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Post by ocezam on Mar 15, 2013 7:30:55 GMT -5
Do you think that switch should after come 4 to 6 minutes of idling? There has been a lot of Emotiva involvement in this thread. I'm interested to hear a reply on this issue. Not unless they've incorporated some kind of power save feature. 34 pages with lots of Emotiva involvement, no mention of that feature. I'm also a little put off that you can actually hear the switch. And it seems to be happening WAY TOO EARLY. This situation is concerning. My amps will be here today. Hope I don't have the same issue.
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Deleted
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Post by Deleted on Mar 15, 2013 7:40:45 GMT -5
I hope this is an anomaly. The amp should stay in class A mode indefinitely when in said mode and the temp does not exceed its limits, unless the temp switch is faulty.
I don't like the sound of audible clicking in an amp when in normal operation.
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Post by ocezam on Mar 15, 2013 7:47:03 GMT -5
Darkranger,
How warm is the amp when it is doing this clicking? Don't need a actual number, just how warm is it "to the touch"?
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Post by willcycle on Mar 15, 2013 8:05:48 GMT -5
Dark Ranger, I am not surprised the amp is switching to class A/B operation after a few minuets use presumably due to high temperature. I have a Krell KSA-250 power amp that is supposedly class A but is in fact a high bias class AB amp with the first 30 watts or so of 250/ch into 8 ohms in class A. This amp gets very warm (almost too hot to touch after an hour) and the heat sinking is massive on it - I would estimate approximately 25 lbs. of aluminum. I do not see how the relatively limited heat sinking in the XPA-1L could keep the power transistors cool enough over time without some kind of forced air cooling.
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Post by audiophill on Mar 15, 2013 8:41:22 GMT -5
Received my pair of xpa1'ls at 8:30 this morning! I have numbers 46 and 69. I will give my opinions probably on Monday so i have enough time to compare them against my xpr-5! My first impressions are very good, packaged just like my oppo was, including the nice black cloth bag!
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Post by garbulky on Mar 15, 2013 8:44:10 GMT -5
I'm confused about the click he heard. Because if the click is the class A to AB transition why dont we hear it in any of the other AB amps that we have when beginning to play music? I have a question to DR. Remember how your xpa 200 when you turn it on it makes two clicks - one when you power it on and one a few seconds later when the channel leds light up. Are any of those clicks missing on the xpa-1 L?
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Post by Jim on Mar 15, 2013 8:44:14 GMT -5
I wouldn't think there would be a click when switching into A/B mode, since Keith mentioned previously that it can switch into A/B on the fly -- just for peaks.
If it employed a relay for A/B behavior, it wouldn't be able to change quickly - and it would be audible. I doubt this is the case, since lots of amps transition to A to A/B without anything mechanical.
I bet there is more to the story.
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Deleted
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Post by Deleted on Mar 15, 2013 8:58:10 GMT -5
My Xpa-1's click all the time ;D
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Post by Jim on Mar 15, 2013 9:11:24 GMT -5
My Xpa-1's click all the time ;D Heat sink clicking doesn't count! ;D
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Post by monkumonku on Mar 15, 2013 9:14:05 GMT -5
You know what would have been nice to have, although it is too late now, is an indicator on the amp that shows which mode it is in. It would be interesting to know when it switches over from A to A/B. Sounds like Dark Ranger's method of measuring the current works fine but something easier would have been interesting to have.
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Post by Jim on Mar 15, 2013 9:17:15 GMT -5
You know what would have been nice to have, although it is too late now, is an indicator on the amp that shows which mode it is in. It would be interesting to know when it switches over from A to A/B. Sounds like Dark Ranger's method of measuring the current works fine but something easier would have been interesting to have. You mean like this? Just kidding. Yeah, I think an indicator would be cool too.
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Post by monkumonku on Mar 15, 2013 9:23:03 GMT -5
You know what would have been nice to have, although it is too late now, is an indicator on the amp that shows which mode it is in. It would be interesting to know when it switches over from A to A/B. Sounds like Dark Ranger's method of measuring the current works fine but something easier would have been interesting to have. You mean like this? Just kidding. Yeah, I think an indicator would be cool too. ;D That was great. ;D
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Post by Dark Ranger on Mar 15, 2013 13:54:51 GMT -5
Hi guys, I'll do my best to answer the questions posed. I want to be clear that I'm only reporting my experience with the 1L so far. This isn't my first amplifier from Emotiva, but it is my first "Class A" amp. Maybe I just got (un)lucky if this is not how the 1L is designed to work. Maybe I'm misunderstanding how Emotiva designed the amplifier to work. I don't want to accuse anyone before I have all the facts...thus my extensive time spent on testing. This is why I'm asking for help to confirm my findings. For those who have received or will be receiving their 1L amps, let me know if this happens to you. OK, in order of posted response: Dark Ranger it sounds like you are only getting 5 minutes of Class A operation. Can you try putting a fan blowing on the amp (heatsinks through vents) and see if you get longer in ClassA before the click over to AB. Then you could see if this may be a temperture thing. Wether it is idling or running at 35 watts (classA), would it not use the same power and cause the same heat. I do have a fan just outside of the room blowing cooler air into the room. The ambient temperature is between 73 and 75 F. I will try adding another fan blowing directly on the amp. I want to try removing the top cover and see if I can get additional run time before the click occurs. Otherwise, I agree with you (based on my understanding of Class A) that is should consume the same amount of power and release the same amount of heat whether idling or playing content within the 35 watt range. Per a previous comment from Lonnie, the amp will switch from Class A to Class A/B when it reaches a certain temperature to protect the Amp. That's what I'm wondering about, if this is indeed what is happening. DR...do you have one of those non contact meat thermometers? It would be interestesting to track temp along with time to see if that relates. I bet it does. If so, the idea of a fan makes sense. But it would seem odd that it would only run 5 minutes in class A at low volumes before it switches. I have a non-contact infrared thermometer that I've used to measure temp. I've been able to record temperatures at certain locations when the click occurs. So far, these temps are fairly consistent each time the click occurs. The measurements were taken with the top cover on. Temps will be posted soon. I want to run a "cold" test in Class A mode. Well I hope it's not cutting in so soon for temperature. Where is the xpa-1 L being stored? Is it on another amp? It's also possible that your current influx measurements you got was simply due to something that needed slow charging and then dropped off after it was done maybe? Right now, the amp not installed in the rack. It's pretty much in the middle of the room. Here is a pic I just took. So as you can see, the amp is getting plenty of room to breathe. I also have a fan outside of the room blowing air into the room. I will try a second fan on the amp itself to see if it makes a difference. Do you think that switch should after come 4 to 6 minutes of idling? There has been a lot of Emotiva involvement in this thread. I'm interested to hear a reply on this issue. Not unless they've incorporated some kind of power save feature. I considered that, too. Perhaps it was a clever power save feature. To test my theory, I ran a test by playing content. The amp was turned on in Class A mode and it was running full bore according to the amperage draw stats. I then immediately started playing music at reasonable levels. No difference, the amp clicked about 5 minutes in, the amperage draw decreased significantly, and it stayed like that until I turned off the amp. I'm also a little put off that you can actually hear the switch. And it seems to be happening WAY TOO EARLY. This situation is concerning. My amps will be here today. Hope I don't have the same issue. Hopefully you don't have this issue. I would be interested in your thoughts if you can find a bit of time to test. I hope this is an anomaly. The amp should stay in class A mode indefinitely when in said mode and the temp does not exceed its limits, unless the temp switch is faulty. Yes, I hope this is an anomaly. Based on my understanding of Class A, what you said should occur. How warm is the amp when it is doing this clicking? Don't need a actual number, just how warm is it "to the touch"?... Yes, the amp is definitely quite warm, but not hot. I can easily keep my hand over the hottest parts without burning. In Class A mode, the amp definitely runs warmer than any of my other gear, including the UMC-1. I will have some official temps shortly. I'm confused about the click he heard. Because if the click is the class A to AB transition why dont we hear it in any of the other AB amps that we have when beginning to play music? I have a question to DR. Remember how your xpa 200 when you turn it on it makes two clicks - one when you power it on and one a few seconds later when the channel leds light up. Are any of those clicks missing on the xpa-1 L? The 1L clicks twice just like my XPA-200. After the initial push-button click (not counting that one), there is Click #1 while the indicator LED is red, then Click #2 when the LED switches to blue. No missing clicks at any time. The procedure is identical to my XPA-200. The click I heard in Class A mode is much quieter than the first two clicks. It is also in a different location than the two power-on clicks. I wouldn't think there would be a click when switching into A/B mode, since Keith mentioned previously that it can switch into A/B on the fly -- just for peaks. If it employed a relay for A/B behavior, it wouldn't be able to change quickly - and it would be audible. I doubt this is the case, since lots of amps transition to A to A/B without anything mechanical. I bet there is more to the story. I hope you're right. Phew, long post.
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Post by Dark Ranger on Mar 15, 2013 14:48:53 GMT -5
Here are two temperature/time tests I just performed.
------------------------------------------- Cold amp test (heard click 13m 52s into test)
Kill-A-Watt (pre-click): 2.5 amp draw from 1L during idle
Temperatures recorded at click:
right rear chassis: 97.1 F right center chassis: 107.6 F right front chassis: 95 F right side chassis: 93.5 F
heatsink left: 103 - 119.5 F heatsink right: 102 - 114 F
left rear chassis: 88 F left center chassis: 91.3 F left front chassis: 87.6 F
Kill-A-Watt (post click) - 1L current draw decreases to 1 amp and remains steady
-------------------------------------------
- 5 minute cool down -
-------------------------------------------
Warm amp test (heard click 4m 16s into test)
Kill-A-Watt (pre-click): 2.5 amp draw from 1L during idle
Temperatures recorded at click:
right rear chassis: 98 F right center chassis: 107.6 F right front chassis: 95.8 F right side chassis: 95 F
heatsink left: 108-119 F heatsink right: 104 - 118 F
left rear chassis: 87.6 F left center chassis: 92.5 F left front chassis: 88.7 F
Kill-A-Watt (post click) - 1L current draw decreases to 1 amp and remains steady -------------------------------------------
Again, this test was performed with NO input signal. I can repeat this test as many times as necessary and results are similar.
I will try the test again by removing the top cover and/or using another fan blowing on the amp. I'd also like to measure some of the internal components that I cannot access with the cover installed.
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klinemj
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Post by klinemj on Mar 15, 2013 15:18:22 GMT -5
I'd watch the hottest ones. One is controlling....focus on those.
Mark
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Post by richardrc on Mar 15, 2013 16:35:03 GMT -5
Great info DR. Will be very interested to see if any of the T03P devices are running significantly warmer than the rest. The power consumption figures are right on the money as per Keith.
If you start in class A/B and flick the switch do you hear the click? I am curious what the relay in the middle of the board is for. I hope it is not used for a bias transition.
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Post by frenchyfranky on Mar 15, 2013 16:49:36 GMT -5
My last Forté Audio 1a pure class A 50wpc run idle between 130F to 140F measure on heatsinks.
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Post by ocezam on Mar 15, 2013 19:35:00 GMT -5
My amps are here, but with the plans I have I won't even be able to play with them until at least Wednesday. This situation has me VERY CONCERNED. There's no doubt in my mind Dark Ranger's amp is cycling (AUDIBLY! not "seemlessly") out of class A mode prematurely. I thought when they were building this it should be in a 3 RU chassis (still smaller than the XPA-1) and use the space for heatsinks. Although at the recorded temps that Dark Ranger is reporting, I think it should be staying in class A anyway.
There should be some other's reporting there experiences before me. I certainly hope for the best.
Why didn't I wait for some reviews before I bought these?
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Post by creimes on Mar 15, 2013 19:38:44 GMT -5
I'm not even super concerned about the Class A, it is a nice touch but I for one like the overall build and power specs of these amps, maybe one day I will be able to grab a set but for now need to keep my $$ for the XMC that I'm on the list for.
Chad
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klinemj
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Post by klinemj on Mar 15, 2013 19:57:45 GMT -5
ocezam - don't fret...just try them...see what you find out and report back.
Mark
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