The manual for the Aleph 30 indicates that it draws about 200 watts from the wall outlet, which as can be expected for a Class A amplifier remains essentially constant regardless of volume level.
Therefore it will put approximately the same amount of heat into the room as two 100 watt light bulbs. As a rough ballpark guess, I suspect that your Almarro draws in the vicinity of one-third of that amount, or perhaps a bit less.
Regards,
-- Al |
I'm running a 30 watt class A all tube integrated amp. It gets hot to the touch, but won't keep me warm in the winter. |
I just went from a 300b SET integrated amp to a SS Class A integrated and the heat is about the same.
Hope this helps. |
Thanks for the responses. Two 100W light bulbs: that puts it into perspective (although an idle Class A SS amp is not as efficient as a light bulb <- sad). Too hot to touch, but not putting out a significant amount of heat into a decent sized living room.
Almarro states power consumption of its 18 WPC A318B 300b SET at 260W, so assuming the same efficiency my A205A is drawing about 70W at the wall -- roughly 1/3 of 200W just like you said, Al.
Anyway, I guess the numbers from Pass and Almarro gives us an idea...
Pass: 30W/200W = 15%
Almarro: 18W/260W = 6.9%
Class A SS wins on efficiency in this case. |
My Almarro A318B draws 250w and it put out enough heat to warm a house:)
It seems a lot hotter than two 125w light bulbs. |
It looks like the A318B uses a pair of 6C33C's, which is an extremely hot-running tube. Its filaments alone consume in the rough vicinity of 40 watts per tube, assuming both filaments in each tube are used. So your EL84-based amp figures to be considerably more efficient.
Also, just to be sure the light bulb reference is clear, nothing on the Pass amp will come close to being as hot as the surface of the bulbs, since in the case of the amp the heat will be radiated from a much larger total surface area (the Aleph 30 manual indicates that the heat sink temperature will be between 120 and 130 degF). But the total amount of heat radiated into the room by the amp will be about the same as if two 100W incandescent bulbs were positioned at the same location (slightly more than that, actually, as my understanding is that an incandescent bulb will convert about 10% of the power going into it into light, the other 90% being converted into heat).
Best regards,
-- Al |
The First Law of Thermodynamics -- Conservation of Energy (as Al's practical example implies): All the energy you draw from the wall -- as consumption by anything in the chain, including the Romex inside your walls (see below)-- is going to end up as heat and radiation, save initially for the < 2 watts of acoustic power in the room on average, a fraction of which you will actually end up perceiving.
The Second Law of Thermodynamics -- All energy differences [gradients] tend to equilibriate over time in so-called "closed systems"; from that we deduce the concept of Entropy, and the gradual loss of the ability to do "work" in these isolated systems. A good deal of the acoustic energy that makes it into your ears ALSO ends up as entropy, heating up your skull just a bit: you are a space heater, too, and not just on account of your metabolism.
Here in my home town is a company that sells/sold seemingly magical money-saving space heaters nationally for around $435 -- nominally, anyway: Those Amish craftsmen are hard at work trying to keep up with the demand. My space heater is small and three-fingers-and-a-thumb light, and cost $15.97 from Wal-Mart. I love it!
You won't have to worry about the Third Law, or Nernst's Theorem, since neither you or nor your gear will be spending much time near absolute zero; unless the cable manufacturers come up with a new quantum effect that will, no doubt, unhinge your jaw.
So, unless you're worried about singed cats or blistered kiddie fingers, you can just figure it all pretty much ends up heating your immediate environs, regardless of classes, bias settings, or other such considerations. For a lot of electronic gear, I wouldn't want to believe the power consumption labels too religiously, unless the spec is backed up by real world certification. You can buy a gizmo to test your draw directly for pretty cheap these days, of course. BTW, that crummy corkscrew bulb in your reading lamp may not be saving you the big change this winter the manufacturers and hopeful magazine writers are suggesting. Consider the above... and think about it. We've mandated incandescents to a soon-to-be-upon-us abrupt oblivion anyway, even for central furnace weather. You'll enjoy the mercury residue and the optometrist's bills until decent LED options appear in abundance.
For more on Class A solid state and heat, take a look at a couple of the product manuals Nelson Pass has put up on his First Watt site -- they address heat sink temperatures explicitly.
One more BTW: Those conservation laws they talked about in school are intimately related to those abstract, mathematically esoteric "symmetries" theoretical physicists like to go on about, pretty much on a one-to-one basis. Interesting! Who'da thunk it? |
I run an X-250 into totem forests. according to the meter I never get out of class A, and they wail, I mean loud (Real loud) in a 14x20 room. I can stick my fingers right into the fins after an hour no problem. Warm, yes, very hot, no. Does taht help? That's 40 w class A.... |
In general, I would say a SET will be hotter. I could put my hand on my Aleph 3, comfortably for 20 seconds. The hottest amp I have had was a Viva Solista, you could coook breakfast on that. It is'nt only dependent on the tubes with a SET, the Solista was very hot with 2, 211 and 2, 845 valves. I use an Ayon Spark too, the same 623C tubes as the Almarro and it is'nt that hot.
So it must come down to circuit design too, as well as the tube.
The clear winner as a radiator, was the Viva Solista |
David12 makes a good point, tube type and overall design are factors to consider. My amplifier is 300b SET class A, 8 watts per channel. After being on all day(10-12 hours) the amp and transformers are only warm, never hot.I would think the 845 and 211 tubes as well as their respective power supplies will generate more heat. |
Al touches on it without being .....explicit.
Heat and temperature are 2 different things. A lit match has a far higher temp than even the most ambitious amp, while 100lb of class 'a' will heat a small house.
So, while the 100watt bulb will burn you try to unscrew it when on, the warm to the touch 'a' amp will actually put out more heat.
As kind of an aside, didn't I read somewhere that a person radiates about as much heat as a 100 watt incandescent?
Also, from the FWIW department, the very high efficiencies quoted for 'd' amps? In the case of the ICE modules 80%+, for the ASP modules at least, is for 'Plug-to-Speaker'. And than only at full power. Lower power is much less efficient, being close to traditional A/B at reasonable levels.
Other 'd' amps may NOT include the PS and quote in the 90s, again a full-tilt. |
Magfan, interesting (and good) comments. As kind of an aside, didn't I read somewhere that a person radiates about as much heat as a 100 watt incandescent? I hadn't ever read anything about that, but some quick calculations indicate it is correct. Obviously there will be very large differences among different individuals, but if we assume an average of 2250 calories burned per day (150 pounds x 15 calories per pound), and that as indicated here 1 food calorie corresponds to 4.2 kilojoules = 4.2 kilowatt-seconds, the corresponding power consumption calculates to 109 watts! Best regards, -- Al |
Sheesh!
When somebody says....'Do the math'! You take them seriously.
And yes, following all those conversions thru......spot on.
For the class 'a' folk, that's why a cabinet or other enclosure is generally a bad idea. Solutions? out there, and maybe one day I'll publish MY solution which not only cools the gear but keeps it clean and away from micro vibrations which some find......disturbing.
I'm sure I'm closer to 120 watts+, while my tiny neice probably barely breaks 75! |
In class "A", my Plinius SA 100 MKIII runs quite hot. The faceplate is hot to the touch, the heatsinks are hotter. My EL 34 VAC PA 35.35. doesnt't seem to put out near as much heat.
Dan |
I had a class A Musical Fidelity A100 and now have a 300b SET. No contest. The A100 ran much hotter. |
For Class A, the heat generated in inversely proportional to the Sensitivity of your speakers.
Since it is always going to draw 200W from the wall socket, the amount of energy "left" after driving the speakers will be spent as Heat...so a Totem may not cause the amp to generate too much heat but a Proac just might
in a Class AB, since the power input varies depending on the speaker load, this dissipation is tno too much of an issue (but since a percentage od the amp is biased into Full Class A, very sensitive speakers may still run with the amp on Class A mode)
I think in Tube amps, the Big Transformers usually use up a lot of power and hence on a apples to apples, for the same poser rating their heat generation could be much lower |
For Class A ... since it is always going to draw 200W from the wall socket, the amount of energy "left" after driving the speakers will be spent as Heat True, but it should be kept in mind that almost all of the power sent to the speakers will also be converted into heat, by the speakers, and will wind up contributing to the heat in the room anyway. Regards, -- Al |
My Aleph 2s run hot. During the summer months here in NYC, I have to turn the AC on to cool the listening room and then shut it off during listening. After about 3 hours of continuous playing through the Alephs, I can feel the room getting hot. Not unbearable until maybe 4 or 5 hours. But on really hot days, I switch amps. :) |
