Fan noise on Nady amps

[PoorboyMike]

Ok, I've searched the entire net, and I still didn't find the answer to my question. The fans on my Nady 1100 are standard 80mm 12volt fans with 2 pin molex connectors. I haven't actually pulled the top of my amp yet, this is just the info I got from one of the forums. Anyway, I've been able to locate quieter fans for good prices, but all of them have either 3 or 4 pin connectors.

So, what do I need to do to connect the quiet 3 pin fans to my 2 pin plug? I'm assuming I just use the hot and ground wires from the new fan, but what is the 3rd wire for? Can I just eliminate this?

[ThomasW]

Ok, I've searched the entire net

Wow that's a massive undertaking .....

2 pin connectors are 12volt only fans. Black is ground, red is +12V. More pins are related to lowering the voltage = speed control, and software/BIOS triggering.

http://www.silentpcreview.com/article63-page1.html

[PoorboyMike]

Wow that's a massive undertaking .....

It certainly was. And somehow I managed to miss the article you posted. Odd.....

Anyway, it looks like I can unplug the power to one of the fans and wire them in series and get 6 volts to both of them. Seems simple enough for most people but I'm not most people. Would I just splice both red leads from the fans into one of the connectors then do the same with the ground?

[ThomasW]

Buy 2 low noise replacement fans. Cut the leads off the old fans and wire the new ones normally.

[PoorboyMike]

Buy 2 low noise replacement fans. Cut the leads off the old fans and wire the new ones normally.

lol....why does that seem so easy? I think I was trying to make it hard.

But what about the speed control (3rd wire) on every low noise fan I've found? Just leave that disconected and it will work fine?

Sorry for the dumb questions.

[Cowanrg]

yes. a fan only needs the two leads to run. the third is just a bonus.

it is easy becaues fans collect dust in their innards, and it makes them unbalanced, or whatever, and it gets noisy. moving parts dont last forever.

[PoorboyMike]

OK, thanks Cowanrg.

Just for kicks though, I want to try the series wiring with the 2 I have to see if they will run with 6 volts. I see I had it wrong in my other question. Would you basically wire them the same way as you would 2 speakers in series? In other words, disconect both fans and use one of the 12v power supplies for both. Red wire to red wire on 1st fan, black wire to black wire on 2nd fan, and black wire from 1st fan to red wire on 2nd fan. Is this correct?

[hayden]

Here is a cheap, solid fan for you.

http://store.yahoo.com/pctekonline/8cmcasefan.html

I've used the 120mm version in pro amps and they are as quiet as any fan I've ever heard (including Silenx and Panaflo).
JP

[oneoldude]

If you can't get it quiet enough, you might want to isolate the fan from the chassis by using grommets in the chassis holes (might have to open up the holes) and sealing the created gap with weather stripping. You might also use nylon nuts and bolts. This will reduce chassis borne vibrations quite a bit.

You can also use a resistor in series with the B+ for each fan. This will slow the fan down depending on the size of the resitor. Just be sure that the resistor is not so large that the fan has any trouble kicking over.

When you get it quiet as possible tell us what you did and how quiet you got it.

[stidrvr]

FYI: The third wire, or the blue wire, is for a RPM sensor. Normally this is for used for computers. It also a signal to be sent through the motherboard and into the bios/software to know what the speed of a fan is running at, and also to trigger alarms when a certain fan has stopped spinning, or is running extremely slow.

[Wayne E]

Buy 2 low noise replacement fans. Cut the leads off the old fans and wire the new ones normally.

That's correct ... and exactly what I did. The fans I located were from my local Micro Center store. They were 26 dBA fans and ran $5.99 each. Made a tremendous difference in lowering the sound levels of the fans. Plus, the amp never ran any hotter after the modification.

[PoorboyMike]

I just did some measurements with the rat shack meter.

A weighting, slow, 1" away I get 65db.

C weighting, slow, 1" away I get 73db.


Now I want to try the free stuff 1st to see how it compares. The 1st thing I want to do is wire the 2 fans in series to drop them to 6v and do another measurement.

Before I do this though, is the way I described the wiring in my other post correct? In other words, wire them just like you would 2 speakers in series to one channel of an amp.

I'm also going to stop at the local computer store on the way to work and see what they have for quiet fans. If it's only going to cost me about $10, it could be helpfull to others to see if some free mods will work as good as forking out cold hard cash for quieter fans. I wont be able to post measurements until tomorrow though. Stupid job. :M

[Cowanrg]

look for panaflos. they are very quiet and reliable. they push a lot of air too. or you can get one with a thermistor control. it varies the voltage depending on the temperature of what the thermistor is attached to.

[Dennis H]

Before I do this though, is the way I described the wiring in my other post correct? In other words, wire them just like you would 2 speakers in series to one channel of an amp.

Yup that's how you do it. While you have it open, check the voltage. Some amps use 24V fans.

[PoorboyMike]

Yup that's how you do it. While you have it open, check the voltage. Some amps use 24V fans.

Cool, thanks Dennis. I'm at work now so I wont be able to try it out until tomorrow. I did check though and they are 12v fans.

[SteveCallas]

Holy crap 73db?!?! I thought the Nady came stock with variable speed fans?

[PoorboyMike]

Holy crap 73db?!?! I thought the Nady came stock with variable speed fans?

It says they are but there are only 2 wires going to each fan so I'm assuming it really isn't. If it somehow is, the 73db would have been the slow speed since I don't even have it hooked up to anything; just set it on a rug, turned it on, and took a reading.

[PoorboyMike]

OK, I wired the fans in series and it made a huge difference. I still get 60db on C weighting, 1" away, but it wont even register on A weighting. Airflow still seems adequate but I still don't have anything to power up to see how it does under a load. Hopefully soon.

[cjd]

Pick up some Nexus fans. Suuuper quiet while still moving air.

You'll know you have the right ones when you grimace at the color: orange. Though they have some new black frame white fan versions I think.

C

[Dennis H]

FWIW, the "quiet" fans do most of their noise reduction by turning slower and moving less air. It's true that they have more advanced blade/cowling designs but that's just icing on the cake. The main deal is they just move less air. Move less air and the blade/cowling design becomes less critical because they aren't operating on the performance edge between cooling and noise any more.

[PoorboyMike]

I already know that there are quieter fans available. My objective here was trying to find a cheap and easy solution. I still plan on ordering some quiet fans (so thanks for the tips everyone) but I want to wait and power this thing up and see how it cools as is. I'll start a new thread with all the details when I'm done.