Hartke KB15 fan noise.

[6thplanet]

My Hartke HA7000's fan is what I would consider loud. I also have a 2500 that I was using as a practice amp, it too was quite annoyingly loud. I installed a switch on that one to shut it off since it never leaves the house.

I find class D amplification is so much more efficient that they need a lot less cooling compared to their AB counterparts. The problem is how they are packaged. With the advent of how compact everyone wants them to be, heatsink area is reduced, hence needing a fan. Depending on how that is implemented, you might end up with a loud or noisey fan. As Agedhorse has commented, it's all about HOW it's implemented.

 

[tshapiro]

My Hartke HA7000's fan is what I would consider loud. I also have a 2500 that I was using as a practice amp, it too was quite annoyingly loud. I installed a switch on that one to shut it off since it never leaves the house.

I find class D amplification is so much more efficient that they need a lot less cooling compared to their AB counterparts. The problem is how they are packaged. With the advent of how compact everyone wants them to be, heatsink area is reduced, hence needing a fan. Depending on how that is implemented, you might end up with a loud or noisey fan. As Agedhorse has commented, it's all about HOW it's implemented.

That's a good point. The Class D's I've seen are in very small and portable casings. My Class A/B housings are 4x-6x bigger.

 

[agedhorse]

Also, don't modify or shut off the fan in any amp. Some designs require that the fan is always running at a minimum speed.

 

[beans-on-toast]

A classy amp shouldn't be noisy.

In this application note, they mention that too much heatsink compound is not good. I see some amps where they apply a thick layer of compound. Active heatsinks with integrated fans are used in some industries.

https://www.hypex.nl/media/b8/33/ac/1686146768/AN_Thermal_design.pdf

Poor heat transfer can make a fan run faster.

 

[6thplanet]

I see that a lot with DIY builds and amateur repairs. Heatsink compound is not really thermally conducive, like the heatsink the components are being attached to. It's meant to fill in the minor imperfections of the heatsink because it's more conducive than air.

 

[BES-BASS]

At Sweetwater, there's a 1-star review by "Russell A. from Dallas" that implies the fan powers on only when the amp warms up.

https://www.sweetwater.com/store/detail/KB15--hartke-kb15-kickback-500w-1x15-inch-bass-combo/reviews?stars=1

Thank you! The amplifier is ok. I used it for a long time and the fan turned on.

 

[agedhorse]

It's so much better when you don't attempt to fix a problem that doesn't exist.