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Educating Myself About Fan Noise

Until I owned a Dynaco 400 (200 WPC) Vintage Solid State Amp, I don't think I had ever given this issue any thought.

If I unhook the fan, it does get a bit too hot, so I have to plug it back in. I've had some recommendations to try quieter fans, but I am very do-it-yourself averse, and I am very extraneous-noise averse, so I am thinking of simply trying to buy a new two-channel amp.

Putting aside all the other issues we could discuss (what is my system, budget, etc.), I think my interest here is just really to understand a bit better an issue that I'd never really given much thought to. Do many amps, tube or solid state, have this fan noise issue once they get "up there" in power?

I do think I would like good power for this particular speaker setup and am leaning toward solid state. I'm fine buying some less expensive "decent" sounding equipment, but when I read about it I don't know if the owners are putting up with fan noise and not even telling me.

I guess I just would like to narrow down, when I read about some of that equipment, how much of it has this fan noise that it brings with it.

I have a 70 WPC Arcam integrated amp that I use in another purpose, and this allows me to hear some good things (I've never owned a lot of super-duper hi-fi, though my speakers are considered good), even if it's not super-powerful, and it does not have a fan, but rather some modest-sized heat distribution in the back.
joshl
jedinite24's avatar
jedinite24
1,503 posts
 
Greetings. Here is an update. It's been quite a learning experience with this fan and the amp.

First the fan currently in the Sumo 9 of mine is:

NMB - 3110MS-12W-B30-A00 - Axial Fan
Manufacturer: NMB
Newark Part Number: 34R2249
Manufacturer Part No: 3110MS-12W-B30-A00 RoHS Compliance :

Description Axial Fan
External Height:80mm
External Width:80mm
External Depth:25mm
Current Type:AC
Supply Voltage:115V
Fan Flow Rate:24CFM
Noise Rating:31dBA
Bearing Style:Ball
Power Connection Type:Lead Wires
Current Rating:90mA

This is an AC fan that runs full speed all the time. There is no drop in replacement from the sites I checked that could still push out around 24 CFM and have a db level less than 31dBA.

Srwooten. I took some rubber spacers I had and cut them and put them on the corners of each fan. This seperated the fan from the metal surface of the Sumo 9. This all but elminated the vibration noise caused by the fan. It was my biggest gain in decreasing the noise.

Now to Shadorne's post.

I haven't had much luck with PS3 coolers in general. They were temp controlled but when they came on they were loud to my ears and audible from my sitting distance. From looking @ the Neeko or Nikko fan I have with my PS3 it looks like a bunch of noisy 40mm fans. If you could send me any leads on low noise AC fans that you have used in the past I'm game. The only 80mm fan I found that could move more than 24cfm but have less than 31 dBA was from Noctua. I would have to mount this fan externally from the Sumo and power it seperately with an AC adapter since it is a DC fan. Really ugly.

Thanks for the lead on the projector. My uncle is in the market for a new one. I'd love to take it apart to see how the fan system works but my uncle would kill me.

Now I did apply some Acoustipack panels to the internals of the Sumo 9 and it helped marginally. I'm going to enjoy the amp for now and figure out what kind of enclosure I'm going to build around it.

Thanks
cajunpepe
255 posts
 
i passed on buying an ARC Ref 110 due to fan noise.
johnanguswebb
7 posts
 
Eight years after the posts above, I want to thank jedinite24 for documenting so much information about the fan. I just bought a Sumo 9 without a prior listening test. The fan was definitely an issue. Having read it should be making 31dB of noise, I measured mine at 56dB. I think it may be getting old! Even a relatively loud new fan should be an improvement. It’s good to know the required specification while I look for one.
Thanks again.
PS my immediate solution to the fan noise problem was to put the amp in the basement, run speaker wires via the heating duct cutouts, and turn the amp on and off remotely using Google Home with a wifi smart plug. Despite that, my fan is actually so loud I can hear it faintly through the basement door. I think I’ll also add rubber grommets as suggested above. Thanks for that tip too.
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