[oddity]

Before you go any further, please watch this: http://www.youtube.com/watch?v=tHHk7fB_h1Q
 
What an interesting concept! I know that the big power transformers mounted on power polls use mineral oil submersion as a method of cooling and protecting them, but I had never considered using it on an electronics scale. 
 
I think that this sort of cooling, in addition to looking really cool, would be of great benefit to vacuum tubes. The oil be a great aid in keeping gases from getting into the tube, as well as keeping them cool.
 
It would also be very interesting to see it used in solid state cooling as well.
 
Would anyone else be interested in in building an oil submerged headphone amplifier? If you would be interested in a group design effort, please let me know.  

 

[oddity]

Ok, even if you have no interest in building something like this whatsoever:
 
1) Do you think that there could be any adverse effects on audio circuits by submerging them in mineral oil?
 
2) Is this just a waste of time? 
 
3) Has anyone done this already?

 

[bcg27]

1. No
 
2. Yes
 
3. I have only seen it done with computers
 
It seems like it makes quite a mess so good luck if you ever want to change a part. Most audio stuff is fine with passive air cooling, if you submerge it in oil you need a pump, radiator, etc. 

 

[oddity]

It seems like a typical DC cooling fan is enough to circulate the oil in the enclosure. I still think that the oil would go a long way in extending the life of a tube. No ambient gasses = No gas leaks into the tube. Right?

 

[nikongod]

How long does it take for a tube to loose vacuum? if you say 40 years, I'l point to some 60+ year old tubes that still function. If you say you have a tube that sucked air within a few years I'l point you to a factory that dosnt/didnt have their QC down as well as sylvania did in 1960.
 
Anyways, its not a problem. Tubes rarely go leaky and when they do you just replace them.
 
If the tube does go leaky and is submerged you have an oil leak rather than a gas leak... Vacuum will suck anything through a crack. If Vacuum tubes worked when filled with oil, wouldn't the original designers just fill the bottles with oil? Its a LOT easier to fill a bottle with oil than to get the vacuum contained.
 
If you are concerned with tube life as a function of heat run your tubes at an operating point that respects all published (and reasonably assumed/read between the lines in some cases) limits on power, voltage, etc. It may be surprising to hear that this works at all, but I assure you that people have been designing tube amplifiers that respect all published limits of power, current, voltage, and the like for nearly 100 years! 

 

[oddity]

I hadn't thought about a tube flooding with oil, with out a doubt that would seriously screw up the process of thermionic emission.
 
That being said...
 
I am going to go through with this. My plan is to build a high voltage (120-300+ ) dual regulated DC power supply for bench testing purposes. I need a power supply for tube testing anyway, so why not go for broke and build something ridiculous? Since it is going to look like it's under water, I'm going to call it The Poseidon (POintlessly Silly minEral Oil-cooled Dc pOwer Node).
 
Does anyone know of a high-voltage DC power supply schematic that has:
 
1) At least 120vdc capability, preferably with more voltage than that?
2) Is variable?
3) Is solid state?
 
Yeah I know it's silly as two-bob watch, but one has to go a little nuts every now and again. Right?

 

[bcg27]

Quote:

I hadn't thought about a tube flooding with oil, with out a doubt that would seriously screw up the process of thermionic emission.
 
That being said...
 
I am going to go through with this. My plan is to build a high voltage (120-300+ ) dual regulated DC power supply for bench testing purposes. I need a power supply for tube testing anyway, so why not go for broke and build something ridiculous? Since it is going to look like it's under water, I'm going to call it The Poseidon (POintlessly Silly minEral Oil-cooled Dc pOwer Node).
 
Does anyone know of a high-voltage DC power supply schematic that has:
 
1) At least 120vdc capability, preferably with more voltage than that?
2) Is variable?
3) Is solid state?
 
Yeah I know it's silly as two-bob watch, but one has to go a little nuts every now and again. Right?

Solid state is definitely a better application for oil submersion than tubes I think. I will reiterate my recommendation to use a pump to move the oil through a radiator as I am doubtful that a regular 12V fan will function well or for very long submerged in oil. Also, simply circulating the oil in a closed container does no good without good heat sinking to the outside world...

 

[Uncle Erik]

I've also seen tubes last for 60+ years without a leak.

One problem with oil-cooling tubes is that the oil would leak through the tube sockets. You'd have to have the entire amp submerged in oil. That would be a problem with sockets and switches. You'd have oil leaking out through the amp unless you used waterproof bits and carefully sealed the amp. It would be a complete pain and I don't see what the benefit would be.

Air-cooling tubes works fine and has for nearly 100 years. Oil would cool them, but it'd add an unnecessary layer of engineering and expense.

 

[Rockhouse]

HI all.  New to the forum and just have a quick question.  I have a stereo receiver that I am using to provide sound to a little cafe that I own and it hits an "amp protect" state.  What I've read, it seems to be overheating.  SO I am considering for functionality coupled with form, dropping my receiver in a nicely designed custom glass enclosure filled with mineral oil and a fan for circulation and aluminum fins from the oil to the air to act as a heat sink.  Anyways, that is just background.....can I drop a receiver in mineral oil?  That's the gist of it.  Thanks guys and ladies.

 

[WNBC]

X2.  I thought sometimes using a small fan to keep the amp cool if I was burning-in components overnight was overkill on my part with my Schiit Lyr 

.  
 
Quote:

I've also seen tubes last for 60+ years without a leak.

One problem with oil-cooling tubes is that the oil would leak through the tube sockets. You'd have to have the entire amp submerged in oil. That would be a problem with sockets and switches. You'd have oil leaking out through the amp unless you used waterproof bits and carefully sealed the amp. It would be a complete pain and I don't see what the benefit would be.

Air-cooling tubes works fine and has for nearly 100 years. Oil would cool them, but it'd add an unnecessary layer of engineering and expense.

 

 

[samsquanch]

Quote:

HI all.  New to the forum and just have a quick question.  I have a stereo receiver that I am using to provide sound to a little cafe that I own and it hits an "amp protect" state.  What I've read, it seems to be overheating.  SO I am considering for functionality coupled with form, dropping my receiver in a nicely designed custom glass enclosure filled with mineral oil and a fan for circulation and aluminum fins from the oil to the air to act as a heat sink.  Anyways, that is just background.....can I drop a receiver in mineral oil?  That's the gist of it.  Thanks guys and ladies.

 
Your issue seems goes beyond it overheating, what kind of load are you driving with your amp?  What is your amp?  What are your speakers?  Most home theater receivers can't handle much below a 4 ohm load, are you running several speakers off of one output?  
 
Dropping your stereo in a mineral oil bath might solve your heat issue, but if not, then not only do you have an over loaded amp, but a slimy one as well.

 

[samsquanch]

Also, in regard to the original question, go here:  http://en.wikipedia.org/wiki/Johnson%E2%80%93Nyquist_noise
 
If you can prove that the components inside your gear are generating audible noise at their operating temperature, that could be eliminated, if they were reduced to at least ambient room temperature, then sure go crazy, use liquid nitrogen!  But you'll probably find that everything is working just fine.

 

[Rockhouse]

Samsquanch aka Steve French....The receiver is the Harmon Kardon HK3490 and it is powering two pairs of Yamaha NS-AW350W.  From the sub out on the back, it runs to a Bash 500s (a truly amazing and durable little amp).  This in turn powers a MTX audio tr75 (15" sub).  But I think all of this may be moot as we found some random speaker wire (I think an employee was messing with something) that was connecting to itself and seemed to be what was causing the "amp protect" to come on.  But, for pure novelty and such, I am still considering dropping the rig into a nicely made custom tank and having it as a sort of piece of art in the restaurant.  Thanks for any input.

 

[BrianDonegan]

Two additional things to think about with oil cooling...
 
1) You still need heatsinks on the enclosure to cool the oil.  It will absorb the heat, and eventually get up to the same temp as the parts you are trying to cool... it needs to go somewhere.  Oil (or water in a car) is used as a thermal conductor to get the heat from the hot thing to the thing that can get rid of the heat (heatsink or radiator).
 
2) By submerging all the electronics in oil, you are making the hot parts cooler, but the cool parts hotter, possibly hotter than they are designed to operate.