Javs
Minor Hero
Posts: 15 
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Post by Javs on Feb 6, 2018 22:31:29 GMT -5
Hey Guys,
I recently bought a 5175 and even with zero inputs connected to the amp, and only one speaker connected, channel 1 exhibits a fairly loud buzzing sound which can be heard from across a quiet room. Move the speaker to channel 2, silent.
The first amp I immediately initiated an RA and they sent me a 2nd unit, the buzzing is about half as loud as before, but still only on channel 1.
All the other channels, 2, 3, 4, 5 are all WAY quieter on both the 5175's I have here, there is still very slight buzzing, and transformer hum heard (hum from the amp itself and the speakers), but I have to put my ear up to my 100+db/w tweeters to hear it, so I have no issues with that.
I feel like its either incredibly bad luck to have gotten two bad samples in a row, or there is something going on and it may be solvable?
I have tried taking the amp to a completely different section of my house with literally only a small bookshelf speaker, no inputs connected at all, nothing but the amp plugged right into the power socket (tried with and without power strips) and only one speaker output connected, to test and I still get very audible buzzing on channel 1, and the other channels almost silent. I feel this rules out any kind of input noise since there are none connected, the noise is also the same if I have wired the amp with 5x inputs from my Pre-pro. If the amp was buzzing on all channels I would think sure its probably a power issue in terms of ground loops or DC on the line (which is still possible), but wouldn't all channels then buzz and not exactly channel 1 on both amps?
Is there any reason why only one channel would buzz? the buzzing on channel 1 vs the others is probably 10x louder. Do I have two defective amps? Its a real shame, because this is a great amp, I am using an XPa7-Gen 2 and a Rotel 1555. The XPA7 also has transformer hum but is otherwise totally silent and has been reliable for me for the past two years..
The first sample, the buzzing was loud enough it was immediately obvious it was defective, the 2nd sample is half as loud, and actually I didnt notice it due to the noise floor at the time in my room until later, but sure enough, moved that speaker over to input 2 (since I am only using 4 chans on this amp anyway) and completely silent.
Any ideas guys?
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Post by rbk123 on Feb 7, 2018 23:06:35 GMT -5
Weird. Does it buzz if you have other speakers plugged into the other channels? Does it buzz if you have different speakers plugged into channel 1?
If the above is yes, I'd send it back again as well. You may tolerate it, but you'll always know and it could make reselling it later more difficult.
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Javs
Minor Hero
Posts: 15
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Post by Javs on Feb 8, 2018 17:54:47 GMT -5
Weird. Does it buzz if you have other speakers plugged into the other channels? Does it buzz if you have different speakers plugged into channel 1? If the above is yes, I'd send it back again as well. You may tolerate it, but you'll always know and it could make reselling it later more difficult. As I said, only channel 1 buzzes on both samples of the amp I have here. It buzzes the same weather I have 4 speakers plugged into the other four channels, or none. I have tried different actual speakers too, the same speak will buzz on channel 1, and not on 2 through 5. Those same speakers by the way are completely silent on my XPA-7 and even more silent on my Rotel RMB-1555, both of those amps also have torroidal transformers. So these 5175 are just spectacularly noisy compared to the other two amps I have. One Amp buzzes at least twice as loud as the other, Both amps buzz on all channels, but on both amps the buzzing on channels 2 through 5 is so low, that I would not even begin to consider it a fault, its so low I have to stick my ear almost in my tweeter. But channel 1 buzzing on both amps is audible from 6 ft away in a quiet room. I.E. unacceptable if its actually the fault of the amp itself. It seems like two amps buzzing could be more than a coincidence though. I am curious if for eg there was DC on the line in my house, would it be louder on channel 1 vs the others... does the amps power pass through each channel in sequence, or should the buzzing be on all channels equally if it is DC. I am hoping someone from Emotiva can comment on this, otherwise I need to return both amps. I dont want to keep trying new samples of the amp if there is a possibility of the above. I guess I need to take the amp somewhere off site and see if it does it at a different location. |
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Post by teaman on Feb 8, 2018 18:28:29 GMT -5
Sorry about your luck Javs. I know a buddy had to send his back for the over-heating issue but I have not heard about any buzzing from him....so it may not be across the board with all amps. I would definitely take the amp to a neighbor's or something if that is an option to rule out an internal wiring issue if that isn't too much trouble but I am guessing this is inherent to the amp itself...if not multiple amps. Hopefully KeithL or someone else from Emotiva can chime in.
Tim
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Post by leonski on Feb 8, 2018 18:40:18 GMT -5
You know it's not the speaker since the buzz stays with the channel.
Try swapping input cables between the various channels. If it follows a cable, THAT'S the issue.
Before doing an outright swap, you may try wiggling the cable on the channel in question. One bad 'pull' and it's a goner and needs to be replaced.
I find it a little unlikely that you got a bad amp with the SAME problem on the SAME channel 2x.
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Post by knucklehead on Feb 8, 2018 22:58:30 GMT -5
Hmm - what are the odds that 2 samples of this product had the same defect?
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Post by leonski on Feb 8, 2018 23:27:21 GMT -5
Hmm - what are the odds that 2 samples of this product had the same defect? Odds? I'll give you 50:1 and points. THAT kind of unlikely. |
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Post by adaboy on Feb 9, 2018 5:58:46 GMT -5
You know it's not the speaker since the buzz stays with the channel. Try swapping input cables between the various channels. If it follows a cable, THAT'S the issue. Before doing an outright swap, you may try wiggling the cable on the channel in question. One bad 'pull' and it's a goner and needs to be replaced. I find it a little unlikely that you got a bad amp with the SAME problem on the SAME channel 2x. OP tested this without any input cables, and same speaker wire used on working channels which rules out all cables. 🤙 |
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Post by Soup on Feb 9, 2018 6:53:04 GMT -5
Return it and move on. life is too short and there are many other great options.
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Post by leonski on Feb 9, 2018 12:35:47 GMT -5
You know it's not the speaker since the buzz stays with the channel. Try swapping input cables between the various channels. If it follows a cable, THAT'S the issue. Before doing an outright swap, you may try wiggling the cable on the channel in question. One bad 'pull' and it's a goner and needs to be replaced. I find it a little unlikely that you got a bad amp with the SAME problem on the SAME channel 2x. OP tested this without any input cables, and same speaker wire used on working channels which rules out all cables. 🤙 I must'a missed the input cable test: If so? Against all odds, OP got 2 amps with same problem in same channel. |
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Javs
Minor Hero
Posts: 15
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Post by Javs on Feb 9, 2018 16:37:24 GMT -5
Damn. All right. Amp goes back.
xpa-5 it is!
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Post by torifile on Feb 14, 2018 8:10:34 GMT -5
I’m having the same issue with 2 A-100’s. The issue for me is through the headphone jack, not the speakers, but 2 units having the same buzzing/hissing problem at all volume levels. It’s not the noise floor because if it were, I’m 100% sure the A-100 would be panned by anyone who heard it. It’s that loud and noticeable. I’ve done all the troubleshooting and testing to rule out outside noise. It’s not. It’s definitely the amp.
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Post by vneal on Feb 14, 2018 8:48:47 GMT -5
WARRANTY TIME --GET RGA
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Post by torifile on Feb 14, 2018 9:01:32 GMT -5
What’s RGA? I’m within my return period so it’s going back. I checked my speakers this morning. There is also a hissing/buzzing sound from them, though it’s faint. I’m not using them for critical listening so it doesn’t bother me nearly as much. |
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Post by rbk123 on Feb 14, 2018 9:46:37 GMT -5
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Post by goodfellas27 on Feb 14, 2018 10:05:45 GMT -5
It might be the WiFi router of your wireless phone interference the speaker pics up. It happened to me once and I had to move it.
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Post by torifile on Feb 17, 2018 0:55:39 GMT -5
It might be the WiFi router of your wireless phone interference the speaker pics up. It happened to me once and I had to move it. It happens in multiple locations with nothing else plugged in. It happened in my brick wall lined basement at least 10’ from anything but the outlet. |
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Post by leonski on Feb 17, 2018 3:08:26 GMT -5
I think vneal meant RMA, not RGA. Where I worked, an RGA was a Residual Gas Analyzer, used to troubleshoot high vacuum systems and as a quality monitor.
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Post by Soup on Feb 17, 2018 7:03:51 GMT -5
So how much additional $$$ spent on shipping the amp back twice will it cost you?...........................
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Javs
Minor Hero
Posts: 15
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Post by Javs on Feb 17, 2018 18:00:44 GMT -5
So how much additional $$$ spent on shipping the amp back twice will it cost you?........................... Zero. I live in Australia, I am actually a reseller, this is for a demo room. Even if I was an end user, it would cost zero. The excellent Australian Distributor is going out of their way to resolve this. I actually will be getting a 3rd 5175, I had the Distributor bench test the 3rd unit and they found no issues with the noise floor on that one, so fingers crossed its fine for me too. |
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