil. The hotter atoms of helium 4 diffuse upwards into the helium 3 (no viscosity, remember), and a truly impressive pump attached to the mixing chamber sucks these hotter helium 4 atoms out. That shifts the equilibrium point, and the next hottest helium 4 diffuses upwards, etc etc. We designed and shipped products using this process to labs around the world - about 1 per week - which produced a base temperature somewhere between 1 and 3 milli-Kelvin.

A long way above pico-Kelvin sure. But the race for ever colder temperatures all starts off with a dilution fridge - other than the Bose-Einstein crew, which use a different cooling process altogether.

Anyhow, here is the business end of a dilution fridge. The thing at the bottom is the mixing chamber, the disc-like things are a series of counter-flow heat exchangers filled with sintered silver, and the copper coil has a capillary inside and is the next highest temperature. Not shown is something above all that called the "1K pot" which is what is says on the tin - so everything in that image sits at less than 1 Kelvin, and getting colder as you go towards the bottom of the image until 1 milli-K in the mixing chamber.

 

Edited December 18, 2016 by Craig Sawyers

[nopants]

we need a separate thread for talking about instrumentation

[Craig Sawyers]

Oh wait - this is the Stax thread, right.

This is head-case though 

[wink]

The bottom chamber is where we cryo our Staxxen.....  

Back on topic.....   

[nopants]

Oh wait - this is the Stax thread, right.
This is head-case though 

nah i meant as in i want to read more about haha sorry if that came off the wrong way

[Craig Sawyers]

29 minutes ago, nopants said:

nah i meant as in i want to read more about haha sorry if that came off the wrong way

 

Seriously though - you're right. In defense I got sucked into a conversation and lost track of the thread subject 

[kevin gilmore]

actually my price for a gallon of liquid N2 is $1.60

a gallon of milk is about $4

[Craig Sawyers]

Yup - I did say "about". But as a reasonable ball park those prices are comparable enough. What would be the comparison for LHe? A fairly decent quality wine I was thinking.....

[kevin gilmore]

I pay $45 a gallon for liquid helium

I get back $16 a gallon for the equivalent gas generated from a gallon of liquid helium

The new liquefier we bought to recycle the recovered helium gas was $500k which did not include the raw gas compressor ($130k) the storage bag ($15k) and the storage torpedo's which are still in use from world war 2, and $20k for a 2000 liter storage dewar.

To continue to get government grants we are required to recycle helium.

[Craig Sawyers]

I forget now which liquefier we bought when we moved from Eynsham to Tubney. But it was big. Because this was cryogenic systems manufacture on a large scale we had to deal with a serious amount of helium. Every magnet could take typically 5 (and sometimes many more) training quenches. And because these were in less than efficient test cryostats, each quench took at least 100 litres of helium (for cool down and reservoir). So 500 liters plus per magnet, at a production of one a day or thereabouts. Not counting all the other systems (variable temperature inserts, He3 and dilution fridges). So a daily use of 600-700 litres was typical, which had to be compressed and stored (two monster pressure tanks outside), and then liquefied 24/7.

Edited December 18, 2016 by Craig Sawyers

[Tinkerer]

9 hours ago, kevin gilmore said:

To continue to get government grants we are required to recycle helium

It's because the natural sources are so limited. Imagine if the federal government hadn't nationalized the reservoir in Texas all those years ago. Of course that might bite everyone in the ass now that the public production part of that agreement is coming to an end.

[kevin gilmore]

don't I know it.  in 10 years I doubt we will be able to continue to run 9 nmr magnets, 3 mri, and 5 ft's, plus all those low temperature epr experiments.

luckily I will be retiring in 2.5 years or less

there are 400mhz superconducting liquid nitrogen magnets, but those are toys.

Edited December 18, 2016 by kevin gilmore