View Full Version : Liquid Cooled Sansui?


Vintagaholic
06-03-2004, 07:11 PM
Anyone know the story on this approach to keep things cool or is this a home made upgrade?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=67785&item=5703057451&rd=1

joelll
06-03-2004, 10:49 PM
I don't know the complete story, but I know the Sansui 9900z receiver also has liquid cooling. There's refrigerant in the tube that connects all the fins. There's also an AU-D11 on ePay right now that has a picture of the inside showing the liquid cooling unit.

I also found a Technics integrated amp with liquid cooling, SU-Z700 or something like that, set out with someone's trash. And there's a Sansui AU-

All-in-all, I think it was more a marketing gimmick than anything else. It's not used in audio anymore as far as I know.

1420-1503
06-03-2004, 11:49 PM
My AU-D9 has that too. I don't know if it's better then conventional systems but the thing stays cool all the time.

ps, to buy an amp just because it has a refrigerated cooler is insane. There's not even a foto of the faceplate!

BeatleFred
06-04-2004, 12:12 AM
Yes, several Sansui models, both integrated amps & receivers, employ the tubular heat sinking sytem (the higher models have a bit more elaborate of a design)- the basic idea has to do with a repeating evaporation/condensation cycle which functions to dissipate heat more quickly via a light, flexible tube, than is possible with fin-type heat sinks.

Also, the power output transistors can then be positioned very close to their driver devices, which elminates connecting wires- and (theoretically) improves the audible sound quality.

B/F

bolly
06-04-2004, 04:25 AM
There's no liquid in them tubes...

bolly
06-04-2004, 05:26 AM
You'll notice that no liquid/coolant leaked out while attempting repairs on my AU-D11.

bolly
06-04-2004, 05:27 AM
Here's what she supposed to look like...

Morden2004
06-04-2004, 06:08 AM
Originally posted by bolly
There's no liquid in them tubes...

You'll notice that no liquid/coolant leaked out while attempting repairs on my AU-D11.



Radiator problems, eh? Try BarsLeak :D

Paul

bolly
06-04-2004, 06:58 AM
Maybe that was the problem all along, all she needed was a flush!

heathkit tv
06-04-2004, 12:24 PM
I've seen liquid cooling in PC's (computers).

Years ago I'd make the summertime shop helpers go nuts by telling them to check out the water pump on a Corvair or VW Bug!

Anthony

qboneus
06-04-2004, 01:00 PM
I have often doubted that there is liquid as per se but possibly a charge of R-12 or r-22 refrigerant.
That way when disassembled or damaged there would be nothing inside of the tube if the gas/liquid mixture leaked.

Anybody know for sure?

Tal

heathkit tv
06-04-2004, 01:09 PM
No Freon has been (legally) manufactured for over 10, maybe 15 years....not sure if that's what was used in any home electronic devices, but as I said earlier, there are/were home PC's that used liquid cooling. A lot of projection TV's use liquid cooling too.

Liquid cooling systems can operate on either a simple convection principle or with a circulation pump, whereas a Freon system requires a compressor to function which exponentially increases cost, size, and complexity. So I kinda doubt that refrigerant based systems were ever used in any consumer electronics.

Anthony
PS Upon closer examination of that auction, you'll note the heatsink has what appears to be a tube going thru it, I suspect that this carried the liquid thru the heatsink and probably is alcohol based and works on convection.

qboneus
06-04-2004, 01:36 PM
Naw,
only R-11 and R-22 Have been banned in the United states.
They are still in production in Mexico and other countries that aren't as concerned by a products ODP (ozone depletion potential) as we are.
There are lots of "green" refrigerants still in production in the US , thats what all of our ac's and refrigerators and unit coolers, ect that are put out today utilize.

"freon" is a trade name utilized and registered to the dupont corporation the generic term is actually refrigerant.

Many poeple are under the incorrect assumption that because no more r-11 or r-12 are being produced that it is not used today....
That is totally wrong, it is just far, far more valuable than it was before banned.
I have a 30 lb jug of R-12 stored away- once it was $1 a lb last time I looked it was between $25-30 per lb.

MOST commercial climate control is still utilizing r-12 think tractor trailer/ Tractor/ Combine and pretty much autos produced before about the mid nineties.
Homes largely use R-12 or a new product callled "puron"which is a trade name as well.


I wouldn't be suprised in the least to find out that these heatsinks were once charged with some composition of refrigerant. It would be the best way to cool an heatsink evenly and I have wondered why it hasn't been done more other than the pressure/temperature relationship would cause the 'radiator' to rupture under high heat loads?

Why do you ask do I know this?
I am an EPA universally certified refrigeration technician and that is what my degree is in.
Whare do I work?
A high School as an AV/Computer technician????:dunno: :dunno:

Warmest wishes,
Tal

Ps refrigerant still has the same heat absorption properties even without the compressor it just can't undergo the rapid change of state without the compressor.

whitetrash
06-04-2004, 01:36 PM
Bolly,

I just have to ask, is that a stove you are using as a work bench?

DanTana
06-04-2004, 01:58 PM
Maybe if you left the stove off when you worked on that, it wouldn't get so hot? :) Seriously, liquid cooling has been around as long as the automobile so nothing ground shaking there, although implementing it into a stereo is somewhat rare. I would think a class A amp would benefit significantly from this. Be interesting project to try, only thing is a heat pipe would be more trouble free and no moving parts, plus lets not forget what kind of damage liquid can cause, unless of course you use non-conductive coolant. I don't have any equipment that gets that hot where I'd consider liquid cooling, then I think I'd consider fans before I'd go with liquid cooling. The Delta fan would be enough to cool even the hottest of equipment, although rather loud it has roughly 70cfm of airflow.

bolly
06-04-2004, 02:35 PM
whitetrash, Yes sometimes my workbech doubles as the kitchen stove...

heathkit tv
06-04-2004, 06:54 PM
Aha! Someone who knows the intricacies of refrigerants! Silly me was under the impression that Freon would need to go thru the expansion and compression cycles to extract the heat (for those who don't know, cooling systems don't "make cold" they just extract heat).

I know that Freon (R12 in particular) is widely available for very cheap in Mexico and that supposedly more of that is smuggled across the border than pot! Here in the US the outrageous price reflects both the rarity of it (warehousing costs) and a federal tax of some sort. Commercial service personnel need to be trained and certified to keep people from blasting it into the atmosphere. Jeez, I remember years ago using a can of it to cool off a choke to help adjust it! This was standard procedure in the car repair biz.

Nowadays when working on an older vehicle's A/C one must first check to see what flavor gas is actually in the system, it can be a multitude of Freon substitutes including, of all things, Propane!! Actually, except for the danger potential, Propane does a helluva job in cooling.

Anthony

BeatleFred
06-04-2004, 07:26 PM
Bolly- can you update on the status of that D11 you have?

I just bought a 2nd D11 for $50, its non-working- I recall you were ordering transistors for yours, and I'm wondering how you made out with getting those parts, are they exactly the same as the original transistors? I might need to get some for this one I just acquired, its not an urgent priority, but if you found the proper transistors and the price is reasonable, I'd then be inclined to order the same for myself at this time.

B/F

john_w
06-04-2004, 07:34 PM
Somebody brought one of those liquid cooled Sansui recievers into an electronics repair class at the local college I was attending. I got a good view of the cooling tube, and that memory reminds me a little of an air vortex cooling system I got to play with later on.

Yes, that's right - air vortex. Just start a moderate flow of air through it (I just used a bicycle hand pump), and the thing frosts on one end! One of the most bizzare things I've ever seen. It has a small adjustable valve at the smaller end, opposite the end close to where the air comes in, and a larger valve on the near end. If it's adjusted right, air first goes towards the small end close to the tube walls until it builds up pressure, then reverses direction and drops down the center. As it reverses, it swirls into a vortex, just like your sink drain. A vortex requires energy, so it pulls in heat energy from the tube walls, and then flushes it out the big end.

Of course, I kinda doubt that's what was in it. The big problem being how you would you create enough airflow in a compact stereo system. Lots of info on the web about those things, though. I just searched on "air vortex cooling" and got lots of hits.

BeatleFred
06-04-2004, 07:50 PM
Air vortex, well, as Mr. Spock would say, "Fascinating".

Just dont accidentally sit on one :butt1: :yikes:

bolly
06-04-2004, 07:51 PM
I did install Sanken's but they weren't the same. Supposedly they cross-referred... I installed them, she's still in protect. I'm moving next month and my new job will afford me the oppurtunity to work on my beasts there! Can't wait, they have all the goods!

Greg

Vintagaholic
06-04-2004, 09:02 PM
Great discussion.

Qboneus - I am also a MACS Certified AC Technician, degree in ME with an emphasis on heat transfer. I work for a major off-highway construction machine manufacturer. I was the point development guy leading the effort to convert all of the HVAC systems from R-12 to R134A. The world is now a safer place...if you ignore the fact that the PAG oils used with R-134A to lubricate the compressor will cause youre testicles to fall off if you are exposed to it too much. Then there is all of that ozone depleting cow flatulance that we haven't figured out how to control... Doesn't matter, now I am in marketing.

Anyway, I doubt that a commercial based refrigerant such as R12 could be used without a proper evaporative/compressive system. Peak heat transfer to the refrigerant occurs during the phase change from liquid to gas. Once the refrigerant is in a gaseous state, you would need a compressor and a condenser, respectively, to increase the pressure and reduce the temperature to allow the refrigerant to condense back to liquid to start the cycle over again.

Alchohol might work since it has a relatively low boiling point and exists as a liquid under standard atmospheric pressure and temperature. You'd still need cooling plates to take the heat out of the gas so that it would condense back to liquid again.

I really enjoyed the vortex info. I'm gonna study up on that one!

john_w
06-05-2004, 12:51 AM
Then there is all of that ozone depleting cow flatulance that we haven't figured out how to control...

Maybe copious amounts of Beano in the cattle feed?

I just toured the Coors brewery, and saw how they turn the used-up hops into cattle feed. Considering how I, ah..."process" some of my beer, no wonder we have an environmental problem!

heathkit tv
06-05-2004, 02:51 AM
Ah so, I have been somewhat vindicated concerning R12 requiring a compressor!

The deal with the Vortex thing, these are called Vortex tubes and are a cylindrical deal with 2 different diameter ends. Compressed air is introduced offset from the center and it blows out both ends. Hot on one with cold on the other. I've forgotten the physics behind it but they consume enormous amounts (CFM) of air at relatively high pressure. That's why they really are inefficient to use for HVAC although they come in handy for testing sensors or chokes etc on vehicles. A downside is that they're pretty noisy and eat a lot of energy (from the air source).

Nothing is for free. It's all about energy conversion and heat transfer. I sure ain't the one to figure all this stuff, just lemme beat it with a hammer and jam some epoxy in there and sent it out the door.

Anthony

qboneus
06-05-2004, 10:23 AM
I never claimed the cycle of typical cooling didn't require a compressor. Just that as a medium that would evenly distribute a large heatload, that a refrigerant might better equipped to dristribute a heatload evenly thru a given space than a pure aluminum heatsink.

I guess I didn't properly voice my musings.


I do not claim to be able to engineer these things... just knowledgeable enough to be dangerous!!


The question still remains... what in the world is in the tubes??
Alcohol??

Tal

bolly
06-05-2004, 11:05 AM
To the best of my knowledge, those heatpipes are empty!

Greg

EchoWars
06-05-2004, 08:12 PM
If it's empty, it ain't a heatpipe. ;) Air is a piss-poor conductor.

Why do you think it's empty? Unless you cut open the tube, how would you know? Heatpipes are not that uncommon, and by definition, heatpipes have a vapor change fluid of some sort (sodium, lithium, ammonia, methanol, refrigerant, etc..). Not enough that you'll hear it if you shake it around (the internal wick prevents it from 'sloshing).

heathkit tv
06-07-2004, 02:53 AM
I know what's inside that......................magical Fairy dust and Moon Beams.

To quote Jet Screamer (from the Jetsons) "It'sssss Space MAGIC!"

Anthony

john_w
06-07-2004, 03:40 PM
Any active cooling system, whether produced by condensation, air vortex, chemical reaction or cow flatulence (had to slip that in somehow), is probably going to be more effective but far less efficient to produce, run and maintain than just shoving good old fashioned "pig-iron" fins (or in the case of many modern electronics, cheap aluminum ones) into a strategic spot. Too bad -- overwhelming economic and practical issues win every time.

Some years back, an old college prof. of mine went to work at a new outfit that was producing some sort of chip - I think it was some kind of metal or bi-metal material - that transferred all of its heat energy from one side to the other when you applied electricity to it. I never heard anything about applying that technology to cooling systems in home electronics. In fact, I really don't know what became of the company, or that technology.

qboneus
06-07-2004, 04:24 PM
Yep!
One can go to wal-mart and witness the thermal-electric cooler..
It plugs into your 12volt lighter plug and can actually cool the contents.
Not very expensive either.
Pretty cool!:D
Tal

Raycomics
06-07-2004, 08:36 PM
I toured the Coors Plant in 1988!

The best part of the tour was where they let you "sample" the fresh brewed merchandise at the end of the tour.

Guys, there is nothing, I mean NOTHING like the taste of a Cold One fresh from the tap at the Brewery!

heathkit tv
06-07-2004, 09:26 PM
The chip you speak of is known as the Peltier Effect...similar in a proactive way to a good old thermocouple. Google it and you'll find tons of info.

Regarding the beer plant tour, at one time I had a girlfriend who worked at a local brewery.....took the tour and didn't tell her. While inside the plant I saw her and crept up behind her and said some vile things, she about hauled off to sock me and then saw it was me! LOL

Anthony

Vintagaholic
06-07-2004, 11:01 PM
Wow, I went on a beer tour too...snuck up on a girl and said vile things. The girl turned around, smiled at me and gave me her phone number. Heathkit...What did you say your girlfriends name was?? :D Kidding...

Free beer is great, but I didn't think Coors could ever taste good, no matter how fresh and cold it was. I'd have to suck it through a vortex so I wouldn't have to taste it. We called the vortex a "beer bong" in college.

Hey! Maybe there Coors in those cooling tubes???

john_w
06-08-2004, 11:52 AM
Hey! Maybe there Coors in those cooling tubes???

That would explain why they're now empty. I can see why that technology wouldn't last long: Coolant abuse!

Coors is alright for cheap American factory beer, but not exactly my favorite either. On the tour, you get three eight-ounce samples of any Coors product -- everything from Zima XXX to Coors Light. And since they're also a distributor of Molson, they throw that in as well -- for people who know what real beer is.

I've heard that the old Stroh's plant in Detroit (now assimilated into the Coors collective) used to have an "all you can drink for 40 minutes" policy. Now, THAT's a tour!!!

john_w
06-08-2004, 12:06 PM
NO offense meant to Raycomics. Stroh's wasn't exactly the ultimate in fine pilsner either! In fact, I'd favor Coors over Stroh's. It's all beer though, and fresher is better

Most people here actually drink Budweiser. A lot have switched to local brews. Fat Tire Ale from New Belgium Brewing Co. is all the rage now.

Now, what was the topic? Oh yeah, liquid cooling. OK, I guess we're still on-track.