| sss |
hey guys
what do u think of using cpu cooling fan and heatsink with a gainclones? will it be big enough? |
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| S.C |
| I don't think you will like the fan's noise when you enjoy your music.:dead: |
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| sss |
| i think cpu fans generate less noise then the fans in some power amps |
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| stadams |
| quote: | Originally posted by sss
hey guys
what do u think of using cpu cooling fan and heatsink with a gainclones? will it be big enough? |
It should work fine depending on the size of the sink and fan. Marshall amplifiers uses a TDA7294 @ 50 W in there MG series amplifiers and keeps it cool by the method that you describe. It would appear to be the size of a Pentium CPU with fins approximately an inch tall. An Athlon heat sink would be even better, although you may have to speed control the fans.
Later, |
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| Ropie |
I don't think you will need the fans, even in the desert temperatures ;)
Much better is to get a more solid heatsink with thicker fins, or no fins at all. CPU heatsink fins tend to ring, though there are ways to damp them. |
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| tg3 |
If you do want a fan, use a low noise model like this one.
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| sss |
| i'm thinking of using somthing cool like this ones |
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| AGGEMAM |
| quote: | Originally posted by tg3
If you do want a fan, use a low noise model like this one. |
Too noisy.
Choose a Papst fan, even the noisiest of those produce only 19 db(A). I use 3 of thier 9 db(A) coolers and even if put my head against the cabinet I can't hear them (during the day, in the middle of the night it's just about noticable). |
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| JAZZ2250 |
I've tried GC with CPU heatsinks and fans. The fans were not "silent-grade" like the ones in the picture and I couldn't stand the noise. However, when I lowered the power supply voltage for the fans to let them run at lower speed, they became very quite. So, if you use "silent-grade" fans at slightly lower than the rated voltage, you will hardly hear the fan noise. But, you cannot lower the power supply voltage too low because fans need minimal amount of voltage (and current) to operate.
Good luck.
Jai |
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| AGGEMAM |
| Very true Jazz, around 8 volts is minimum. But the primeary concern is a good silent fan, so waht if they cost $3 extra that is money well spent. |
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| 5th element |
Thermal Take NONONONONO!!!
We have one of those VERY VERY noisy not good for that, but is does have VERY good cooling for an overclocker. TT are actually not cheap, why not just buy a heatsink. |
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| S.C |
| http://www.diyaudio.com/forums/attachment.php?s=&postid=341988 In have a thought with this one. You can buy this and make your chassis cover that will let the heatsink explose out of the air. Then take off the fan, and put a cup of ice on the top. Prefect, you got water cooling. And a cup of hot water haha.:eek: |
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| ronc |
IMHO a fan cooled HS is kinda a waste of money and effort. I just use a large heavy(.5-1.5 lb) gold plated brass bar. It gets lots of mass isolation as well as a HS action.Alhough my next design is using the bar with a finned normal HS thermally and mechanically connected.
ron |
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| matjans |
| why not just use any old left-over processor heatsink without a fan? Anything from a pentium HS and upwards should have enough capacity to cool an lm3875. |
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| Variac |
Matjans: correct
S.C. Just the fins without the cup of ice would be fine (and look very very cool) |
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| sss |
| quote: | Originally posted by matjans
why not just use any old left-over processor heatsink without a fan? Anything from a pentium HS and upwards should have enough capacity to cool an lm3875. |
i dont think that this will be enough |
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| S.C |
| My P III Heatsink got pretty hot in summer with my 330VA 25+25V Tansformer. The heatsink still warm in the coolest day in US.:angel: |
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| moses |
| Those Zalmans while expensive would probably offer the best cooling, possibly even passive. Likewise you could make a rather neat looking chassis by leaving them exposed(whether using the old style Zalmans or the newer radial ones). |
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| sss |
heres another idea
we can throw the entire amp into a glass of distilled water :bigeyes: (distilled water shouldnt conduct electricity right?) |
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| matjans |
too dangerous...
you'd be better of using hydrofluorether (fluorinert); for more info click this link... |
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| Nuuk |
| quote: | | i dont think that this will be enough |
It's not quite as warm here in the UK but I find that PC heatsinks, one for each chip, and used properly (ie using conduction) work fine.
The amp below uses 37 volt rails and the heatsinks never get above luke warm. The heatsinks sit over circular apertures in the base plate so that air is drawn up and expelled through the apertures in the lid.
There is nothing stopping you adding an extra piece of aluminium to the heatsink if you think that you may require more cooling. ;) |
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| etal |
I was thinking of using passive cpu heatsinks as well but found out that its not a very good idea.
CPU heatsinks were designed for active cooling so they have very little spacing between the fins and rely on a high airflow to move the heat away quickly. This design has very bad performance with passive cooling and no airflow. |
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| Nuuk |
| quote: | | CPU heatsinks were designed for active cooling so they have very little spacing between the fins and rely on a high airflow to move the heat away quickly. This design has very bad performance with passive cooling and no airflow. |
Etal, often theory and practise do not agree as we would expect and in such cases experimentation is more useful than theory! ;) |
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| sss |
| quote: | Originally posted by matjans
too dangerous...
you'd be better of using hydrofluorether (fluorinert); for more info click this link... |
why is it dangerous? |
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| bigparsnip |
| IF you want a cheep heatsink for your gain clone, just go on ebay and have a look about for old pentium II/III type heatsinks without the fan. I picked up some decent foxcon ones for my project and they seem to work great (although the thing still ahsn't been powered up propperly as I need more tools to finish off the case) |
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| matjans |
| quote: | | why is it dangerous? |
the slightest contamination of the distilled water will change its dielectric properties and i wouldn't want that.
iow, you can say :wave: to your clone...
There's recently been a thread about this, can't seem to find it but if you search a little harder than i did you probably will. |
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| lgreen |
Llike bigparnsip, I've got the computer heatsinks going. I'm using small brass bars to push the chip onto them for max thermal xfer. With 35V rails it barely gets hot in normal operation.
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| w00t |
| quote: | Originally posted by matjans
too dangerous...
you'd be better of using hydrofluorether (fluorinert); for more info click this link... |
I've got 5 litres of that stuff from my friend. I heard it costs a few K for a useful volume of Fluorinent. :hot: :bigeyes: |
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| groggory |
| Pentium 4 stock heatsinks are wonderful. Designed to dissipate 85W of heat, near silent, and easy to mount. All you need to do is design your PCB with the 4 mounting holes. Go to a local computer shop and see if you can get dead motherboards. Take the P4 bracket off to use. And whalla, you have a wonderful HS. |
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