What were Trace thinking of?

[Colledge]

how would you re-design the cooling system?
the fan is no big deal for me but theres no harm in improving it.
i'm getting the aluminium for a new headcase bent for me this week, i'm thinking of adding a few slots above the heatsinks to get a bit of convection cooling / extra air output and then have an inline pot for fan speed so i could turn it off for quiet practice / recording? good or bad idea?

[stevie]

If you're willing to put in the time and effort, I'd suggest creating a decent vent area somewhere near the front of the case - probably on the top or at either side of the front panel. Then turn the fan round and have it pulling air in from the front and venting through the back. Block up any other vents at the back to prevent short circuits. Even with a slow, quiet fan you can pull half a cubic metre of cold air a minute across the heat sink to cool it down, which should be more than enough as the Trace heat sink is quite decent.

Papst do temperature controlled fans with a sensor that could attach to the amp's heat sink. I think they cost about ten to twelve pounds. The temperature control would then be automatic rather than via a pot. You might need to experiment with this arrangement, but temperature controlled would definitely be the ultimate, as the fan would only need to get up to speed when you're hammering the amp. The rest of the time it would just be idling and would be inaudible.

And I'd definitely install the silicon spacers as I described in my earlier post. A quid well spent IMO.

[Fraktal]

Have you ever tried Noctua fans? I am a freak when it comes to silence and my computer has a total of 5 Noctua fans inside. It is my DAW, so it HAS to be really quiet. It also gets very hot, happens when you abuse of CPU heavy audio plugins inside a 3 layer plastic computer case for acoustic isolation. 1 fan for intake, 2 for exhaust, 1 for CPU heatsink and the last one for the power supply. I tried almost every brand out there (including PAPST, of course) and Noctua were the quietest ones by far. It was not so evident comparing 1vs1, but the sound of 5 fans at the same time was obviously louder, making it much easier to pick up a winner.

Sitting 50cm away with my computer on the table I need 3AM countryside silence to notice a very quiet whoosh of air coming from it. Try them if you ever have the chance. They are anything but cheap, worth every penny, though.

[ahpook]

[quote name='Spoombung' post='947732' date='Sep 6 2010, 10:27 PM']Fans in amps are one of my pet hates. And they get noisier and noisier the older they get[/quote]

with you on that - i don't run any amps in my practise room with fans...eventually they drive me mad.

the fan in my gp7 150w head was quite noisy.

[daz]

Dont know about this amp, but i used to build computers, so i know that the air circulation is worked out very carefully in these type of small boxed elctrical goods, which can get very hot. Cubic feet of air per minute is measured at different temperatures, and some fans are built to speed up if the temp rises. The route the air takes, both being sucked in (which some forget about) and being blown out is not an afterthought. There may even be more than a single fan. This will really complicate the cooling process and the route that the differeing temperature air takes as it moves inside the box.

I would be [i]extremely wary indeed [/i]about closing up any vents. There are some computer fans out there that move more air, and some that are very quiet. Not sure if you can have your cake and eat it though. If you want to go the quiet route then try this one. (i have no affiliation)[url="http://www.acoustiproducts.com/en/acoustifan.asp"] accoustifans[/url] You need to find what rate of air per minute the current fan exhausts, then be sure the fan you get is equal to it. Not to mention making sure power consumption is within acceptable limits.

Remember even pointing an ill thought out cooling fan at an amp can do the opposite of what its intended for and cause it to overheat, if its blowing the vented air back inside the box ?! The only surefire way of cooling an amp down is to lower the ambient temperature.

PS: remember the noisy 'fan' could actually be noisy bearings.

Edited September 19, 2010 by daz

[Mottlefeeder]

[quote name='stevie' post='955289' date='Sep 13 2010, 07:52 PM']If you're willing to put in the time and effort, I'd suggest creating a decent vent area somewhere near the front of the case - probably on the top or at either side of the front panel. Then turn the fan round and have it pulling air in from the front and venting through the back. Block up any other vents at the back to prevent short circuits...[/quote]
Don't try and pull the air - push it.

Think of a desk fan - you stand in front of it, you feel the draft. You stand behind it, you don't.

'Blocking up any other vents' means sealant on every join, tape over every jack socket, etc. and even then you cannot be sure that the air from 'somewhere near the front of the housing' will flow over the heatsink on its way to the fan.

David