• 01-08-2007, 09:02 PM
    aevans
    Class A - heat/power issues
    I've got 3 Kinergetics class A amps, they get about 150-200 degrees at idle/full load whatever.. they are always hot, hot enough to get the aluminum little soft. They also dim the lights/throw breakers when they are first powered up, each one has an external 10 amp fuse on the 110 side, and I have no doubt they are pulling 10 all the time.

    I've got them set up temporarily in a bedroom, the listening room is about to be constructed, I was wondering if anyone had recommendations/guidelines on how to keep the temperture of the room under 100 degrees and keep the house from burning down with the wireing.
  • 01-09-2007, 03:23 AM
    Dusty Chalk
    How to keep the room cool -- keep them in a separate room. Seriously, I have this one amp that generates a fraction of the heat, and I can't run it in the summer time, because I keep my door closed for the air filter.

    How to keep from overheating/melting/whatnot -- ventilation. Run a fan over them. Try putting some serious watercooling on them (like the kind they make for computers).
  • 01-09-2007, 05:24 AM
    kelsci
    Class A amps from what I have read usually operate wide open regardless of the audio power demand. Judging with my experience with hot amplifiers, I would only own something like this in a cool climate. I can assure you that you cannot use items like this in the S. Fla. climate, not even in the winter. I think that fans would only spread the hot air around the house or apt. I do not think that is the answer. I wish I could give you one.
  • 01-09-2007, 07:38 AM
    basite
    running a fan above them (preferably 2, one that sucks the air, and one that blows air onto them) and and constructing/placing them so the air sucked away by the fan goes to the outside, and the fan that blows the air over the amps, gets it's air from the outside,
    or just a cooling fan, which actually cools the air down before blowing it over the amps.


    Good luck,
    Bert.
  • 01-09-2007, 09:50 AM
    Rock789
    unless you design a system to transfer the heat outside the house... any type of fan or water cooling system will still heat your room...
    for the amp to get ~200 deg F, it must be highly inefficient, or it has a lot of current traveling thru it...
    200 deg F is very very warm! the hottest I have ever gotten a cpu while overclocking was ~60 deg C =140 deg F... (I have it set to shut down at 60 deg C)...
    and the reason it got this warm was due to a cooling fan failure...

    adding fans to your amp will probably take the surface temp down a little, but if it was not designed with fan's, I question it getting that hot... perhaps you should call the manufacture and see if this is normal...

    is there any type of protection to keep the hot surfaces from touching things (like curtains or your hand...)?

    later
    Mike
  • 01-09-2007, 12:57 PM
    SAEA501
    A true class A power amplifier runs full voltage at the collector of the output devices, which effectively runs the output stage wide open. The idea is to virtually eliminate device rise time and to reduce to near zero crossover notch ditortion. And, if properly designed, will come very close to this goal. Having the output stage running at maximum is the reason for the tremendous amount of heat this type of design generates. In theory, the amplifier has been designed with enough heat sink area to allow it to operate for extended periods without getting into thermal distress. But it has always bothered me to have any piece of equipment operating at these kind of extremes. I had a Bedini 25/25 years ago that was full class A and I used a fan on it, if for nothing else than some peace of mind.

    Put the amps where ever you want them and put a fan, or two, on them. Get some 4" square 12 volt models and wire them to a variable 12 volt DC power supply. This way you can adjust the air flow while reaching a happy medium with the fan noise level as well.

    If the power amps are taking out the breaker on turn on, I would run a separate circuit from your breaker box just for the power amps. That will take care of that problem as well.
  • 01-10-2007, 03:03 AM
    aevans
    The amps in question are one of the few class a amps to have a fan, so I'm not so much worried about the equipment getting overly hot as I am the room getting uncomfortable to be in. I'm thinking now that I will hang them from the ceiling, so that the hot air hopefully will just stay above me. if it's still too hot I can run a vent that will go through the attic to the laundry room and a box fan in between.

    As for the power, I think I'll put each amp on it's own 20 amp circuit, I have prenty of blank spots for breakers.

    it will look a little odd seeing 3 60 pound amps hanging from the ceiling, but I guess thats what it takes to get good sound.
  • 01-10-2007, 07:32 AM
    Rock789
    although you will be moving the heat source above you... if the amps are heating the entire room, their location will not change them heating the room...

    your fan idea to remove the heat from the room sounds good, but fyi, is there anyway you could perhaps keep the amps on the ground? perhaps put the vent fan's directly behind the amps on the wall? use the channel between wall supports as the duct to the attic?
    ... I have seen many restrooms with the vent fans behind the toilet, and they seem to keep the restroom smelling "not bad"... this would depend on the flow rate of the vent fans you use however...
    perhaps use a push/pull duct (a fan or two at each end of the duct...)

    imo, this would be easier than hanging the amps, but I don't know your house, so goodluck whatever you do ;o)
  • 01-11-2007, 01:33 AM
    Dusty Chalk
    Actually, that might work -- heat rises.
  • 01-11-2007, 09:06 AM
    aevans
    I'm thinking 2 feet of the 8.5 foot ceiling will be good and hot, I'll let you know how it turns out. I'm thinking of putting a/c return ducts high on the wall, so that it sucks the hot air back to the central air unit when it kicks on.
  • 01-11-2007, 12:58 PM
    SAEA501
    .....so then you'll be raising an already hot power amp into an area where the ambient temperature is warmer than where they are now. I'm not sure if that's such a good idea.
  • 01-11-2007, 01:26 PM
    Rock789
    what is the ambient temperature operating range of these amps?

    if you are going to be installing new ducts, just install the new ducts around your amps...
    no need to move the amps if they have the proper ventilation...
    like I said before, I don't know the layout, so if it is easier to install the ducts on the other side of the room and move the amps, then go for it...

    I never took thermodynamics, and yes heat rises... but... just placing the amps near the ceiling alone will not lower the average temp in the room... you will have x amount of heat energy from the amps, and the only way to cool the room is to remove the heat energy from the room...

    if the easiest way to remove the heat from the room is a ceiling exhaust fan or duct, then ignore my post and go with your plan ;o)

    just trying to save ya some work