Quieter fan mod for Behringer EP2500

**bob1029** · **03-06-07, 10:19 AM**

Interesting idea... Ill give it a try if my rti12s overwork the amp... (unlikely).

**brucek** · **03-07-07, 10:19 AM**

Quote:

Ok, i did the fan mod as well using the fan out of a computer psu. These fans are traditionally extremely quiet so i figured it would be a good place to start. The fan fit perfectly in place of the original fan, so no ninja rigging was required. I also used 2x 390 ohm resistors in parallel to make 195 ohms placed in-line with the (+) wire to the fan. The reason for running them in parallel is because they are smaller and i needed to get more to handle the heat dissipation.

But aren't computer fans 12 volts? The supply for the fan in your EP2500 is 24 volts? So, you would be at least dropping 12 volts across the 190 ohm resistors? That would dissipate about 3/4 watts steady state. So, two 1/2 watt resistors would be fine in a passive circuit, but a fan is a variable current device depending on its load.

Start up current requirements, or if the fan fails to start would place much more than 12 volts across your resistors. Start up or stall load of a DC fan is at least twice the steady state requirement. Hopefully you've spec'd the resistors wattage to accomodate this added dissipation requirement? Stop the fan with your hand and put your fingers on the resistors for a while and see if they are about to burn up......

brucek

**bigguy** · **04-10-07, 08:59 PM**

New information on Fan Acquisition...

Digikey.com had a wait time for ship till 10 May which eludes to "none in stock"...

After some research I found them at www.newark.com

under the part number

NMB FBA08A24L1A which is also the part number of the manufacturer.

Price was 8.71usd each and there are many in stock.

Hope this help anyone looking

Thanks
Dan

**bigguy** · **04-10-07, 09:01 PM**

Quote:

bigguy wrote:

Price was 8.71usd each and there are many in stock.

My bad... 7.75 each... what was I thinking

**bigguy** · **04-10-07, 09:04 PM**

Quote:

bigguy wrote:

My bad... 7.75 each... what was I thinking

Part Number 31K9990 at www.newark.com

There Sorry for the errors... I was looking at the wrong display when I grabbed the information... too many computers at one desk... 5 computers and 4 screens... bet you cant guess what I do for a living...?

**ccdoggy** · **04-15-07, 08:36 PM**

I just bought from Newark as per bigguy's suggestion (thanks!) and it came to like $14 after shipping (2 day ground). cant wait to get it installed.

**bigguy** · **04-22-07, 06:40 PM**

Howdy Folks,
I finally got the fan and did the mod... there was a pre/post test and I can say that the new fan was significantly quieter... (cant really hear it running) but you can feel it out of the front of the amp... Nice.

The mod was simple however, those of you buying a Behringer now a days will have some sort of tamper proof "hot glue" on the connector so you cannot do this mod without voiding the warranty. I just cut the wire at the old fan and soldered/heatshrinked it to the new fan. I dont really care about the warranty as I got mine at a good price and suspect it will last a while. (besides I do my own repair work

)

This was definitely something in the "win" category.

Thanks
Dan

**ccdoggy** · **04-22-07, 11:20 PM**

Thats exactly how i feel. i also just cut the wire and shrinked it to be safe.

It works great! however i did notice after along time of use, aka i was listening to rock for about an hour at pretty good volumes its does get pretty warm, almost on the verge of hot. however i am not worried as that temp should not actually happen in any reasonable volume level or movie use.

**buggers** · **05-01-07, 02:24 PM**

Hey Dan what's up?

Michael.

**Scott S** · **05-15-07, 05:51 PM**

MOD REQUEST: On/Off switch for Behringer EP2500 fan...

I just got a EP2500 a few weeks ago. The fan is audible but not to the extent that some people say. About as loud as a Xbox or something like it. Not bad, not good for movie viewing but not too bad.

I don't want to go and find a "quieter" fan for it. I'd rather have the option of having it on or off, instead. Especially when watching a dvd I'd like to just turn it off. Even the most ridiculous movies won't heat up a beast like this too much. (I am speaking from others experience's with the Europower amps.) Now for music or some seriously loud video gaming, I'd like to turn the fan on.

Is this an easy process? I don't want anything fancy. I wouldn't mind having a little wire or something out the back with a toggle for the fan. Dunno what would really work or if your need a special switch for it.

Any idea?

**ccdoggy** · **05-15-07, 09:49 PM**

I wouldent do it. it will heat up with just normal use, with no movement of air it will take allot longer to cool and will only heat up more and more.

Just replace the stock one with the one suggested and you will not have to worry about it at all. it is about the same difficulty to do a switch and with the replaced fan you would never need to even think about it.

**Danny** · **05-15-07, 10:00 PM**

And also with a switch you may forget to switch it on when working it hard. But I also agree with Steve in regards to it heating up too much even under low usage. With no air moving through you will likely damage the electronics.

**Chrisbee** · **05-18-07, 02:07 PM**

The power transistors are bonded to the tubular aluminium heatsink. Without a draught through the middle the heatsink will eventually get hot. There is nowhere for the heat to go. It can't conduct, can't radiate and it can't convect in a closed box. Even with a very quiet fan like mine the heat is safely removed to the outside of the box.

Try placing the external sensor of an ordinary (cheap) indoors/outdoors digital thermometer on your heat sink with the fan disconnected. Then play some heavy rock music like Metallica. I found the Black Album at a steady 100dB+ the most serious test of cooling so far.

**Scott S** · **05-18-07, 02:28 PM**

After reading all your comments I have decided to not to that. Heh. I figured it would be okay for to watch one movie with it off but I guess not.

Good thing I got paid today. I can purchase my materials for a dual RLp18 LLT I am building and I'll order a quiet fan.

Thanks!

**Chrisbee** · **05-18-07, 04:14 PM**

Quote:

Scott S wrote:

Good thing I got paid today. I can purchase my materials for a dual RLp18 LLT I am building and I'll order a quiet fan.

Don't forget you need a 24 Volt fan.

Twin 18s eh?

**Scott S** · **05-18-07, 06:27 PM**

Yep!

Here's the build thread: http://www.avsforum.com/avs-vb/showthread.php?t=845994

**Chrisbee** · **05-19-07, 02:20 AM**

Quote:

Scott S wrote:

Yep!

Here's the build thread: http://www.avsforum.com/avs-vb/showthread.php?t=845994

Some serious woofage! Should be fun.

I feel sorry for those who aren't even allowed a 1cuft box sub in their living room.

**BassMaster** · **05-19-07, 10:49 AM**

what about this crazy idea

Why not take take the top off the fanduct?
so the heat can go straight up
of course you have too cut some extra holes in the top cover
but at least its silent then

**Chrisbee** · **05-19-07, 11:05 AM**

Quote:

BassMaster wrote:

what about this crazy idea

Why not take take the top off the fanduct?
so the heat can go straight up
of course you have too cut some extra holes in the top cover
but at least its silent then

The top cover is already in close contact and screwed to the heatsink.
Limited conduction will take place but I can't recommend this as the only means of cooling.

A tall chimney would be a better idea than drilling holes in the top plate of your amp. Not only would this drilling invalidate the guarantee but will make the amp dangerous to children probing your new ventilation holes. Unless you were very careful it will probably be so ugly you could never sell the amp if you needed to.

**vitod** · **05-20-07, 05:59 PM**

This fan mod is very much worth it. Took 10 mins and reduced the fan noise dramatically!

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