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Post by Gary Cook on Jan 19, 2014 21:53:55 GMT -5
Swap the speaker cables with a known good one, preferably really short, that means moving a speaker close to the amp or vice versa. Only have one speaker and swap it's connection to all channels of the amp. Gary, on the first test, should all 5 RCA input cables be connected to the amp? Should a source device being outputting audio to the receiver, and thus to the amp? I mostly start with all channels connected, then disconnect them one at a time and see if it makes any difference to the noise level. Reverse is also OK, start with none and then connect them one at a time. It's just a simple process of elimination, taking each possible source out of the system, one by one, until the source is either identified or there is only one possibility left. With s 5 channel power amp, 5 interconnects, 5 speaker cables, 5 speakers and a 5 channel source there are a lot of possibilities. It can also be a combination, perhaps one channel of the amp with one interconnect, one source channel and one speaker cable and they don't all have to be the same channels. I've had one speaker cable act as antenna for EMF and spread the noise around the other channels, it is unusual though these days the channels are pretty well isolated. Cheers Gary
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rontj
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Post by rontj on Jan 19, 2014 22:20:39 GMT -5
Emotiva, if I take my XPA-5, unplug all 5 RCA signal cables, and power cycle it, after it runs through the test (red light moves across all 5 channels from left to right), do you expect a brief 1/2 second hiss to come from all speakers? Do you expect me to hear any light hissing and/or hum that can be heard only from about up to 2 feet away from a speaker? Or do you expect all to be stone quiet?
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Post by garbulky on Jan 19, 2014 22:33:48 GMT -5
The hiss is normal behavior. As long as the hiss is not crazy loud.
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rontj
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Post by rontj on Jan 19, 2014 22:36:42 GMT -5
Gary, on the first test, should all 5 RCA input cables be connected to the amp? Should a source device being outputting audio to the receiver, and thus to the amp? I mostly start with all channels connected, then disconnect them one at a time and see if it makes any difference to the noise level. Reverse is also OK, start with none and then connect them one at a time. It's just a simple process of elimination, taking each possible source out of the system, one by one, until the source is either identified or there is only one possibility left. With s 5 channel power amp, 5 interconnects, 5 speaker cables, 5 speakers and a 5 channel source there are a lot of possibilities. It can also be a combination, perhaps one channel of the amp with one interconnect, one source channel and one speaker cable and they don't all have to be the same channels. I've had one speaker cable act as antenna for EMF and spread the noise around the other channels, it is unusual though these days the channels are pretty well isolated. Cheers Gary Well, and you mentioned only one 5-channel source, but we actually have several multi-channel sources, right? For my sources - TiVo (5 channels), PS3 (5 channels), OPPO (5 channels), Sonos (2 channels), receiver media streamer (5 channels). I've never paid attention, but it may be only one or two of these sources. I need to dedicate several hours for methodical testing, and see what I see. Thanks for your help.
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rontj
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Post by rontj on Jan 19, 2014 22:41:56 GMT -5
The hiss is normal behavior. As long as the hiss is not crazy loud. I'd be surprised if Emo answers this way. Some guys (Gary above) are saying their systems are stone silent, so some hissing therefore cannot be normal behavior. I can't imagine that Emo would release a product with hissing, and find that acceptable. Part of my test will be to reconnect my amp to my receiver and compare the hissing that I'm hearing with my amp. This test will eliminate the amp itself, as well as the 5 RCA interconnect cables.
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rontj
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Post by rontj on Jan 19, 2014 23:42:15 GMT -5
Gary, on the first test, should all 5 RCA input cables be connected to the amp? Should a source device being outputting audio to the receiver, and thus to the amp? I mostly start with all channels connected, then disconnect them one at a time and see if it makes any difference to the noise level. Reverse is also OK, start with none and then connect them one at a time. It's just a simple process of elimination, taking each possible source out of the system, one by one, until the source is either identified or there is only one possibility left. With s 5 channel power amp, 5 interconnects, 5 speaker cables, 5 speakers and a 5 channel source there are a lot of possibilities. It can also be a combination, perhaps one channel of the amp with one interconnect, one source channel and one speaker cable and they don't all have to be the same channels. I've had one speaker cable act as antenna for EMF and spread the noise around the other channels, it is unusual though these days the channels are pretty well isolated. Cheers Gary I can reconnect my speakers to my receiver, thus eliminating the amp and the 5 RCA interconnects, and compare the low-level hissing and hum to what I'm hearing now, from the same 5-channel source, i.e., OPPO. If it's quiet, that tells me right there the problem is one or more of the interconnects, or the amp. Then, it's easy to test the interconnects. Of course, if this test shows the same level of hiss/hum, then assuming the causes of the hiss/hum are additive, then that likely suggests the amp and interconnects are clean, and I need to test other sources (speaker cable, speakers, EMF interference).
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Post by wolffcub on Jan 19, 2014 23:56:21 GMT -5
I just bought 5 XPA-100 amps last month and during the power up stage the speakers just hiss for a fraction of a second then go quiet again. If you put your ear right touching the highs you can hardly make out a hiss. I have a hard time trying to hear every time between testing for the fun of it after reading all the posts above.
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Post by garbulky on Jan 20, 2014 0:42:38 GMT -5
The hiss is normal behavior. As long as the hiss is not crazy loud. I'd be surprised if Emo answers this way. Some guys (Gary above) are saying their systems are stone silent, so some hissing therefore cannot be normal behavior. I can't imagine that Emo would release a product with hissing, and find that acceptable. Part of my test will be to reconnect my amp to my receiver and compare the hissing that I'm hearing with my amp. This test will eliminate the amp itself, as well as the 5 RCA interconnect cables. I meant the first half second hiss. Also if your speakers are reasonably efficient and you put your ears near the tweeters there is a slight hiss which is reduced if you unplug the RCA cables. But from listening positioning or more than 4-5 feet away - it should be silent. Unless your amps is really bothering you audibly, it sounds to me like you are describing a normal situation especially if your cables are very long.
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rontj
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Post by rontj on Jan 20, 2014 1:58:56 GMT -5
I'd be surprised if Emo answers this way. Some guys (Gary above) are saying their systems are stone silent, so some hissing therefore cannot be normal behavior. I can't imagine that Emo would release a product with hissing, and find that acceptable. Part of my test will be to reconnect my amp to my receiver and compare the hissing that I'm hearing with my amp. This test will eliminate the amp itself, as well as the 5 RCA interconnect cables. I meant the first half second hiss. Also if your speakers are reasonably efficient and you put your ears near the tweeters there is a slight hiss which is reduced if you unplug the RCA cables. But from listening positioning or more than 4-5 feet away - it should be silent. Unless your amps is really bothering you audibly, it sounds to me like you are describing a normal situation especially if your cables are very long. Thanks for that clarification. Typical listening room my speakers are 94 dB, 92 dB anechoic chamber. If the slight hiss/hum were equal on all 5 speakers, I'd probably let it ride, but it's not. I've not yet checked my surround right speaker, but with the remaining 4, the 8-year old 12 awg are louder than the 1-2 year old 10 awg speaker cable. That could be the cause, right there. Perhaps the 12 awg is picking up more EMF interference. But you're right in general, I cannot hear anything from the listening position.
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rontj
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Post by rontj on Jan 20, 2014 2:02:34 GMT -5
I just bought 5 XPA-100 amps last month and during the power up stage the speakers just hiss for a fraction of a second then go quiet again. If you put your ear right touching the highs you can hardly make out a hiss. I have a hard time trying to hear every time between testing for the fun of it after reading all the posts above. Nice power for your speakers! Well, that's more or less what I'm experiencing, hissing for a fraction of a second at power up stage, then quiet at the listening position. But, my 5 speakers are not producing the same level of hiss/hum, so I need to do some testing. I also want to hear Emo's response as to whether or not they expect their amps to have a fraction-of-a-second hiss at power up.
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rontj
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Post by rontj on Jan 20, 2014 5:09:12 GMT -5
Update: I actually can hear the speakers from the primary listening position with the source paused. Somehow the center speaker is quietest, with the left being the loudest. Sounds like a high powerline static. Need to find the cause, and I will. Not something I can live with, now that I've spent a little more time investigating; I'm certainly getting unwanted interference.
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emovac
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Post by emovac on Jan 20, 2014 14:07:41 GMT -5
The AT speaker position hiss is something the manufacturer will state is within specification. My Parasound stuff, and other brand equipment I have had that same noise. At 4-5 feet from the speaker, it's an issue. First step is to check for ground loops. If at all possible, power everything from the same circuit. Make sure no dimmers, or refrigerators/motors share the same circuit. Go to radio shack and buy one of these: www.radioshack.com/product/index.jsp?productId=2062214Try to cleanup your wiring/cabling and it may prove wise to replace your cables with a spare(s) one by one. It's a long shot, but a good place to start if the above doesn't work. Attachments:
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Post by aud on Jan 20, 2014 19:00:57 GMT -5
Update: I actually can hear the speakers from the primary listening position with the source paused. Somehow the center speaker is quietest, with the left being the loudest. Sounds like a high powerline static. Need to find the cause, and I will. Not something I can live with, now that I've spent a little more time investigating; I'm certainly getting unwanted interference. Hi rontj, just read your last post above. Things have become much worse I think I can safely say. This has led me to respond with a whole new approach which I know can sometimes be more deleterious than helpful but I've decided to ask you this because you are now hearing uneven noise from the listening chair and you sound very frustrated and rightfully so. The surround sound receiver you talk about, what mode was it set at when the above occurred. Pro Logic IIx, DTS, no mode, etc. and I apologize before hand, but I forgot what sources you are using. Computer based, Blu Ray player, CD player etc. ? Hopefully this line of questioning is all mute because Emo Support got the problems resolved already.
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lockon
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Post by lockon on Jan 21, 2014 10:38:48 GMT -5
If you can't hear it from your listening position, don't worry about it too much. My Old Parasound Halo amps used to have a low emission hum, but you had to be near {at} the speakers to hear it. If you put your ear against the speaker and hear a low rumble, that is not unusual. If it is distracting, you'll need to figure it out. Might clean up your wiring and make sure the power circuit you are using isn't dirty. [Dimmers, motors, etc]. In my case I had a very low level buzz from the speakers. It turned out to be a dimmer in a wall box where the power for the outlets also apparently ran through. I bypassed the dimmer and the problem disappeared. The amp with all interconnects connected to the UMC-200 is stone cold quiet without source material running (or on mute). My 18 year son says he can hear a faint high frequency white noise with his ear right on the tweeter (B+W CL5) but I can't hear it with my old ears. Sunil
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Deleted
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Post by Deleted on Jan 21, 2014 13:55:47 GMT -5
Test to see if it is ground loop problem. Hiss can be normal to an extent. Hum, or hum+hiss may not. Test 1: Take the 3-prong plug from your power amp cable and plug it into a 3 to 2-prong adapter. This removes the ground from the circuit. (These are usually light gray in color and can be purchased for less that a dollar if you don't already have one.) Plug it into the wall. If the buzzing/humming sound stops them you have a ground loop problem and your ground is connected in the outlet in this case. Test 2: If there is no change from doing Test 1, then there may not be a ground wire, or the ground wire may not hooked up, in your outlet. Test to see if the ground is present by using a circuit tester. I used the small yellow type with indicator lights: www.amazon.com/GE-50542-3-Wire-Receptacle-Tester/dp/B002LZTKIA/ref=sr_1_3?ie=UTF8&qid=1390329899&sr=8-3&keywords=circuit+testerIf the tester is not showing the ground as connected therein may be your problem. With an extension cord test in different outlets around your room. This was strange but in testing outlets in my living room I found two ungrounded outlets in my house. Inexplicably, one was dead quiet with my power amp plugged in while the other was noisy.
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Deleted
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Post by Deleted on Jan 21, 2014 14:01:13 GMT -5
I forgot to mention that I have found that refrigerators, fluorescent tube lights, and anything with a fan in it in particualar, if on the same circuit as your power amp, can generate 60 cycle hum.
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rontj
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Post by rontj on Jan 22, 2014 0:53:18 GMT -5
The AT speaker position hiss is something the manufacturer will state is within specification. My Parasound stuff, and other brand equipment I have had that same noise. At 4-5 feet from the speaker, it's an issue. First step is to check for ground loops. If at all possible, power everything from the same circuit. Make sure no dimmers, or refrigerators/motors share the same circuit. Go to radio shack and buy one of these: www.radioshack.com/product/index.jsp?productId=2062214Try to cleanup your wiring/cabling and it may prove wise to replace your cables with a spare(s) one by one. It's a long shot, but a good place to start if the above doesn't work. Thanks for this suggestion. I'll keep it in mind. I've not yet had a chance to thoroughly review and attempt to identify the cause of my static/hiss/hum, but am confident I'll find the cause. I'll keep this product in mind. It connects in-line between receiver and amp? What does AT stand for? I do have all equipment powered on a dedicated 20A circuit, with no dimmers on that one circuit. I do have a dimmer in the room, though it's on a separate 15A circuit. Cabling is 80% clean. I could tighten it up a bit, but not much. No power cables are running parallel to any signal cables, certainly. Seems that the most revealing first test to perform is to reconnect the speakers to the receiver, and listen to the speakers. If they are much quieter, then the cause of the current static/hiss/hum must be either the 5 RCA interconnects, or the amp.
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rontj
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Post by rontj on Jan 22, 2014 1:02:12 GMT -5
Update: I actually can hear the speakers from the primary listening position with the source paused. Somehow the center speaker is quietest, with the left being the loudest. Sounds like a high powerline static. Need to find the cause, and I will. Not something I can live with, now that I've spent a little more time investigating; I'm certainly getting unwanted interference. Hi rontj, just read your last post above. Things have become much worse I think I can safely say. This has led me to respond with a whole new approach which I know can sometimes be more deleterious than helpful but I've decided to ask you this because you are now hearing uneven noise from the listening chair and you sound very frustrated and rightfully so. The surround sound receiver you talk about, what mode was it set at when the above occurred. Pro Logic IIx, DTS, no mode, etc. and I apologize before hand, but I forgot what sources you are using. Computer based, Blu Ray player, CD player etc. ? Hopefully this line of questioning is all mute because Emo Support got the problems resolved already. Hi Aud. Well, I wouldn't say they've become worse, it's just that I'm paying more attention than I have in the past, and getting a proper and accurate description of the problem. Frustration level is minor, as I've not yet begun trying to find the cause, but am confident I'll find it when I put aside the time needed to devote to this problem. The static/hiss/hum has likely always been uneven, I'm just not been aware of it. Re: the listening mode, I'd say Dolby Digital. I don't use PLII, as I prefer to listen to two-channel sources in stereo. But this is a good question. Sources are PS3 (older, fat), TiVo, OPPO Blu-ray, Roku and Sonos. I've not yet identified whether there's any difference in static/hiss/hum in the 5 difference sources.
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rontj
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Post by rontj on Jan 22, 2014 1:03:59 GMT -5
If you can't hear it from your listening position, don't worry about it too much. My Old Parasound Halo amps used to have a low emission hum, but you had to be near {at} the speakers to hear it. If you put your ear against the speaker and hear a low rumble, that is not unusual. If it is distracting, you'll need to figure it out. Might clean up your wiring and make sure the power circuit you are using isn't dirty. [Dimmers, motors, etc]. In my case I had a very low level buzz from the speakers. It turned out to be a dimmer in a wall box where the power for the outlets also apparently ran through. I bypassed the dimmer and the problem disappeared. The amp with all interconnects connected to the UMC-200 is stone cold quiet without source material running (or on mute). My 18 year son says he can hear a faint high frequency white noise with his ear right on the tweeter (B+W CL5) but I can't hear it with my old ears. Sunil Glad you found the cause. Did the dimmer cause a buzz when the dimmer was at 0%, or only when above 0%?
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hemster
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Post by hemster on Jan 22, 2014 1:16:08 GMT -5
Buzz induced from lighting dimmer switches is Triac or SCR noise leaking into the audio equipment chain. This can occur when the power for both the light and audio gear is drawn from the same circuit or phase of mains electrical power. It can also occur due to induction due to proximity. Some dimmers are better than others. RFI is induced due to sharp spikes of current. Dimmer chokes and filters can help alleviate this issue.
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