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Post by Dan Laufman on Aug 10, 2010 0:07:55 GMT -5
I just finished reading most of this thread and am kind of surprised that this is an issue to some of you...
All of our amplifiers are rated very conservatively. One of our real strengths is that we are one of the companies out there who's gear actually makes it's rated power in an honest manner. We don't play games with the specs. This is why we show the AP results for all models.
Now, by it's nature, the AP test is not a long term test, but that does not mean the amplifier cannot make power for long durations. In development the amplifier are subject tor extreme stress conditions for long periods of time (heat soak testing is what we call it).
The amount of time the amplifier can remain under full load is a function of the number of channels driven, and at what power levels and impedances, etc. The test being proposed by one of the posters in not an accurate or accepted manner to test an amplifier, but if he wants to, have fun. He certainly won't kill the amp; possibly he'll reach a thermal trip point, but that's about it.
Those of you who have our amplifiers understand that they can be used in extremely "stressful" conditons and they do not break a sweat. They don't run hot and they have excellent design margin for their intended use.
Now, if you run a multi channel amplifier under test conditions with a resistive load bank with all channels driven to rated output, you will eventually cause the amplifier to thermally cycle. However, this takes place over a relatively long period of time. Say 30-45 minutes or more depending on the model and many other variables. If we reduce the number of channels being driven to full output on from five channels to three, it will probably never cycle.
We eventually come up on the thermal limits of the main power transformer, but this takes time. We use LARGE transformers on our units bur remember music is not continuous it's dymanic. The duty cycle on the amplifier in a real system when you are running the pants of of it is probably 10-20%. When you are loading it under test conditions at full output with ALL channels loaded it's 100% or more. This NEVER happens in the real world, so we do not design the main transformer to do this indefinitely, or it would have to be twice as big and the cost of the amp would go up tremendously for nothing.
We make VERY strong amps. They are honestly an conservatively rated and we invite comparison against any other product on the market. We're not hiding anything from anyone. Why do you think we show the inside of everything we make?
Of all of the things I'd imagine we'd ever have to defend... oh well.
Have fun. Big Dan
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Post by Mike Ronesia on Aug 10, 2010 1:16:22 GMT -5
LOL, all I know is my Denon clipped fairly easily and I've never had a problem with my XPA or UPA amps. I hope the test goes well and please use Lonnie's recommendations so we know it's controlled. Like he said, without testing other products for comparison the final results mean nothing.
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Post by brand450 on Aug 10, 2010 1:25:00 GMT -5
My procedure is simple. Will inject a input signal on the amp starting at a low output, say 1 watt and continue to progress up doubling the power every 10 minutes while monitoring the temperature of the heat sinks and transformer until the amp goes into clipping or becomes to hot to continue the test. All five channels will be driven. The total test will take 8 progression as I said starting at 1 watt and concluding at 125 watts if the amp makes it that far. Between the 64 watt and 125 watt progression I will allow the amp to cool for 10 minutes. The amp will be powered from a 15 amp circuit. Sounds simple to me and and an amp that is advertised to deliver 625 total watts continuously surely would have no problem with this. I will include pictures of the oscilloscope traces with the inputs referenced to the outputs at each progression as well as temperature of the sinks and transformer. Personallly I would prefer you useCE standardized test procedures. But if you are going to make up your own test then you should test multiple other amplifiers from other companies as a base line reference. Perferably something in the same power and cost factor. You will also need and this is very important, thermally stable non-inductive load banks rated for at least 250 watts or your test results will be whacked. A stable line source or the results will vary. You will also need a frequency compensated amp meter to assure your power measurements are correct. You should also note the ambiant temperature of the room to calculate the delta raise time. and for this kind of testing, some form of forced air induction will be needed. Good luck. One last thing. I woudl also recomend you do a real world test first. That is to say play a movie into the amp and note the steady state curent draw and power output as well as the dynamic charicteristics. What ths will prove is what the amp is designed to do rather than simulating a motor driver. I do enjoy reading Lonnie take this guy to school on this subject, it is surprisingly entertaining. I did enjoy the school comment and reading some of the more ridiculous comments made I have to think that when I go out with co-workers and *bleep* about customer A, B and C for being ignorant monkeys I cannot even imagine the conversations going on during happy hour with Lonnie and the gang. Come to think of it, I would like to get a couple drinks in Lonnie and see what he has to say about those who seem to enjoy rants on topics such as this.
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Post by rp on Aug 10, 2010 15:41:37 GMT -5
Lets take Bryston as example. They take each amp and put it in "burn-in table" stressing the amp during 100(!) hours of continuous testing. bryston.com/mission.htmlWould you give us a glimpse to the way Emotiva are doing the tests?
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Post by Lonnie on Aug 10, 2010 15:55:47 GMT -5
Lets take Bryston as example. They take each amp and put it in "burn-in table" stressing the amp during 100(!) hours of continuous testing. bryston.com/mission.htmlWould you give us a glimpse to the way Emotiva are doing the tests? Every amp gets 100% QA tested on the production line. Which includes power testing, power cycling, protection circuits cycled and heat soaked. Exactly how many hours I don't remember off the top of my head but I don't think it is 100. I think it is more like 12 hours which would represent roughly 6 months worth of real world use in a heat soak.
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Post by Dan Laufman on Aug 10, 2010 18:03:12 GMT -5
Lets take Bryston as example. They take each amp and put it in "burn-in table" stressing the amp during 100(!) hours of continuous testing. bryston.com/mission.htmlWould you give us a glimpse to the way Emotiva are doing the tests? We heat soak EVERY amp for 12 hours. Engineering development units undergo a much more rigorous accelerated life test. Emotiva UPA-7 - $699.00 Bryston 9B SST2 - $6,700.00 That's a a lot of dough. Six thousand bucks, to be exact. Tell you what, we'll give you a 20 year warranty and a 100 hour heat soak for another grand. Cash, check or charge? Operators are standing by! Apples to apples guys. Geez.
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Post by LCSeminole on Aug 10, 2010 18:07:36 GMT -5
Every amp gets 100% QA tested on the production line. Which includes power testing, power cycling, protection circuits cycled and heat soaked. Exactly how many hours I don't remember off the top of my head but I don't think it is 100. I think it is more like 12 hours which would represent roughly 6 months worth of real world use in a heat soak. Lonnie, Now I feel cheated out of 12 hours, when I thought my XPA-5 from the very first batch offered was brand new. That's roughly 6 movies, so if you'll just make sure I win one of those blu-ray give-away drawings at EmoFest all will be forgiven! ;D
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Post by johndavidson on Aug 10, 2010 18:10:43 GMT -5
Lets take Bryston as example. They take each amp and put it in "burn-in table" stressing the amp during 100(!) hours of continuous testing. bryston.com/mission.htmlWould you give us a glimpse to the way Emotiva are doing the tests? Every amp gets 100% QA tested on the production line. Which includes power testing, power cycling, protection circuits cycled and heat soaked. Exactly how many hours I don't remember off the top of my head but I don't think it is 100. I think it is more like 12 hours which would represent roughly 6 months worth of real world use in a heat soak. My experience with heat soak testing is the component is usually placed in a oven at a controlled temperature to simulate operational heat stress. These are not usually power on test. Is this correct?
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Post by Tyler wants bass! on Aug 10, 2010 18:27:44 GMT -5
Lets take Bryston as example. They take each amp and put it in "burn-in table" stressing the amp during 100(!) hours of continuous testing. bryston.com/mission.htmlWould you give us a glimpse to the way Emotiva are doing the tests? I think they need to get rid of the 90s pictures and update a little
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Post by Lonnie on Aug 10, 2010 19:41:16 GMT -5
Every amp gets 100% QA tested on the production line. Which includes power testing, power cycling, protection circuits cycled and heat soaked. Exactly how many hours I don't remember off the top of my head but I don't think it is 100. I think it is more like 12 hours which would represent roughly 6 months worth of real world use in a heat soak. My experience with heat soak testing is the component is usually placed in a oven at a controlled temperature to simulate operational heat stress. These are not usually power on test. Is this correct? Nope, a heat soak as it relates to audio amplifier testing is the amp is run on all channels at a specified level and driven to a point where the external chassis reaches 60c. Then it is run at that level for the specified time. If you read through CE stadardized test procedures it will explain the entire process.
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Post by Lonnie on Aug 10, 2010 19:46:25 GMT -5
Every amp gets 100% QA tested on the production line. Which includes power testing, power cycling, protection circuits cycled and heat soaked. Exactly how many hours I don't remember off the top of my head but I don't think it is 100. I think it is more like 12 hours which would represent roughly 6 months worth of real world use in a heat soak. Lonnie, Now I feel cheated out of 12 hours, when I thought my XPA-5 from the very first batch offered was brand new. That's roughly 6 movies, so if you'll just make sure I win one of those blu-ray give-away drawings at EmoFest all will be forgiven! ;D Keep it under your hat............its in the bag.
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Post by hemster on Aug 10, 2010 19:48:05 GMT -5
... Come to think of it, I would like to get a couple drinks in Lonnie and see what he has to say about those who seem to enjoy rants on topics such as this. Well buddy, make sure you get over to Emofest and I'm sure Lonnie wouldn't mind you buying him a drink! ;D
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Post by johndavidson on Aug 10, 2010 19:56:10 GMT -5
My experience with heat soak testing is the component is usually placed in a oven at a controlled temperature to simulate operational heat stress. These are not usually power on test. Is this correct? Nope, a heat soak as it relates to audio amplifier testing is the amp is run on all channels at a specified level and driven to a point where the external chassis reaches 60c. Then it is run at that level for the specified time. If you read through CE stadardized test procedures it will explain the entire process. So not full power, just until it reaches 60c or 140f. So, as i go forward with the full power test I should be safe up to 60c with out damaging the amp? I really do appreciate the opportunity to do this test and publish my results here.
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Post by johndavidson on Aug 10, 2010 21:56:30 GMT -5
I just finished reading most of this thread and am kind of surprised that this is an issue to some of you... All of our amplifiers are rated very conservatively. One of our real strengths is that we are one of the companies out there who's gear actually makes it's rated power in an honest manner. We don't play games with the specs. This is why we show the AP results for all models. Now, by it's nature, the AP test is not a long term test, but that does not mean the amplifier cannot make power for long durations. In development the amplifier are subject tor extreme stress conditions for long periods of time (heat soak testing is what we call it). The amount of time the amplifier can remain under full load is a function of the number of channels driven, and at what power levels and impedances, etc. The test being proposed by one of the posters in not an accurate or accepted manner to test an amplifier, but if he wants to, have fun. He certainly won't kill the amp; possibly he'll reach a thermal trip point, but that's about it. Those of you who have our amplifiers understand that they can be used in extremely "stressful" conditons and they do not break a sweat. They don't run hot and they have excellent design margin for their intended use. Now, if you run a multi channel amplifier under test conditions with a resistive load bank with all channels driven to rated output, you will eventually cause the amplifier to thermally cycle. However, this takes place over a relatively long period of time. Say 30-45 minutes or more depending on the model and many other variables. If we reduce the number of channels being driven to full output on from five channels to three, it will probably never cycle. We eventually come up on the thermal limits of the main power transformer, but this takes time. We use LARGE transformers on our units bur remember music is not continuous it's dymanic. The duty cycle on the amplifier in a real system when you are running the pants of of it is probably 10-20%. When you are loading it under test conditions at full output with ALL channels loaded it's 100% or more. This NEVER happens in the real world, so we do not design the main transformer to do this indefinitely, or it would have to be twice as big and the cost of the amp would go up tremendously for nothing. We make VERY strong amps. They are honestly an conservatively rated and we invite comparison against any other product on the market. We're not hiding anything from anyone. Why do you think we show the inside of everything we make? Of all of the things I'd imagine we'd ever have to defend... oh well. Have fun. Big Dan Well, I figured it would be just a matter of time before you chime in on this discussion. First let me say I have never said that the amps are of poor build quality or performance. In fact I am delighted with my UPA-5. It fully meets my power requirements and sounds every bit as good as the Carver it replaced. I do agree one hundred percent that music is dynamic and my UPA-5 will never be required to produce full power out of all five channels continuously. I doubt any of your amps will ever be required to produce their full rated power in the average home environment. But I am not the one making the claim in my marketing literature that it can, without ever breaking a sweat, in its comfort zone. You are! So let’s take a look at that. The UPA-5 is rated at 625 total watts continuous output with all channels driven. At the same time the documentation states the amp has a 600VA transformer. Since the term VA means apparent power. That means at a minimum the amp is already requiring 25 more VA than the transformer can deliver if pushed to 625 watts. Now let’s consider the overall efficiency of the amp modules. I will be very generous here and say they are 70% efficient which for the most part is the theoretical limit for an AB class amp (most likely they are more like 50 to 60%). That means that for the amp to truly deliver continuous 625 watts the transformer would now be required to deliver to the amp modules about 900VA or apparent power. This means that your transformer is now in a 50% overload condition. Short term I agree 100 % this is not an issue. Transformers are one of the most robust electrical components out there as long as they are not overloaded for more than short periods. How does that stack up against your claim of the amp being in its comfort zone not breaking a sweat delivering full power all channels driven continuously? Not well in my opinion! Overloading a transformer by 50% the voltage regulation on the power supply goes out the window and it will not be long before the transformer will be damaged unless thermal shutdown protection is provided. Any way I look at it that does not seem like without breaking a sweat. Since there are a lot of gear heads on the form, I really do say that respectfully, (I love cars) that would be like rating my max HP above the engine’s redline. Or maybe a better analogy would be a nitrous shot to get a peak burst of power but knowing anything long term or continuous will result in damage to the engine. I am not saying it has merit, it does, but then I am not the one making the claim of continuous full power output, you are! I know by now Lonnie is jumping up and down screaming that it is the secondary capacitance that supplies the amp modules not the transformer! However, unless Lonnie slept thru physics class he should be very familiar with the law concerning the conservation of energy: “We can neither create nor destroy energy but only change its form”. The amp is a closed electrical system. All the power that is required at the outputs plus efficiency loses must pass thru the transformer. Just because it does not pass thru in a linear manner does not mean that it still must not pass thru it. All the energy that is stored in the caps comes from the transformer during the rising portion of the ripple. So here is my position, yeah for a few hundred mili seconds the amp most likely can produce these power levels relying on the energy reserves in the caps, but not long term without putting the transformer into an overload condition. I don’t agree that overloading any component long term is a good sound engineering practice. Most people define continuous as well…..just that continuous, without interruption, without breaking a sweat. Does that mean it is not a great piece of equipment? Hell no! All I have been saying is these ACD continuous ratings are BS! They do not represent what most any lay person would consider being continuous and they can expect in their homes. There is no true standard and as an informed consumer everyone should know they are BS! As long as they meet the minimum FTC requirement manufacturers can claim about anything they want. I won’t post again. I fully expect this to be deleted. Have a nice day!
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Post by Wideawake on Aug 10, 2010 22:43:47 GMT -5
johndavidson, don't you know that all Emotiva amps are capable of over unity? It's a good thing that Lonnie slept through physics classes since otherwise he would have been bound by your silly "science" and we wouldn't have esoteric Emo equipment to confuse you so.
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Post by ÈlTwo on Aug 10, 2010 22:50:48 GMT -5
I'm guessing you expect this post to be deleted because you've already had this conversation, via email, with Lonnie. ;D
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Post by Deleted on Aug 10, 2010 23:43:30 GMT -5
"I won’t post again."
Thank you Jesus, thank you!
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Post by brand450 on Aug 10, 2010 23:55:47 GMT -5
"I won’t post again." Thank you Jesus, thank you! Amen!
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Post by Tyler wants bass! on Aug 11, 2010 0:12:19 GMT -5
As it's been said it does not need to put out full power constantly over a long period of time, the reserve banks are just for that, and once the tanks full you refill it. After a huge hit more power will be pulled from the wall for a short time for the capacitence to refill and then once they are topped it it would average out again. And like has been stated above, we are talking about audio amplifiers, not AC,DC motors or anything else like that with a duty cycle. Also, I'm going to go out on a limb and say you were on AVS before coming here with that last post
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NorthStar
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Post by NorthStar on Aug 11, 2010 0:20:05 GMT -5
I went to the best schools, I went to College, I went to University, and I was top of my class in Philosophy; was even offered to teach it! Now, one thing I truly know, is that people like John are very important people for forums like these where discussions are to take place between various schools of toughts. Without that, without people like John, there would be no discussions at all, period! ...And that's what makes us advancing in life. ...On all aspects.
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