How to keep my stack of Adcoms cool...


I have three older Adcom amps in my entertainment center (two GFA-555II's and a GFA-2535), and predictably, they generate a good bit of heat. I usually leave the door to the cabinet open, but I would like to be able to close it sometimes, as it gets in the way of my speakers, somewhat, when it is open. My thought was to install a couple of cooling fans (one sucking air in, and one blowing it out), but I am somewhat concerned about the noise. Does anyone know of any very quiet fans, or of any other tricks to keeping your amps cool?

Thanks, Tom.
tombowlus
An open rack is all I’ve ever used, and that obviates the open door issue. Raised a kid and neither her or her friends ever bothered my gear, and now with tube pre-amp and amp I give both a lot of space, and other than dusting things from time to time this seems to work swimmingly. I have seen an interesting thing called an Aircom S7 but you need someplace for that air to go...a back vent should do the job. The S7 claims to be quiet and self regulating and it's 49 bucks.
I run a Bryston 4BST in an open rack, but it still gets hotter than I'd prefer. Picked up a high quality 12vdc PC fan for about $15 on Amazon.....Noctua NF-S12A FLX........made in Austria.............very quiet, 18db, barely hear it with no music. Built a little cage for it, set it on top of the amp, problem solved, amp stays only slightly warm now even when pushed hard..............Agree on a closed cabinet being bad........45 years in high end electronics......nothing kills electronics faster than heat. My vote is for fans, probably two since you have 3 amps.........How you hook them up will depend on the details of your setup, but you HAVE to get the hot air out and cool air in.......or you'll be buying new gear pretty quick.
Slappy- it might be more of a concern in Car audio based on the "mobile environment", but I can see home audio geeks, er I mean cool guys like us, really getting into it.

Hell, you could have an amp that was warmed up to operating temp by warm water and end that annoying 20 or more minutes you have to endure of less than perfect highs or grainy vocals when you get home from work. You'd switch on your amp with it already at a perfect temperature for optimum listening...

As the evening progressed, the system would convert to cooling the water. A simple Peltier device could both heat and cool the water as needed, and as controlled by a simple thermistor. With the size of amps nowadays, and the ton of "aesthetically pleasing empty space" many contain, you could put the whole sealed pre-heating / cooling system inside the box. Carefully designed, the water could circulate via convection currents and wouldn't even need a pump. How cool (pun intended) would that be?

I think Eldartford's onto something, and the resident rocket scientist is probably in his laboratory as we speak converting an amp to liquid temperature control.
Pmkalby

Im not suprised that it was a car manufacturer that did that. Summer time the trunk of yer car is gonna get hotter than hell, add on 1000W mono amplifier driving a 4-2 ohm load, yer talking about brimstone fires of hell

Other than roasting a few dvd players, ive never really had heat problems in my home gear, my car gear on the other hand, now that has a tendancy to overheat pretty quick.
I definatly think it is a bigger concern in car audio.
Eldartford-- A high-end amplifier company has gone the liquid cooled route. Unfortunately, it's CAR audio high end-- Precision Power used to make amps designed to be liquid cooled if you wanted, or convection cooled if not. Many a show car of that era had clear coolant lines with brightly colored coolant water color-coordinating with the paintjob,etc. It worked quite well.
Wow, those are some quiet fans, Errivera! However, I had just ordered two Middle Atlantic QFans (50 CFM, 30db) and one of MA's Thermostatic Controls (turns fans on/off and varies fan speed based upon temp) before I read your post. We'll see how these work out.

Interestingly, I switched out my old "plain Jane" speaker cables for MIT AVt3 cables yesterday, and the amps seem to be running hotter at the same volume level. This could be due to the fact that the MIT's are brand new and haven't broken in yet.

Thanks for all the feedback, Tom.
If you need a really quiet fan check out the link below:

http://www.casecooler.com/casecooling.html

Notice at the bottom of the page is information regarding fans and fan noise. The Panaflow fans are probably one of the quietest fans you will come across. I have 4 of the 24 CFM fans in my computer and they are virtually silent.

Hope this helps.
You could probably use some PC fans, they are quiet enough that you wouldn't hear them when music/movies are playing.
Actually, I have always wondered why some high end outfit didn't come up with a water-cooled audio power amp. Advantages would include precise regulation of operating temperature (an advantage of water-cooled engines over liquid-cooled). However, the bigest motivation would be the braging rights in audiophile circles.
Throw water on them, that should do it...permanently. Just kidding, the set-up was too perfect and I could't resist.
If you are able to do things in the cellar, put the amps down there. This would be easier and better than ductwork. Run the speaker wires down there also.
Cytocycle:

I am not sure that the "extra power" deal would pan out if I switch to the Sunfire. My GFA-555II's are cranking out 850w (@ 4 ohms) into each of my CS3.6's, the bridged channel on my GFA-2535 is putting out 325w (@ 4 ohms) into my SCS3, and its two unbridged channels put out 60w (@ 8 ohms) into my AR TSW 110 surrounds. So, yes, the surrounds would benefit, but the rest would not. Those 3.6's really liked the extra juice, compared to running just one GFA-555II in stereo mode. That Sunfire is a great amp, to be sure, though.

Pmkalby:

That is an interesting suggestion. And quite doable, too. I have a full basement, and right below my entertainment center is drop ceiling with easy access. Plus, that would be cooler air moving through the cab... Nice!

Thanks, all.

Tom.
Sell your adcom amplifiers and replace them with a Sunfire multichannel.. It runs cool and can be closed up.. I had to do the same as I couldn't hide away a 125lb EAD Powermaster 2000 in a cabinet because of the heat generation, but my Sunfire Cinema Signature 225wattsx5 channels ran cool pushing 4 Magnepan 1.6's and an aerial center channel. Besides you will enjoy the extra power.
Locate a squirrel cage or better yet axial (like a jet engine) in the crawlspace or a nearby closet. Put a small furnace type fiberglass filter over its intake so you are blowing fresh, clean air (clean filter regularly). Run the fan's output to your cabinet via insulated flex duct or similar (a good S-bend will cut noise out of the fan to the cabinet). Dump the air supply into the bottom of the cabinet. Cut ventilation into the top rear, a bit smaller than the area of the hose's crossection.

You'll end up with a slightly pressurized cabinet, this will help keep dust out- fringe benefit. You'll also get good, quiet airflow through the cabinet. Pull the shelves the amps are on and take a hole saw to them (don't put holes where the amps' feet go...) If there's no flow around the back of the other shelves, give them the old swiss cheese treatment as well- the air will move up with the convection currents and out of the cabinet.

Any "muffin fan" type fan you cabinet mount WILL make a racket, if not from it's own rattling, then from vibrating the back of your cabinet.
if you DO decide to put a fan in to suck the air out, you might want to locate it in the middle of the back instead of the top. cause then it will pull all the heat to the top
You can't get around the fan in a closed rack. However, try putting the amps on the bottom of the rack near the floor. Don't play with the 555 when its gets hot it shuts down. Their are also passive chimney designs. The first guy responding was describing a type. Most are pretty unsightly.

I'm building a closed cabinet for my equipment but it has a fan that exhaust out the back.
Both good responses. However, the entertainment center option was a compromise solution, taking spousal approval factors into consideration. I am probably stuck with the unit (and it's fairly nice, for what it is). I am currently thinking about trying to re-engineer the door hinge so that it can be laid/slid flat with the side of the unit when open.

In the meantime, I plan on adding some ventilation holes at strategic locations. Hmmm, maybe just one fan, sucking air out near the top rear of the cabinet, with ventilation holes at the bottom near the front (underneath the amps, facing the floor, so you won't see it).

Still, I'd need to find a very quiet fan that still moved a good bit of air...

Thanks for the advice, Tom.
Ive seen alot of telecommunication racks use a passive ventilation system that works rather well, seeing as how delicate the electronics are.

Take some aluminum plates that will fit snug in the rack flush side to side. bolt the front of the plate about 2 inches above the the front of the adcom unit, and the rear of the plate about 4 inches above the unit. (doesent have to be exact, but you want it sloping backwards to pull the heat away.

when the heat rises it will be pushed out to the back of the cabinet and away from the gear.

Of course, you will need vents in the back of your cabinet for this heat to escape.

This method works better than people would expect.
Like i said, this technique is used in alot of communication racks with hundreds of thousands of very delicate electronic circuitry.

I think this passive method works better than the fans do, as the fans will either pull from above or from below, but either way whatever gear is at the end with the "Pulling" fan will get plenty of heat.

You could always couple this with a single fan placed at the bottom of the cabinet and have it blow up and slightly towards the door, providing cool air in the front that will help reduce the heat as well.

Careful with the heat dude.
I fried 2 dvd players because the reciever i was using was such a powerhouse it generated alot of heat.

personally i like open air racks the best. less to worry about. lot more dust though

Peace!
Yeah, don't put them inside cabinets. All right, you probably didn't want to hear that, but that's the answer. Fans might help somewhat, if they're positioned in a way that really circulates air over and past the amps. (But if both intake and outflow are in the back, they won't do that!) But fundamentally, heat-generating electronics do not belong inside wooden boxes. I'd consider getting a separate rack for them and tucking them in a corner somewhere.