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Post by DavidR on Jun 29, 2014 19:03:08 GMT -5
My experience was you really need to feed audio and video from separate power receptacles/circuits.
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KeithL
Administrator 
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Post by KeithL on Jun 30, 2014 11:24:39 GMT -5
I want to remind you of something - which may or may not be relevant in this discussion - but seems to be a common misconception. Noise level must ALWAYS be considered in comparison to signal level... and that is much more important with a phono signal. Phono preamps need to have a MUCH higher gain than line stages, so a phono input or preamp will USUALLY be 20 dB to 30 dB noisier than a line level input. This is one of the limitations/drawbacks of vinyl - records vary widely, but rarely have a S/N above 60 dB or 70 dB (if even that). If you turn up the level enough, you will USUALLY hear hiss from a phono input; this is normal. It's only important if, at a certain setting, the phono preamp or input actually makes MORE noise than the record surface noise at that volume setting. So, forget things like "it makes noise when I set the Volume control to xyz".... Play a record reasonably loudly, and note the amount of hiss you hear and the volume setting. Now listen to how much hiss you hear AT THE SAME VOLUME SETTING, but with the arm lifted and the record stopped. If you hear significantly more hiss when the record is playing than when it's not playing, then the surface noise on the record is greater than the hiss on your preamp or phono input. If that's the case, then your phono input or preamp is as quiet as it needs to be. Hey Keith, Thanks for your response, we have actually talked on the phone about my XSP-1 Home theater bypass hum. I am planning to re-arrand my audio rack, and when I do I will move all power cables to the left side the rack and all interconnects to the right, I guess I will then run the HDMI cables down the center of the rack. I use a Ferman 15 pfi, so everything should be grounded at about the same ground point, and my plasma screen is plugged into that unit in the video block. So to try and give some help: When just using the XSP-1. Balanced from my dac through the asp-1, to the sub and xpa-2 is more or less fine. At full volume I get a slight bit more noise then at any other volume level but this happened when I moved my cables around so I feel like if I re-cable that will go away. On the phono pre, I get noise at about -30 with nothing playing, and it is noticeable from my listening seat at -25. With music playing it is fine to about -22, though I never have an erg to play louder. When I run the dac into the xsp-1 and then out via processor loop to my headphone amp, I get no noise as long as the amp is plugged in via a cheater plug (bad practice I know, but I have no choice it seems). The problem really sits in my Home theater portion. I have slight noise coming through all speakers that run from the 7701 to the UPA-500, but that is not audible till about +2 on the volume scale from the listening position. I then when switching my XSP-1 to HTB mode, have noise from the 7701->XSP-1->XPA-2 that is much louder by comparison to the noise coming from all other speakers. I still cannot here this noise from my listening seat until +2 and the noise does not seem to vary with volume till we get to +2. This noise has what sounds like a 60hz hum as a part of the overall noise coming out of it. Things going into the 7701 is a PC via HDMI (3 prong), apple tv via HDMI(3 prong), att cable box via HDMI (2 prong). All connectors from the 7701 are RCA for the pre-outs. |
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Post by me262 on Jul 1, 2014 14:04:22 GMT -5
That is a good point, and I have noticed that I do not here his when actually playing my records so that is good. I still would like to figure out whats going on with my 7701 and why it is producing noise but it appears I may be doomed forever on that one. Thanks everyone for the help and re-assurance.
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Deleted
Deleted Member
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Post by Deleted on Jan 24, 2015 22:08:23 GMT -5
i have the same exact problem.
I've narrowed that the hum is being produced form my local cable TV provider.
Any recommendations?
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Post by Gary Cook on Jan 24, 2015 22:25:56 GMT -5
Does the cable box have an earth pin on the power cable?
If so, do you have another cable without earth p[in that you can try?
Cheers
Gary
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Post by deltadube on Jan 24, 2015 22:37:18 GMT -5
Does the cable box have an earth pin on the power cable? If so, do you have another cable without earth p[in that you can try? Cheers Gary hi Gary .. is that what we call the ground pin in north America.. ? on a 3 prong plug.. lower middle is ground.. thanks.. |
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Post by Gary Cook on Jan 24, 2015 22:38:03 GMT -5
Does the cable box have an earth pin on the power cable? If so, do you have another cable without earth p[in that you can try? hi Gary .. is that what we call the ground pin in north America.. ? on a 3 prong plug.. lower middle is ground.. thanks. That's it. Cheers Gary |
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Post by ansat on Jan 25, 2015 10:28:06 GMT -5
i have the same exact problem. I've narrowed that the hum is being produced form my local cable TV provider. Any recommendations? Try disconnecting the cable from the cable box, this will determine if the hum is hardware related or being picked up outside from the power lines. Tony |
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Deleted
Deleted Member
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Post by Deleted on Jan 25, 2015 22:15:03 GMT -5
i have the same exact problem. I've narrowed that the hum is being produced form my local cable TV provider. Any recommendations? Try disconnecting the cable from the cable box, this will determine if the hum is hardware related or being picked up outside from the power lines. Tony When the coaxial cable is removed from the cable TV receiver set top box inlet the hum is completely gone. Any recommendations? |
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Deleted
Deleted Member
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Post by Deleted on Jan 25, 2015 22:16:55 GMT -5
hi Gary .. is that what we call the ground pin in north America.. ? on a 3 prong plug.. lower middle is ground.. thanks. That's it. Cheers Gary There's no a Earth pin ground. When the coaxial cable is removed from the cable TV receiver set top box inlet the hum is completely gone. Any recommendations? |
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Post by ansat on Jan 25, 2015 22:25:03 GMT -5
Try disconnecting the cable from the cable box, this will determine if the hum is hardware related or being picked up outside from the power lines. Tony When the coaxial cable is removed from the cable TV receiver set top box inlet the hum is completely gone. Any recommendations? Check the ground where the cable enters the building. (Usually a grey box outside the building) there should be a ground at the barrel connector. Ensure that is grounded well. Other then that, you will need a filtration that can pass digital cable. Tony |
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Deleted
Deleted Member
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Post by Deleted on Jan 25, 2015 23:03:19 GMT -5
When the coaxial cable is removed from the cable TV receiver set top box inlet the hum is completely gone. Any recommendations? Check the ground where the cable enters the building. (Usually a grey box outside the building) there should be a ground at the barrel connector. Ensure that is grounded well. Other then that, you will need a filtration that can pass digital cable. Tony I've checked the ground outside and it's intact and tight. What types of filtration is recommended? Thank you for the help |
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Post by ansat on Jan 25, 2015 23:24:43 GMT -5
Check the ground where the cable enters the building. (Usually a grey box outside the building) there should be a ground at the barrel connector. Ensure that is grounded well. Other then that, you will need a filtration that can pass digital cable. Tony I've checked the ground outside and it's intact and tight. What types of filtration is recommended? Thank you for the help You can try a ground loop isolator. But it could mess with your cable data speeds and or kill on demand content. The other option might be to call the cable company and see if they will dispatch at their cost. Other options, are if your not using digital output from the cable box to the receiver, then try that. If you are using digital, then you could see if using a different circuit could help (but even if that helps, it usually is not pretty solution). Since I have never had the problem I would not be sure what hardware to recommend. You might need to ping someone else who has gone through this or do some Google digging. Tony |
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Post by ansat on Jan 25, 2015 23:30:06 GMT -5
One more thought though. Call the cable company and have them run a line test to ensure that their loop is remote testing good. Also if you have enough cable in the house, you could bypass any splitters to ensure the coax splitters are not failing.
Tony
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Post by flamingeye on Jan 26, 2015 21:52:22 GMT -5
I had that problem and when I got a APC -10 power conditioner that also has connections for cable TV it curd my hum that I was getting from my dish network
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