I am not a troll. 🤥 Millercarbon is a Master Debater.
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I have central A/C, but you deal with what you have. I keep my class A biased amps off, then then turn them on about 30 minutes to an hour, before I listen. I mean totally off with the power switch on the back. I have an upstairs dedicated sound room, therefore I turn both the heat or the A/C on hours before a listening session. |
I’ll have to say I enjoy reading almost everyone’s point of view. There are some that insist on creating a war of words. This is aggravating. I too have posted too many crazy contributions, after having adult beverages. At times I will ask questions, that I know the answers to, just to get opinions. I always like to learn. No one knows it all, although some will have you believe they do. I always like to read what Raul has to say, although I don’t always agree. I have several favorites, but they will go unmentioned. |
I have always preferred Class A amps with properly designed heat sinks that cool sufficiently without and added fans (which might fail, possibly cooking your amp). I have one system that runs two mono Class A amp, each of which puts out around 400 watts in heat just sitting idling (they actually put out less heat when working hard as some of the current is used in outputting sound). They run hot as Hell but were intended to run that way, and have been for more than 30 years The problem with this sort of heat sinking is that it tends to be pretty large physically. The ones I use are 16.5" high and weight more than 100 lbs. each. I would get nervous with any amp that would turn to trash if a fan motor failed and you didn't notice immediately. |
At full Blast, my amps run slightly warm. I attribute it to the huge power supplies that allow the outputs to coast as they alow the electricity through, rather than working hard to extract it from a small power supply. The amps use very little bias, because it is not necessary, and causes heat to be produced. Since the amps a in the next room, I did use a small fan on a Bryston for a while. One interesting design for an amp is the Audire Monarch. It is a tower lined with many output transistors, and has an open bottom to let air rise for cooling out the highly vented top. The design reminds me of the old GE tube amp my family's movie theater used in the 1950's, but could have been even older.. It was 100 watts, about 5 inches thick, at least a foot and a half wide, and about two feet tall. All visible surfaces were totally perforated. Some audiophiles like to open the tops of their amps. This did help my Bryston run cooler. |
@tomavodka: It’s very normal for Krell amps and most class A biased amps to become very warm-some even hot to the touch. Be sure not to impede the air flow around them, thus no stacking other components on top, or placing them inside cabinets etc. Common sense stuff. Remember-a class A biased amp is always “wide open” when turned on. I have stated this comparison many times. They’re like a hot fuel dragster sitting at the line waiting for the the green light. Steve |
"Did I mention it was the old Phase Linear with the huge heat sink fins?...........Bob thought it was pretty clever."Bob cut his first grade elementary school classes and did not read the warning on page 3 of Phase Linear amplifier instruction manual. https://bradshirakawa2.files.wordpress.com/2013/06/phase-linear-400-ii-instruction-manual.pdf NOTE: page 3 is the page between page 2 and page 4 (it is not numbered like 2 and 4) |
"Well this was winter so we put some snow in a plastic bag in between the heat sinks."Many, if not most, of instruction manuals start with "do not expose to moisture/water" or some variation of thereof. Not that it should be mentioned, but apparently.......well, apparently not everyone reads instructions most have learned early in life. First grade of elementary school early. While at that, do not use hair dryer in the bathtub. |
I have to house my amp in a cabinet. There is significant upper air space but limited on the sides. The back is fully open. I use a temp controlled Middle Atlantic Cab-Cool that is installed at the top of the enclosure extracting air from front to back. It is rarely on. Works great. It is nearly dead silent. Even looking at it it is difficult to tell if it on or not. |
I'm now in Austin, which gets very hot in the summer. My listening room upstairs is cooled by a separate HVAC system from the rest of the house, but it was still a tad warm in the summer when temps easily exceed 105F during the day and don't drop much at night. The upstairs HVAC system was checked "OK" by a tech as recently as a month ago and was fine. Then, a week or so ago, the compressor died. I replaced the entire outside unit with the more current model that uses a variable speed compressor- what a difference! Even though the old unit had checked "OK" it wasn't nearly as effective as a fresh unit. Dead quiet too. I do use some of those AC Infinity units to cool a silencer box for the air compressor that is part of my tone arm set up. It has a temp probe and the fans kick on (intake and exhaust) at a chosen set point. Fairly inexpensive and seem to work fine after 3 years. I have the fans set to full speed and you can hear them in the room where the silencer box is located, but I suppose if they are set to a lower speed, they'd be quieter. I'm running all tube gear in the main system, from phono stage through amps. |
I do not use any kind of cooler on my two-channel analog system, even with its 100wpc tube amp. It's just not needed. However, I found that modern multi-channel AV processor/receivers certainly are in need of additional cooling (mostly due to the A/V boards, I think) so I utilize a Cooler Guys twin fan cooler on top of my Integra receiver that draws the hot air up and out of the unit and allows it to run much cooler after a double feature movie night in my HT room. |
Which Krell do you have. I have the KSA-80B and while it runs warm, it does not get hot. Perhaps refer to the owners manual and see what they reccomend for a temp. Does it trip the fail safe? I drive my one Ohm Apogee Scintillas and I have never tripped the saftey. It might be that your amplifier needs to have its bias adjusted, or perhaps its time for a tune up. I had mine rebuilt at the Factory about a year ago. You might also call Customer Service at Krell and ask them. Mr.bailyhill, It's a pandemic project and my first experience with class A amps. I aquired the Krell FBP 400cx stereo amplifier. I'm in the process of preparing my electrical requirements for proper placement and operation. All this before I enjoy blowing my walls out. I like to take informed steps from everyday users. Thank You for your input! Be well.. |
amg56, Thank you - that is exactly what I was looking for and the price is low, for nicely finished product like that: https://www.acinfinity.com/receiver-amp-cooling-fans/ |
Definitely the acinfinity component fan systems. These are sized to match the size of a typical component and have various models that blow the hot air to the front or back, top or bottom of the amp and are temp activated or remotely triggered by the temp of an adjacent component. Really good equipment. 🇦🇺 |
Which Krell do you have. I have the KSA-80B and while it runs warm, it does not get hot. Perhaps refer to the owners manual and see what they reccomend for a temp. Does it trip the fail safe? I drive my one Ohm Apogee Scintillas and I have never tripped the saftey. It might be that your amplifier needs to have its bias adjusted, or perhaps its time for a tune up. I had mine rebuilt at the Factory about a year ago. You might also call Customer Service at Krell and ask them. |
DK....easy 'nuff with dc....;) "Sous, sous, sushi...." Sorry, old Tubes number....couldn't resist. Spouse is hooked on 'food porn'....'Chopped', Beat the Flay, Wurst Kooks....all that.... "OK, 'chefs'....for our 'alien entre'....Open that basket....if you dare...." *horrible screams and sound of crunching bones...* "Well, I guess the chefs are on the menu tonight..." |
Running 3 4"dia. ’puter fans atop my SS amp, ’blowing in’ the grate. Have only triggered the ’fail safe’ once.....and I was being pretty enthusiastic. 12vdc with a wall wart, leave it on 24/7/365.25. Keeps the dust away as well...cheap insurance. If it has a grate, it gets ’fanned’. I don’t understand why tube amps don’t come with them. If those heat sinks get hot, they’d benifit as well. 'Ell, my 'puter has 4. Power supply, CPU, and case (of course), but also one on the graphics card that cools the audio card as well. And I'm considering adding an exterior pair as well. Gotta stay 'chill'... "I love the smell of hot electronics....NOT." ;) |
I have a Parasound 5 channel amp in my home theater system. There are only a few inches between the amp and the shelf above. I use one of these with front exhaust. It works great and is very quiet. They also have models with top and rear exhaust. https://www.acinfinity.com/component-cooling/component-fan-systems/aircom-s10-receiver-and-av-component-cooling-blower-system-front-exhaust-17/ |
Ideal would be the fan that forces air from bottom to the top of the heatsinks. Any air speed would be much better than cooling by convection only. There are very quiet slow fans available, but positioning them might be difficult. My amplifier runs only warm, but lowering temperature always extends life of electrolytic capacitors. Some of the laptop coolers are advertised as quiet, but it might be still audible while fans are likely positioned in wrong places. I'm thinking about building 1-2" tall base with quiet fans in the proper location and side air intakes. Good, easy home project. |
One time at a party the heat sink fins were getting hot to the touch. Like you did not want to leave your hand on there hot. Well this was winter so we put some snow in a plastic bag in between the heat sinks. Another time at a party suddenly no music. When I go to investigate there's a bunch of guys scratching their heads, trying to reassure the poor owner, nobody really knowing what to do. I said it got hot, protective relay, put it out on the deck and in ten minutes the winter air will have cooled it down and we can party on, Garth. Which we did. So scientifically speaking its best to do your hard rocking amplifier over-heating in the winter time. |
Ebm, I understand.... I just aquired a class A, Krell Amp. The previous owner had it a ac cooled ventilation set up. I'm aware these types of amps create substantial amount of heat. My room is temperature controlled but with the summer months I wanted to properly assistance ventilation.. I'm aware that high heat and poor ventilation shortens the life of stero amplifications. Thank You for your thoughts! And stay safe! |
