Pauly
Emo VIPs
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Post by Pauly on Dec 6, 2011 18:27:12 GMT -5
I saw that Bob. I was just telling him to maybe get yet another one shipped out to him.
But like I said, I think it's time for him to move on and try something else. I know that's what I'm going to do if they can't fix the hum in my XPA-5. It's not worth the headache. I'd rather pay more and get an amp that functions properly, instead of going through multiple amp swaps and phone calls to tech support.
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Deleted
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Post by Deleted on Dec 6, 2011 18:34:43 GMT -5
Neekos, I was simply asking straight up here. I am very sensitive when it comes to critical advice that are on a personal level. In particular when there is no valid reason for it. I'm not sure what you are talking about. I am leaving my response as is. I have seen or heard of people really screwing up electronics and at times getting some serious shock from attempting a fix when it's over their head. It's a word of caution, that's all. I've been around long enough to have seen some attempts at trying to remedy a problem and making the matter worse.
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NorthStar
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"And it stoned me to my soul" - Van Morrison
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Post by NorthStar on Dec 6, 2011 18:35:33 GMT -5
Pauly, that is one solution, that I can see. But in my own experience with hum issues in the past, I've always prefered to check all venues possible. And that is why I'm here to help other people like Frank. Hum is a funny thing, and it comes from various sources... And more often than not it can be fixed. Electricity is the power of our electronics; so is television, and cable, and Hollywood, and all that Jazz...
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Deleted
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Post by Deleted on Dec 6, 2011 18:43:38 GMT -5
That is one solution, that I can see. But in my own experience with hum issues in the past, I always prefer to try all venues possible. And that is why I'm here to help other people like Frank. Hum is a funny thing, and it comes from various sources... And more often than not it can be fixed. Electricity is the power of our electronics; so is television, and cable, and Hollywood, and all that Jazz... If it were me, and I was in Frank's position, I would get someone to assist me in my home. Like an electrician. Hum is a *bleep* to figure out sometimes. In my experience, it's been either the source (cable, satellite, etc..) or internal wiring, and most of the time a ground issue. That's why cheater plugs solve the issue majority of the time.
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NorthStar
Seeker Of Truth
"And it stoned me to my soul" - Van Morrison
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Post by NorthStar on Dec 6, 2011 18:44:01 GMT -5
Neekos, sorry if you found my tone less than perfect.
I don't have any problemo with you or -RW- for that matter. I simply suggested some good solution to Frank our OP that's all!
But -RW- mentioned "non-sense" regarding my solution. And you mentioned that "it is not wise for me to...".
You guys are free to express your opinions, and disagree with my recommendation ('simple tried' suggestion). Hope you can see the true light.
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NorthStar
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"And it stoned me to my soul" - Van Morrison
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Post by NorthStar on Dec 6, 2011 18:45:50 GMT -5
I thought that 'cheater plugs' were not recommended by professional electricians!
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Deleted
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Post by Deleted on Dec 6, 2011 19:19:05 GMT -5
Wise guy...I didn't say I condone them. it's used as a tool to diagnose a problem..
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NorthStar
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Post by NorthStar on Dec 6, 2011 20:12:56 GMT -5
Ah OK, sounds better now! ;D
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Post by fc911c on Dec 7, 2011 11:28:12 GMT -5
Hi everyone
First I would like to thank everyone for there suggestions and there help. That said I really don't want to monkey around inside the amp, and honestly I feel I shouldn't have too. I have done some further testing and talked to some very knowledgeable people concerning the hum issue. It seems that the input grounds are floating or have a high impedance to power ground, thus making them very sensitive to what they are connected too and what is used to connect them. If I connect an IC to the input and short the other end the hum is gone. Why some don't have problems and some do, I don't know. In my situation I would have to replace all my IC's, a total of 16+ just to make the amp quiet hopefully. I have not experienced this with any other amps I own or have tried. I am not saying the amps are not good it's just the way they are designed I believe, and may not work for everyone or every application. I thought I would mention this not to knock the amp, as I very much like most of what it does, but just to help others in this situation and head them in the right direction. One other thing I found out, with some IC's is, that a lot of times it's the ground part of the RCA connector causing the problem (too loose not a good contact).
I am still undecided on what I am going to do right now. So at this time I see no reason calling tech support and have new units sent out, as there is no guarantee I wont have the same problem, especially after receiving two already with similar behavior. When they go back I hope I wont have to pay the return charge because I feel in my situation it's not a question of not liking the way they sound, its what I feel are possibly defective units. I am very happy with the USP-1 and that's a keeper. Another option may be XPA-3's, as there doesn't seem to be a problem with humming in those as far as I can tell. I can get by with six instead of ten channels for my application.
Frank
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NorthStar
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"And it stoned me to my soul" - Van Morrison
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Post by NorthStar on Dec 7, 2011 14:54:11 GMT -5
Thanks Frank; you just touched the main point.
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Post by roadrunner on Dec 7, 2011 16:24:40 GMT -5
Frank, You said, "If I connect an IC to the input and short the other end the hum is gone." This is one of the standard test to check for ground loop hum, and since shorting the other end of the IC cured the hum you have shown that you very likely have a difference in gound potental somewhere in your connected equipment. Calling Emotiva's Tech Support can help you isolate what is causing the ground loop. There is still a slight possibility you have a defective amp, but it is unlikely to be you root cause. There are many other possible causes of hum. Decorative lighting, dimmer switches, flourescent lights, worn/defective wall outlets, defective cables, running IC parallel to AC power cords, etc are some of the more common sources. Emotiva supplies Tech Support personnel to assist customers and they are generally very knowledgable and will walk you thru the steps to find out what is happening. You have already paid for their expertise, you may as well take advantage of it.
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Post by fc911c on Dec 7, 2011 17:30:38 GMT -5
Frank, You said, "If I connect an IC to the input and short the other end the hum is gone." This is one of the standard test to check for ground loop hum, and since shorting the other end of the IC cured the hum you have shown that you very likely have a difference in ground potential somewhere in your connected equipment. Calling Emotiva's Tech Support can help you isolate what is causing the ground loop. There is still a slight possibility you have a defective amp, but it is unlikely to be you root cause. There are many other possible causes of hum. Decorative lighting, dimmer switches, fluorescent lights, worn/defective wall outlets, defective cables, running IC parallel to AC power cords, etc are some of the more common sources. Emotiva supplies Tech Support personnel to assist customers and they are generally very knowledgeable and will walk you thru the steps to find out what is happening. You have already paid for their expertise, you may as well take advantage of it. Thanks for your input. I have tried the amp in another home same thing hum, I have tried the amp alone with just the speakers connected and two IC's not even connected to anything, nothing else plugged in, nothing running still have hum. Correct me if I am wrong, if nothing is connected and the amp itself has no ground pin in the IEC plug socket how could it be a ground loop. I connect my scope to the outputs on all my amps in the same place the xpa-5 is and I get a nice clean trace and they all have ground pins on the amp. I do the same test on the XPA-5 both of them, and the output shows a trace with much noise. I cant see how 4 other amps work fine and these two dont, it just doesn't make sense to me. Also it's not like I am the only one having this problem. Where am I going wrong here?? Thanks Frank
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Post by fc911c on Dec 7, 2011 17:55:01 GMT -5
I saw that Bob. I was just telling him to maybe get yet another one shipped out to him. But like I said, I think it's time for him to move on and try something else. I know that's what I'm going to do if they can't fix the hum in my XPA-5. It's not worth the headache. I'd rather pay more and get an amp that functions properly, instead of going through multiple amp swaps and phone calls to tech support. Hi, good advise thanks btw did your's hum from the start or did it develope it later on, was it a vibration or in the speakers? Frank
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choirbass
Sensei
Sierra-2 DC-1 UMC-1 UPA-7
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Post by choirbass on Dec 8, 2011 4:43:56 GMT -5
Not to derail the thread, just to concur that I 'suppose' there's the same problem here too.. now what I'm not sure of is if it's hum or not. It's certainly not as audible as the avr used as as a pre-amp that was connected to the upa-7.. that was just plain noisy in comparison to being used as an 'all in one'. Tons more than when I shortly after upgraded to a umc-1. The umc-1 is practically dead silent in comparison through the speakers. Back on topic, I can only attribute the additional 'silent noise' to amp sensitivity. You can hear the electrical noise coming from the amp itself, especially when up close. And when you turn it off, the silent electrical hum from the speakers and amp stops. Although, 'it is what it is'.. An excellent amp, with its own trade offs, much like everything. Again, whether that's the hum being referred to or not, dunno. Come to think of it, the speakers being sensitive themselves doesn't really help the electrical noise either. So I dunno.. Anyhow
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Pauly
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Post by Pauly on Dec 8, 2011 12:41:14 GMT -5
I saw that Bob. I was just telling him to maybe get yet another one shipped out to him. But like I said, I think it's time for him to move on and try something else. I know that's what I'm going to do if they can't fix the hum in my XPA-5. It's not worth the headache. I'd rather pay more and get an amp that functions properly, instead of going through multiple amp swaps and phone calls to tech support. Hi, good advise thanks btw did your's hum from the start or did it develope it later on, was it a vibration or in the speakers? Frank Frank, my transformer has been humming from day one for over a year. I also have some hum in my speakers. Mainly in the left main. The tranny hum/buzz isn't super loud, but I can hear it from my listening seat which is 12' away. I plan on sending it to Emo after the holidays, and hopefully it will be fixed.
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Post by fc911c on Dec 8, 2011 12:59:02 GMT -5
Thanks for the reply, I hope you can get it straighten out.
Frank
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Pauly
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Post by Pauly on Dec 8, 2011 13:02:19 GMT -5
Likewise, Frank. Good luck.
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Post by SuBXeRo on Dec 9, 2011 10:36:39 GMT -5
I have a hum issue as well and have noticed it especially with my rf-7's more than any other speaker i have owned but it has been present in any speaker i have tried. I have finally gotten irritated enough that this weekend i am doing a final series of troubleshooting as i have done some rather in depth ones in the past to ensure i dont have a ground loop issue.
I have tested with both my rotel, marantz and HK receivers and all the speakers are dead silent so i am ruling the speakers out being defective 100%. I am hoping that the UMC-1 is not introducing noise, i dont think it is and i have all shielded emo rca interconnects and shielded HDMI cords from monoprice. My tests will consist of being isolated from from any cable tv connection. I also had my amp tested by emotiva about 6-7 or 8 months to ensure it tested out as it should and everything was in spec and the noise i had then i still have now.
I have come to the conclusion, as of now, without my last round of tests that this amp is not fully refined when it comes to its noise floor. It is alot of power to have and i cannot complain about the sound quality and performance that it has given me. as i have been extremely impressed with those aspects. IMO, amps wheather low power, high power or part of a receiver, should be dead silent...like my HK and Rotel. If you know that 200 watts a channel is going to create a noise floor that is high, find a way to make it not.
If my tests come out to where the amp is 100% the issue, i am going for biamping all around with amps that are around 100-125 watts a channel in the hopes that the lower channel wattages will help with lower noise floors. Unfortunately i am going with a different brand as i just have a bad taste in my mouth about this all. I do love Emotiva, they have excellent customer service, great subs, the UMC-1 has come such a long way and i love it especially comparing it agaisnt some receivers functionality.
I will keep you informed as to how my tests go.
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NorthStar
Seeker Of Truth
"And it stoned me to my soul" - Van Morrison
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Post by NorthStar on Dec 9, 2011 13:25:27 GMT -5
Some amps hum more than others...
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Post by fantaxp7 on Dec 9, 2011 15:00:20 GMT -5
SO I am hearing a hum, assuming it is the same issue.
I should check to see if moving a coax cable fixes it, and if it does fix it I should buy a ground loop isolator?
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