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About 25 years ago at work we had a Lab/Test Berth which had a big old computer in it. The air conditioning was badly set up and when the lab was unoccupied overnight and weekends is got uncomfortably cold when the lab technician came to work in the morning. So he began to leave the computer turned on all the time functioning as a room heater, which was contrary to our operating procedures.
We soon discovered that this particular computer was far more reliable than similar ones used elsewhere. That's how we learned that continuous operation is more reliable than ON/OFF operation (at least for this type of computer).
Ah yes, heat. Class A operation is the reason for heat. Fact is, if you want it to sound right, it has to be class A.
I've never understood why a person would spend thousands or 10s of thousands on a stereo and then compromise the whole thing (and the investment) because they were worried about heat.
A customer of ours in Guatemala runs one of our big amps and has no air conditioning. Instead, he has ductwork positioned in the corners of the room where the amps are, and has a fan at the other end of the ductwork, drawing the air out of the house. His room stays comfortable year round even if the amps are on all day (I know I was there), yet the room is quiet. Elegant solution.
Well, there is more than just "HEAT" when there is heat, there are tradeoffs, for every degree something runs hot, there is a reduction in reliability, as well, the heat comes from somewhere, it's energy, wasted energy, you wouldn't run your car full throttle all the time an use the brake to go 30 miles an hour, there are intelligent ways to use energy
Joule Electra OTL tube-based amps. I have a pair of their 100 watt versions in my dedicated Canadian basement listening room. I close off the heating ducts to the room and turn on the amps an hour before I listen. Works great for me - I STILL have to have a blanket on when I listen to music in the winter.
Allanbhaganinfo, your analogy does not work. Class A amplifiers generate heat because they are on all the time. The engine in your car makes heat- all the time- because it is on all the time too. But it is not correct to compare the two!
Class A amplifiers get used not because they make heat but because they are the best sounding amplifiers made. IOW, any amp that is not class A won't sound as one that is (all other things being equal). Especially when one is investing thousands of dollars in an amplifier, one ought to be aware that the sound quality investment is better served by an amp that is class A (and runs hot).
It is assumed that the amplifier is also designed to handle the heat that it makes- we've been making class A amplifiers for the last 28 years and so far the heat of the tubes has not caused us any reliablity issues- and we get good tube life too. Its all in the how you handle Class A requirements.
I'd like to hear someone tell us how Atma Sphere amplifiers are anything BUT reliable. Personally, I haven't come across a more reliable amplifier, be it Class A, Class A+, Class A/B, Class B, Class D, or Class XYZ.
Yes, if you want heat, a Class A amplifier is your ticket. Nice in the winter. The power draw isn't a positive, but that's about it when it comes to drawbacks. I concur that Class A often goes hand in hand with great sound. The Atmas being as good a Class A amplifier as you'll ever come across, particularly if tubes are your cup of tea.
Never understood those who were running their Atmas in Class A/B mode. As I like to say, "In for a penny, in for a pound." In my opinion, you run your Atmas the way they are supposed to be run, with the kind of speaker they are supposed to be mated with, or you find some other amplifier.
Hi Ralph, yes, class A does have its sonic attributes, I never said it did not, but the heat is an issue, what you say go against studies done by the US military and us, showing that tube life is directly affected by heat, the higher the shorter the life, as well it goes against what has happen to so many Class A amp manufacturers in the past, going out of business due to reliability issues.
Class A tubes also deteriorate at a faster rate than ones in Class A/B amps, again due to the heat (or always being on).
A well designed Class A/B is harder to implement, "True" auto biasing and power supplies need much more attention , when this is achieved a Class A/B amp can be excellent but I agree, not too many get it right.
As for the analogy with the car, IMHO it's correct, Class A tube is on all the time, it requires the power, to be on all the time, from the supply, a well designed AB can be a factor of many times more efficient and many times cooler.
I'm not saying that Class A does not have it's place, but to say that Class A should be worth more than AB is wrong and misleading, AB can be more expensive and complicated to implement correctly and for people who don't want to risk their family and friend/Pets to burns or heat discomfort, as well for those with an eco conscience, Class AB can be as excellent if well designed.
Good tube life is relative, we have amps out there with the original tubes that are way over 20 years old.
I mean, don't take me wrong here, we will be making Class A amps again in the future, we just don't feel that it's worth more only because it's Class A.
Last of all, No one is saying that Atmaspheres are not reliable, my comment was general for Class A vs. Class AB and what heat does, and that is with us having 36 years of research in the matter.
Notwithstanding the perceived heat given off by the previously mentioned amps, no amp gives off more heat than its rating, which in the case of tube amps is about 300 watts, 500 watts tops. The smallest electrical space heater gives off more than that. It is silly to buy an amp for its "appartment heating" capacity.
We have a customer in Guatemala who has our biggest amps. He has no air conditioning, and does not need it (Minnesota is hotter in the summer than Guatemala...). This despite the amps often being on all day long; the room stays very comfortable. He does this by having vents in the ceiling above the amps. The hot air is then moved out of the house. It works very well indeed (I was there)!
Its probably not a good idea to choose an amp based on heat (or lack of heat) output. But it is a fact that if you choose an amp for its low heat output, it will represent a compromise in the sound of the system overall. So far no-one has been able to change the laws of physics...
Mark Levinson 33 run's really HOT.
A funny thing happened the other day. My amps were left on by my kids in my Music room with the door closed for 3 days. Did I freak........? The door is weather stripped and the room is relatively airtight.
The ambient room temp was 94 F . The room is set for 68 F. How is that for hot.
I am sure that my electrical meter was spinning out of control. Luckely our power is all hydro electric.
Hello Bryan, I've got a Rappaport Amp 1 in perfect working order. I rebuilt the outputs with hand-matched motorola OEM transistors and rebiased the unit about 5 years ago and it has about 30-40 hours on it. Just finding the proper output transistors was a complicated matter. Cosmetically it's in pretty good shape for its age and i would consider selling it for the right price considering its rarity.
O.k., this is an admittedly silly thread. That being said, it would seem as though getting hot running amps to also use as heat is serving two needs- audio and heat source.
Since we as adiophiles need both (if we're in cooler climates) it behooves us to use class-A amps. Better sound, throws off heat.
My listening room is in the lowest part of the house and is notably cooler than the rest of the house in both the summer and the winter. Hot amps work just fine for me!
Using a space heater would therefore be less efficient
because in addition to the heater, you need to run your amplifier(s)!
Any class-A OTL will heat just fine...
Pass Labs, Pah, runs a bit warm, but I could keep a hand on Aleph 3 for 10, 20 seconds. Now my Viva Solista 22watt SET is really warm. You can cook a meal and run the central heating with that, as well as being a great sounding amp. What I don't understand is that it is Italian, it is pretty hot there in the Summer, how can they stand it? I have to have a Karan K180 for use from may to September in the UK