Lonnie
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Post by Lonnie on Aug 8, 2010 20:44:49 GMT -5
Touche! ...About 3 to 10 RMS watts at most. Ya'll must be old if you listen with the volume turned down that low or married ;D Actually they are very close to being correct in a real world application. The dynamic characteristics are quite high, but the steady state draw is really very low. Which was the point I was trying to make all along.
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Post by johndavidson on Aug 8, 2010 21:29:29 GMT -5
Well you peaked my interest as well. This is copied out of the user manual for a 4B. Seeing that power consumption and heat dissipations are given I would think this amp was put under a long term continuous test. A/C power Before plugging in the power cord be sure your SST amplifier is specified for the correct a/c voltage for your locality. The voltage is listed on the label found at the upper right of the rear panel. The circuit feeding the 4B SST should be sufficient so as not to cause the circuit breaker to trip (15 amp min). Note: the 4B SST when operated with both channels delivering maximum power into 4 ohm loads, will consume all the available power in a normal household circuit, therefore a dedicated electrical circuit may be necessary with this situation. Never lift the safety ground to the amplifier nor remove the ground pin from the plug.Power Consumption & Heat Load At Idle - 170 Watts Max. Heat Dissipation - 580 Btu/Hr. 2 channels @ 300W @ 8 ohms - 1280 Watts Max. Heat Dissipation 8 ohms - 2320 Btu/Hr. 2 channels @ 500W @ 4 ohms - 2100 Watts Max. Heat Dissipation 4 ohms - 3750 Btu/Hr. Bridged @ 900W @ 8 ohms - 2040 Watts Max. Heat Dissipation 8 ohms - 3890 Btu/Hr.I don't see where anything is stated about how long the test was run or am I missing something? I would think the test would be long enough to have the amp reach a steady state temperature. Definitely this would be more than a few hundred mili seconds, more than a few minutes. Maybe that should be the time criteria! The amp should be able to maintain a given output at a steady state temperature that it could safely operate at and still stay with in the qualifying data such as THD. By George I think I got it!
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Post by johndavidson on Aug 8, 2010 21:48:27 GMT -5
Ya'll must be old if you listen with the volume turned down that low or married ;D Actually they are very close to being correct in a real world application. The dynamic characteristics are quite high, but the steady state draw is really very low. Which was the point I was trying to make all along. Can you truly say that if you don't know the speaker efficiency, the room volume, the program material, the SPL and the time?
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Lonnie
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Post by Lonnie on Aug 8, 2010 21:56:16 GMT -5
I don't see where anything is stated about how long the test was run or am I missing something? I would think the test would be long enough to have the amp reach a steady state temperature. Definitely this would be more than a few hundred mili seconds, more than a few minutes. Maybe that should be the time criteria! The amp should be able to maintain a given output at a steady state temperature that it could safely operate at and still stay with in the qualifying data such as THD. By George I think I got it! You could be right, or maybe they just calculated it based on the beta of the outputs, the current draw and the thermal mass of the heatsink and never actually tested it. Have you found any company that does long term measurements on this? just curious.
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Post by Mike Ronesia on Aug 8, 2010 22:43:39 GMT -5
I think the goal should be to have a standard so you can compare apples to apples. The actual numbers should become irrelevant for the most part, as all that's really important is knowing how units compare to each other to help with a buying decision and maybe, maybe how they match up to your speakers.
It seems a lot of company's give their gear generous ratings and some don't. I think Emotiva is in the later group.
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Post by roadrunner on Aug 8, 2010 23:23:08 GMT -5
Johndavidson
I am not quite sure I understand your fixation with the terminology of how "continuous" output is used or misused. The Audioholics.com article that you linked to and often quoted from concluded that ACD was a next to useless metric to use in evaluating amplifiers. Furthermore, the author listed a number of measurements he would like to see become standardized at the end of the article. It was interesting to see that many of those measurements are exactly what Emotiva provides in their PDF files of AP Tester Results.
The author, Gene DellaSala, went to great lengths to demonstrate the severe limitations of trying to use ACD to evaluate and compare competing amplifiers. As Lonnie pointed out in an early post, there is no real life use in gathering that information because it will tell you next to nothing about the quality of the amplifier. Gene has become a huge fan of the Emotiva amps over the past few years and has repeatedly given them rave reviews including awarding the "Product of the Year" accolades.
Below is the introductory statement Gene made when he reviewed the Emotiva XPA-2.
"Emotiva XPA-2 Two Channel Amplifier Review Gene DellaSala — last modified September 08, 2009 23:00
Not only does Emotiva have a winner on their hands with the XPA-2 two channel amplifier, but they’ve literally hit the ball out of the park with this creation rewriting the rule book on high performance amplifiers on the cheap. The XPA-2 is not only the most powerful amplifier that has come across my test bench, but it represents the best value in consumer two-channel amplification that I’ve ever seen. Quite frankly, when I think about it, the XPA-2 is a lone wolf in a pasture of sheepish amplifiers."
Reading his entire review will give you further insight into the build and sound quality of Emotiva's amplifiers. I highly recommend that you take the time to read all of the amp Reviews of Emotiva products on Audioholics.com and on HomeTheaterHiFi.com. You will find that Emotiva power amps can compete, toe-to-toe, with brands costing many times as much. You will also see that Emotiva tend to publish very conservative results on their web site.
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Post by Deleted on Aug 9, 2010 2:21:12 GMT -5
FYIwww.n4lcd.com/RMS.pdf".......... [Title 16, Volume 1, Parts 0 to 999] [Revised as of January 1, 2000] From the U.S. Government Printing Office via GPO Access [CITE: 16CFR432.1]
TITLE 16--COMMERCIAL PRACTICES CHAPTER I--FEDERAL TRADE COMMISSION PART 432--POWER OUTPUT CLAIMS FOR AMPLIFIERS UTILIZED IN HOME ENTERTAINMENT PRODUCTS.........."
"..........RMS Voltage is correct, but there's no such thing as RMS Power or RMS Watts..........."
"..........Flash: After 25 years, in 2000, the FTC finally got the RMS issue right, but added preconditioning which is simply cooking the power amp with a sine wave before testing its power (not too bright, and no relationship to music):.........."
"..........(a) The manufacturer's rated minimum sine wave continuous average power output, in watts, per channel (if the equipment is designed to amplify two or more channels simultaneously)--.........."
"............(c) The amplifier shall be preconditioned by simultaneously operating all channels at one-third of rated power output for one hour using a sinusoidal wave at a frequency of 1,000 Hz;.........."
"..........(e) Rated power shall be obtainable at all frequencies within the rated power band without exceeding the rated maximum percentage of total harmonic distortion after input signals at said frequencies have been continuously applied at full rated power for not less than five (5) minutes at the amplifier's auxiliary input, or if not provided, at the phono input..........."
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NorthStar
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Post by NorthStar on Aug 9, 2010 5:20:21 GMT -5
I think the goal should be to have a standard so you can compare apples to apples. The actual numbers should become irrelevant for the most part, as all that's really important is knowing how units compare to each other to help with a buying decision and maybe, maybe how they match up to your speakers. It seems a lot of company's give their gear generous ratings and some don't. I think Emotiva is in the later group. Hi Mark, Nice to see you popping up! I agree with you, and if you read reviews on power amps and receivers with lab tests on power performance into 8 and 4-Ohm loads with a 0.1% THD, and from 20 Hz to 20 Khz; and always from the same lab technician & from the same testing equipment, under constant measurements, you finally got your wish. And that you can get from several audio websites or audio mags. And that's what most people that are smart enough, like me, exactly do; read those lab tests with an open mind and a certain knowledge in real world application. * That's how I purchased most if not all my audio equipment (amps, receivers, etc.). - For speakers, you use those measurements with graphs as a guide, but the final decision is in the actual listening, of course; well I hope it is for most people as it is the most important part of the entire process and the Ultimate in decision making of our dedicated and passionated hobby. Wish you'd post more often Mark. Cheers and say Hello to the wife from me and Gab, Bob P.S. Chuckie, do you know what RMS stands for? Also, what is true Voltage? Where is that come from? What is exactly 1 Volt equals to? Who invented "Volts"? And what is Watts? What 1 watt really represents? How come we don't use "Horse Power" to rate our amplifiers?
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Post by wizardofoz on Aug 9, 2010 9:08:05 GMT -5
Watts on 2nd :-)
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Lonnie
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Post by Lonnie on Aug 9, 2010 10:02:30 GMT -5
Whos on first?
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Lonnie
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Post by Lonnie on Aug 9, 2010 10:31:30 GMT -5
I think I understand where the OP is coming from if he is used to building motor controllers. But what I think the OP is missing is that fact that the application and duty cycles of the products are completely different. If we were building motor controllers then yes, it would need to be tested for 24/7 use if that was the intended application. There is a big difference even in the motor control industry in regards to the controllers based on the duty cycle of the gear in relationship to the application. A motor controller for a conveyer system would probably need to be rated for 24/7 use where a motor controller for a hair dryer would not. In this application the duty cycle for peak power on all channels is extremely small given the dynamic nature of audio signals. In a real world use I can't think of one scenerio where full power would be required on all channels for more then a few hundred micro-seconds which is something I don't think the OP understands. In regards to the government stepping in and setting guide lines. This was proposed many years ago under the consumer protection act. What happened was the industry itself started to police its own actions and thus the government only set basic guide lines. As it is now, the AP is considered to be "Industry Standard" for all specifications and if every company was to use one for their specs, then everyone would be comparing Apples to Apples. Unfortunately not all companies use the AP, but that is changing as well and soon, everyone will. Just my .02
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Post by jackfish on Aug 9, 2010 16:02:52 GMT -5
The only standard I need are my ears. All the rest is wishful thinking hoping for something that is unlikely to occur.
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Post by johndavidson on Aug 9, 2010 16:36:22 GMT -5
I think I understand where the OP is coming from if he is used to building motor controllers. But what I think the OP is missing is that fact that the application and duty cycles of the products are completely different. If we were building motor controllers then yes, it would need to be tested for 24/7 use if that was the intended application. There is a big difference even in the motor control industry in regards to the controllers based on the duty cycle of the gear in relationship to the application. A motor controller for a conveyer system would probably need to be rated for 24/7 use where a motor controller for a hair dryer would not. In this application the duty cycle for peak power on all channels is extremely small given the dynamic nature of audio signals. In a real world use I can't think of one scenerio where full power would be required on all channels for more then a few hundred micro-seconds which is something I don't think the OP understands. In regards to the government stepping in and setting guide lines. This was proposed many years ago under the consumer protection act. What happened was the industry itself started to police its own actions and thus the government only set basic guide lines. As it is now, the AP is considered to be "Industry Standard" for all specifications and if every company was to use one for their specs, then everyone would be comparing Apples to Apples. Unfortunately not all companies use the AP, but that is changing as well and soon, everyone will. Just my .02 Been working and I haven't been able to keep up with the discussion I think everyone is looking at extremes. I am by no means suggesting that testing for days or even hours on end is justified. What I am suggesting is if you use the word continuous that it should represent something more than a few hundred mil seconds. A few hundred mil seconds is more like peak power. Just like the wall outlet in you home it has a "continuous power load rating" but it also is perfectly acceptable to draw higher power for a short time. If you are going to advertise that continuous means well.....just that continuous you should have some data that goes beyond a few hundred mil seconds to back it up. Of course Lonnie, you have already said that the amp does not have the thermal management needed to run a long term test at full power ACD and at the same time I am certain that a 600VA (watt) transformer can not convert the power needed for 625watts of output plus losses, so what is the point of carrying this discussion any farther? Is there any other place, hobby, discipline, science, etc.. that continuous has a different meaning other than the audio world? So I propose this as a solution. I get a 4 week break between the Fall and Spring semester and we have new test equipment on the way. I will, using old school procedures, scopes, function generator, meters, and IR temperature readers put the UPA-5 on the bench with 8 ohm dummy loads. I will happily report my results here!
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Lonnie
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Post by Lonnie on Aug 9, 2010 20:12:08 GMT -5
I think I understand where the OP is coming from if he is used to building motor controllers. But what I think the OP is missing is that fact that the application and duty cycles of the products are completely different. If we were building motor controllers then yes, it would need to be tested for 24/7 use if that was the intended application. There is a big difference even in the motor control industry in regards to the controllers based on the duty cycle of the gear in relationship to the application. A motor controller for a conveyer system would probably need to be rated for 24/7 use where a motor controller for a hair dryer would not. In this application the duty cycle for peak power on all channels is extremely small given the dynamic nature of audio signals. In a real world use I can't think of one scenerio where full power would be required on all channels for more then a few hundred micro-seconds which is something I don't think the OP understands. In regards to the government stepping in and setting guide lines. This was proposed many years ago under the consumer protection act. What happened was the industry itself started to police its own actions and thus the government only set basic guide lines. As it is now, the AP is considered to be "Industry Standard" for all specifications and if every company was to use one for their specs, then everyone would be comparing Apples to Apples. Unfortunately not all companies use the AP, but that is changing as well and soon, everyone will. Just my .02 Been working and I haven't been able to keep up with the discussion I think everyone is looking at extremes. I am by no means suggesting that testing for days or even hours on end is justified. What I am suggesting is if you use the word continuous that it should represent something more than a few hundred mil seconds. A few hundred mil seconds is more like peak power. Just like the wall outlet in you home it has a "continuous power load rating" but it also is perfectly acceptable to draw higher power for a short time. If you are going to advertise that continuous means well.....just that continuous you should have some data that goes beyond a few hundred mil seconds to back it up. Of course Lonnie, you have already said that the amp does not have the thermal management needed to run a long term test at full power ACD and at the same time I am certain that a 600VA (watt) transformer can not convert the power needed for 625watts of output plus losses, so what is the point of carrying this discussion any farther? Is there any other place, hobby, discipline, science, etc.. that continuous has a different meaning other than the audio world? So I propose this as a solution. I get a 4 week break between the Fall and Spring semester and we have new test equipment on the way. I will, using old school procedures, scopes, function generator, meters, and IR temperature readers put the UPA-5 on the bench with 8 ohm dummy loads. I will happily report my results here! Since your still in school be sure to talk with your professor about power supply design as it relates to audio amplifiers and you will see that the amps do not run off of the transformer. Instead they run off of the secondary supply which is why the amp can produce its rated power. I would also suggest doing a little research into CE certification testing. It will give you a lot of insight.
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Post by johndavidson on Aug 9, 2010 21:12:51 GMT -5
Been working and I haven't been able to keep up with the discussion I think everyone is looking at extremes. I am by no means suggesting that testing for days or even hours on end is justified. What I am suggesting is if you use the word continuous that it should represent something more than a few hundred mil seconds. A few hundred mil seconds is more like peak power. Just like the wall outlet in you home it has a "continuous power load rating" but it also is perfectly acceptable to draw higher power for a short time. If you are going to advertise that continuous means well.....just that continuous you should have some data that goes beyond a few hundred mil seconds to back it up. Of course Lonnie, you have already said that the amp does not have the thermal management needed to run a long term test at full power ACD and at the same time I am certain that a 600VA (watt) transformer can not convert the power needed for 625watts of output plus losses, so what is the point of carrying this discussion any farther? Is there any other place, hobby, discipline, science, etc.. that continuous has a different meaning other than the audio world? So I propose this as a solution. I get a 4 week break between the Fall and Spring semester and we have new test equipment on the way. I will, using old school procedures, scopes, function generator, meters, and IR temperature readers put the UPA-5 on the bench with 8 ohm dummy loads. I will happily report my results here! Since your still in school be sure to talk with your professor about power supply design as it relates to audio amplifiers and you will see that the amps do not run off of the transformer. Instead they run off of the secondary supply which is why the amp can produce its rated power. I would also suggest doing a little research into CE certification testing. It will give you a lot of insight. I will do that Lonnie . Until then I will stay quiet on the subject as I think I have made my point clear. However I was hoping that you would invite me to present my results here.
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NorthStar
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Post by NorthStar on Aug 9, 2010 22:17:02 GMT -5
I will do that Lonnie . Until then I will stay quiet on the subject as I think I have made my point clear. However I was hoping that you would invite me to present my results here. But I do John! ...And I'm sure Lonnie doesn't mind at all.
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Lonnie
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Post by Lonnie on Aug 9, 2010 22:20:30 GMT -5
I will do that Lonnie . Until then I will stay quiet on the subject as I think I have made my point clear. However I was hoping that you would invite me to present my results here. But I do John! ...And I'm sure Lonnie doesn't mind at all. Not at all, I already know what he will find if he follows CE testing. ;D
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NorthStar
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Post by NorthStar on Aug 9, 2010 22:25:43 GMT -5
But I do John! ...And I'm sure Lonnie doesn't mind at all. Not at all, I already know what he will find if he follows CE testing. ;D I bet you do! ;D
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Post by johndavidson on Aug 9, 2010 22:41:29 GMT -5
But I do John! ...And I'm sure Lonnie doesn't mind at all. Not at all, I already know what he will find if he follows CE testing. ;D 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.
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Lonnie
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Post by Lonnie on Aug 9, 2010 23:30:54 GMT -5
Not at all, I already know what he will find if he follows CE testing. ;D 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.
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