Heat Sink vs Fan?

[Undertone]

Hi.

Do we generally feel fan cooling is "better" than heat sink cooling at the back of solid state amp heads?

Fans obviously an additional moving part that can malfunction, and can generate noise, whereas head sinks are silent and stationary.  Let's assume the fan is sufficiently quiet for the moment.

Do we feel Fans are more or less effective at cooling vs heat sinks?

What other issues do I need to consider?

The main context here is in fact a 90's Trace Elliot SMX 300W head.

Thanks!

[alexclaber]

4 minutes ago, Undertone said:

Do we generally feel fan cooling is "better" than heat sink cooling at the back of solid state amp heads?

I don't think you need to think about this unless you're designing a bass amp - or looking to buy an old one that has a bad reputation for shutting down on loud gigs (there must be some but I can't think of one!)

You need a much bigger heatsink with passive cooling vs forced air cooling. Most amps with fans will have heatsinks too, just the fan allows the heatsink to be smaller, light and cheaper.

[Sparky Mark]

Fans can add audible noise if they run when you are playing at low practice levels; some are noisier than others and can be intrusive. Dust is also sucked into the amp by fans; I have 35 year old natural convection cooled Trace Elliot heads that are completely clean inside. Unless I was running a natural convection cooled head near to its max output in a warm environment for long periods I wouldn't be concerned. 

[Cuzzie]

Agreed with above - some of it will come down to the size of head you want - my solid state doesn’t have a fan - but it’s ‘big’ for today’s size at 2U rack size.

Its got loads of space inside to keep it cool, but I love the sound so it’s a no brainer.

[fretmeister]

I hate fan noise even at levels a bat wouldn't hear. At a gig I can cope - but in the house it drives me insane.

[grandad]

Fan in my TCE BH250 seems silent to me. Similarly fans in Yamaha and EMX5012 mixer & DXR10s also silent.

Any noisey fan would have to go.

P.S. My hearing ain't what it used to be though.

[ahpook]

53 minutes ago, fretmeister said:

I hate fan noise even at levels a bat wouldn't hear. At a gig I can cope - but in the house it drives me insane.

Yep, me too. I can't abide them.

 

[Undertone]

Many thanks for the replies people - helpful.

Regards

[agedhorse]

As power levels increase and size decreases, fan cooling becomes more and more necessary. This is something that the pro audio industry has dealt with for decades. There are good implementations with fans and poor implementations with fans, noise level being the most objectionable issues.

Fan cooled amps do not need to be noisy.

[Skybone]

19 hours ago, ahpook said:

Yep, me too. I can't abide them.

 

Bats or the fans?

[Bill Fitzmaurice]

If you can hear the fan you're not playing loud enough!

[fretmeister]

4 minutes ago, Bill Fitzmaurice said:

If you can hear the fan you're not playing loud enough!

I have great sympathy with this despite me personally hating fan noise completely.

But sometimes I'm accompanying only a single clarinet or flute and on some amps the fan noise is obvious.

[Sparky Mark]

Noisiest fan I've ever had was in my mid 90s Hartke AH3500. Never bothered me because that's all I was used to (and it's still going strong). Back then gear was big, heavy, noisy (mostly ugly too) and real men played bass; nowadays I'm not so sure. 😁

[fleabag]

Any non-weird size  noisy fan can be replaced by purchasing a replacement from these peeps below.  I've done this on a few occasions over the years

https://www.quietpc.com/casefans

 

 

[agedhorse]

8 hours ago, fleabag said:

Any non-weird size  noisy fan can be replaced by purchasing a replacement from these peeps below.  I've done this on a few occasions over the years

https://www.quietpc.com/casefans

 

 

Beware that the fan's voltage, current, CFM and static pressure ratings need to be very close on any fan that uses feedback speed control. These parameters are an important part of how well the fan speed tracks temperature. 

It's possible to really screw things up by focusing on the quietest fan, resulting in an amp that will either shut down (if you are lucky) or fail (if you are unlucky).

[ahpook]

On 20/08/2020 at 12:51, Bill Fitzmaurice said:

If you can hear the fan you're not playing loud enough!

 Not always a realistic approach for home practice when one is concerned about not annoying neighbours, which is when I find fan noise most distracting.

 

Edited August 22, 2020 by ahpook

[fleabag]

7 hours ago, agedhorse said:

Beware that the fan's voltage, current, CFM and static pressure ratings need to be very close on any fan that uses feedback speed control. These parameters are an important part of how well the fan speed tracks temperature. 

It's possible to really screw things up by focusing on the quietest fan, resulting in an amp that will either shut down (if you are lucky) or fail (if you are unlucky).

Yup, i would assume people would check the parameters first

[Woodwind]

4 hours ago, ahpook said:

 Not always a realistic approach for home practice when one is concerned about not annoying neighbours, which is when I find fan noise most distracting.

 

or playing in an acoustic environment, just like @fretmeister says.

 

I can't use amps with fans at all as even near silent ones become noticeable in resonant spaces.

Edited August 22, 2020 by Woodwind

[Dood]

On 20/08/2020 at 12:51, Bill Fitzmaurice said:

If you can hear the fan you're not playing loud enough!

And: If you can hear the fan, your amplifier is way over-powered for your needs* 😁

 

*Yes I get it, lots of people use their gigging amp for practice too, hence the smiley. 

[PaulWarning]

I've got a couple of Trace Elliot's both with heat sinks, some models have fans, prefer the heat sinks, no noise and less to go wrong, and bizarrely,  they seem to weigh less

[ahpook]

3 hours ago, PaulWarning said:

I've got a couple of Trace Elliot's both with heat sinks, some models have fans, prefer the heat sinks, no noise and less to go wrong, and bizarrely,  they seem to weigh less

Yes, I have a TE head with no fan for just this reason.

Aside from older stuff like this, are there any modern heads that are fanless ?

 

[Cuzzie]

1 minute ago, ahpook said:

Yes, I have a TE head with no fan for just this reason.

Aside from older stuff like this, are there any modern heads that are fanless ?

 

How old is old?

or how modern?

Edited August 22, 2020 by Cuzzie

[ahpook]

1 minute ago, Cuzzie said:

How old is old?

or how modern?

Use your own judgement.

[PaulWarning]

I don't think my Fender Rumble 500 had a fan, if it did it was noiseless

[Cuzzie]

46 minutes ago, ahpook said:

Use your own judgement.

Ok - my solid state with no fan came out in 2015, it’s discontinued now (not for any reliability of issues of it being rubbish) - I would call that modern - but it is a 2U rack size