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DC Cooling Fans for Vintage Tube Amps

The distance between the fan blades and the cage, or other surfaces makes a significant difference as well. Just try listening to the sound when you get your hand close to the blades on either side of the fan. The less obstructions close by the quieter the fan will be.
 
My middling-fi, HT receiver is pushing 5 ohm speakers for the rear surrounds... so I rigged up a cooling fan to plug into one of the receiver's switched usb ports (put the cooling fan on top to suck the heat out). Running at less than half the rated voltage, this fan is dead quiet. Receiver doesn't even get noticeably warm.

https://www.amazon.com/gp/product/B0043GMR80/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I'll likely rig up a smaller fan to vent the power tube section of my V-M 1428.
 
I installed a DC fan in the shelf. Will have a filter when I finish. Might try batt power next.
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He said he wants them to plug into a power strip,120v. I did this once by adding a power resistor in series with the fan, plus, I mounted it so the fan draws cool air across it. It's not elegant but it works well. Was using it as a fan to cool ME off , BTW !
 
Bradbrews said:
The distance between the fan blades and the cage, or other surfaces makes a significant difference as well. Just try listening to the sound when you get your hand close to the blades on either side of the fan. The less obstructions close by the quieter the fan will be.
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Very true. But this is because the fan is not optimally installed.

Fans are generally better on pull than push, and obstructions reduce airflow and create greater noise. The design of the fan blade has a lot to do with this. So the fan should generally pull air through the unit, venting to open space, instead of trying to force air through the unit. This works for window fans as well, which is why air filters are generally placed on the intake instead of the exhaust.

I have a computer case with a front-mounted—by the case manufacturer, not me—200 mm computer fan to push air air over the (front-facing) disk drives and through the unit, through the peripheral cards, and exiting via rear holes. (It also had a side-mounted 300 mm fan which hits my humongous graphics card, so that had to be removed.) As more drives and cards were added, the blockage naturally reduced the desired airflow over the drives. When I added small (120 mm) rear and top exhaust fans to pull air from the interior and vent outside, thereby reducing interior cabinet pressure, the front fan became much quieter, moved more air, and the airflow became smoother.
 
jwrosenthal said:
I did a pair of 12v fans and cut and spliced a 12v wart from a junk bin with appropriate power rating for both (think they were 400ma and I used an 800ma Wall wart). Never occurred to me to use a 6v to slow it down (800ma+ I assume as well)- very clever idea. They do run at full tilt and sound like your running a fan in the room-go figure!
The fans really do work. I have an ARC D51 that gets smoldering hot (they were known to cook the caps in the first few years), and with the fans laying on top of the cage, I can put my hand on it and it’s only slightly warmer than room temp.
One point to note- isolate them someway. At first I thought the fans were really noisy and it was a deal breaker- but then realized as I moved them while they were running, that they were vibrating the cage. A set of stick-on rubber bottomed feet took care of that.

Also, those plastic blades can draw blood- on both thumbs!
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I have the same setup but rarely do I need to use them and then it's so loud you'll never hear a fan LMAO!!!
 
Here's what I did after re-capping my V-M 1428:

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I can't remember what I pulled the cooling fan out of, but it's a 12v unit. It's powered by a random 12v wall wart plugged into a switched outlet on the back of the amp. Dead quiet.
 
nmwhitneyjr said:
Here's what I did after re-capping my V-M 1428:

27396493547_c907e717f0_b.jpg


27396493437_57aedd8e25_b.jpg


I can't remember what I pulled the cooling fan out of, but it's a 12v unit. It's powered by a random 12v wall wart plugged into a switched outlet on the back of the amp. Dead quiet.
Click to expand...
That’s a very clever solution, you created a little heat shield and air guide.
 
I can't take too much credit... it was originally designed with a cardboard, 3-sided shield wrapped in tin foil. This shield on my amp was long gone.

I would have preferred to have the fan on the other end sucking instead of blowing, but I would have had to remove the speaker connections. I just didn't feel like doing that.
 
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