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#1
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60Hz hums
I don't know when this problem started, but I'm now having 60Hz hums from
all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! |
#2
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On Sun, 21 Nov 2004 00:09:24 -0500, KingMe wrote:
I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! freq peaks@60Hz and local max at harmonics other equips disconnected except synth+sblive+balanced equips: 1. synth 2. sblive 3. sblive w/synth unplugged (freq peak: -77dB@60Hz) see http://mkeroppi.com/60Hz.PNG balanced equip have same problem, but 100dB peaks (could even be the mixer)... |
#3
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On Sun, 21 Nov 2004 00:09:24 -0500, KingMe wrote:
I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! freq peaks@60Hz and local max at harmonics other equips disconnected except synth+sblive+balanced equips: 1. synth 2. sblive 3. sblive w/synth unplugged (freq peak: -77dB@60Hz) see http://mkeroppi.com/60Hz.PNG balanced equip have same problem, but 100dB peaks (could even be the mixer)... |
#4
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"KingMe" wrote in message news On Sun, 21 Nov 2004 00:09:24 -0500, KingMe wrote: I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! freq peaks@60Hz and local max at harmonics other equips disconnected except synth+sblive+balanced equips: 1. synth 2. sblive 3. sblive w/synth unplugged (freq peak: -77dB@60Hz) Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Peace, Paul |
#5
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"KingMe" wrote in message news On Sun, 21 Nov 2004 00:09:24 -0500, KingMe wrote: I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! freq peaks@60Hz and local max at harmonics other equips disconnected except synth+sblive+balanced equips: 1. synth 2. sblive 3. sblive w/synth unplugged (freq peak: -77dB@60Hz) Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Peace, Paul |
#6
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On Sun, 21 Nov 2004 07:30:14 GMT, Paul Stamler wrote:
Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Peace, Paul Thanks. You know what? It's cable+modem we've recently installed here. Is there any fixes? We don't want to be unplugging the cable everytime we want to record something, especially since we would have to do it at the outlet, or else open cable would still be spewing its stuff everywhere. |
#7
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On Sun, 21 Nov 2004 07:30:14 GMT, Paul Stamler wrote:
Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Peace, Paul Thanks. You know what? It's cable+modem we've recently installed here. Is there any fixes? We don't want to be unplugging the cable everytime we want to record something, especially since we would have to do it at the outlet, or else open cable would still be spewing its stuff everywhere. |
#8
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"KingMe" wrote in message
On Sun, 21 Nov 2004 07:30:14 GMT, Paul Stamler wrote: Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Peace, Paul Thanks. You know what? It's cable+modem we've recently installed here. Is there any fixes? We don't want to be unplugging the cable everytime we want to record something, especially since we would have to do it at the outlet, or else open cable would still be spewing its stuff everywhere. http://www.epanorama.net/documents/g..._isolator.html |
#9
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"KingMe" wrote in message
On Sun, 21 Nov 2004 07:30:14 GMT, Paul Stamler wrote: Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Peace, Paul Thanks. You know what? It's cable+modem we've recently installed here. Is there any fixes? We don't want to be unplugging the cable everytime we want to record something, especially since we would have to do it at the outlet, or else open cable would still be spewing its stuff everywhere. http://www.epanorama.net/documents/g..._isolator.html |
#10
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In article , KingMe wrote:
I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! You have a ground loop. Read the section in the FAQ on ground loops. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#11
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In article , KingMe wrote:
I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! You have a ground loop. Read the section in the FAQ on ground loops. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#12
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On Sun, 21 Nov 2004 07:30:14 GMT, Paul Stamler wrote:
Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Thanks. You know what? It's cable+modem we've recently installed here. Is there any fixes? We don't want to be unplugging the cable everytime we want to record something, especially since we would have to do it at the outlet, or else open cable would still be spewing its stuff everywhere. It's a ground loop, then. The cable modem should be plugged into a different circuit than your audio gear. You are running 10BaseT from the cable modem to the computer, so the fact that the power line ground and the cable ground on the cable modem are nasty, that doesn't matter because the 10BaseT line is balanced and has no reference ground, so it can't carry the ground loop on. My guess is that the third pin on the cable modem has tied your power line ground to the (very nasty) cable system ground and caused an instant loop. Take it somewhere else and run a long 10BaseT line. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#13
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On Sun, 21 Nov 2004 07:30:14 GMT, Paul Stamler wrote:
Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Thanks. You know what? It's cable+modem we've recently installed here. Is there any fixes? We don't want to be unplugging the cable everytime we want to record something, especially since we would have to do it at the outlet, or else open cable would still be spewing its stuff everywhere. It's a ground loop, then. The cable modem should be plugged into a different circuit than your audio gear. You are running 10BaseT from the cable modem to the computer, so the fact that the power line ground and the cable ground on the cable modem are nasty, that doesn't matter because the 10BaseT line is balanced and has no reference ground, so it can't carry the ground loop on. My guess is that the third pin on the cable modem has tied your power line ground to the (very nasty) cable system ground and caused an instant loop. Take it somewhere else and run a long 10BaseT line. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#14
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On 21 Nov 2004 10:30:37 -0500, Scott Dorsey wrote:
It's a ground loop, then. The cable modem should be plugged into a different circuit than your audio gear. You are running 10BaseT from the cable modem to the computer, so the fact that the power line ground and the cable ground on the cable modem are nasty, that doesn't matter because the 10BaseT line is balanced and has no reference ground, so it can't carry the ground loop on. My guess is that the third pin on the cable modem has tied your power line ground to the (very nasty) cable system ground and caused an instant loop. Take it somewhere else and run a long 10BaseT line. --scott I could go with this explanation, but the thing is there is no ground pins on the modem. But you would actually connect the modem+router+stuff "near" everything if you can't isolate them, but since they don't carry ground loops in any case, it doesn't matter. |
#15
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On 21 Nov 2004 10:30:37 -0500, Scott Dorsey wrote:
It's a ground loop, then. The cable modem should be plugged into a different circuit than your audio gear. You are running 10BaseT from the cable modem to the computer, so the fact that the power line ground and the cable ground on the cable modem are nasty, that doesn't matter because the 10BaseT line is balanced and has no reference ground, so it can't carry the ground loop on. My guess is that the third pin on the cable modem has tied your power line ground to the (very nasty) cable system ground and caused an instant loop. Take it somewhere else and run a long 10BaseT line. --scott I could go with this explanation, but the thing is there is no ground pins on the modem. But you would actually connect the modem+router+stuff "near" everything if you can't isolate them, but since they don't carry ground loops in any case, it doesn't matter. |
#16
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On Sun, 21 Nov 2004 06:49:46 -0500, Arny Krueger wrote:
"KingMe" wrote in message On Sun, 21 Nov 2004 07:30:14 GMT, Paul Stamler wrote: Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Peace, Paul Thanks. You know what? It's cable+modem we've recently installed here. Is there any fixes? We don't want to be unplugging the cable everytime we want to record something, especially since we would have to do it at the outlet, or else open cable would still be spewing its stuff everywhere. http://www.epanorama.net/documents/g..._isolator.html Thanks, we'll try this. |
#17
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On Sun, 21 Nov 2004 06:49:46 -0500, Arny Krueger wrote:
"KingMe" wrote in message On Sun, 21 Nov 2004 07:30:14 GMT, Paul Stamler wrote: Does the amount of hum, or its harmonic makeup, change when you move cables a foot or two? What about power cables? If the answer is yes, a new UHF TV station may have sign on in your neighborhood. Peace, Paul Thanks. You know what? It's cable+modem we've recently installed here. Is there any fixes? We don't want to be unplugging the cable everytime we want to record something, especially since we would have to do it at the outlet, or else open cable would still be spewing its stuff everywhere. http://www.epanorama.net/documents/g..._isolator.html Thanks, we'll try this. |
#18
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In article , KingMe wrote:
On 21 Nov 2004 10:30:37 -0500, Scott Dorsey wrote: It's a ground loop, then. The cable modem should be plugged into a different circuit than your audio gear. You are running 10BaseT from the cable modem to the computer, so the fact that the power line ground and the cable ground on the cable modem are nasty, that doesn't matter because the 10BaseT line is balanced and has no reference ground, so it can't carry the ground loop on. My guess is that the third pin on the cable modem has tied your power line ground to the (very nasty) cable system ground and caused an instant loop. Take it somewhere else and run a long 10BaseT line. --scott I could go with this explanation, but the thing is there is no ground pins on the modem. Start tracing, then. Disconnect the 10BaseT line. Does the noise go away? If not, disconnect the power connection and reconnect the 10BaseT line. Does the noise go away? If they are both disconnected but left in place, is the noise there. But you would actually connect the modem+router+stuff "near" everything if you can't isolate them, but since they don't carry ground loops in any case, it doesn't matter. You can put the modem and router anywhere you want. Put them in the garage on a little shelf, near where the phone junction is. Then run a long 10BaseT line out to the computer. Maybe you have a 10BaseT issue. Maybe not. You need to start tracing and find out. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#19
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In article , KingMe wrote:
On 21 Nov 2004 10:30:37 -0500, Scott Dorsey wrote: It's a ground loop, then. The cable modem should be plugged into a different circuit than your audio gear. You are running 10BaseT from the cable modem to the computer, so the fact that the power line ground and the cable ground on the cable modem are nasty, that doesn't matter because the 10BaseT line is balanced and has no reference ground, so it can't carry the ground loop on. My guess is that the third pin on the cable modem has tied your power line ground to the (very nasty) cable system ground and caused an instant loop. Take it somewhere else and run a long 10BaseT line. --scott I could go with this explanation, but the thing is there is no ground pins on the modem. Start tracing, then. Disconnect the 10BaseT line. Does the noise go away? If not, disconnect the power connection and reconnect the 10BaseT line. Does the noise go away? If they are both disconnected but left in place, is the noise there. But you would actually connect the modem+router+stuff "near" everything if you can't isolate them, but since they don't carry ground loops in any case, it doesn't matter. You can put the modem and router anywhere you want. Put them in the garage on a little shelf, near where the phone junction is. Then run a long 10BaseT line out to the computer. Maybe you have a 10BaseT issue. Maybe not. You need to start tracing and find out. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#20
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KingMe wrote:
http://www.epanorama.net/documents/g..._isolator.html Thanks, we'll try this. Here is another: http://www.dplay.com/tutorial/cablehum.html#atten -- ================================================== ====================== Michael Kesti | "And like, one and one don't make | two, one and one make one." | - The Who, Bargain |
#21
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KingMe wrote:
http://www.epanorama.net/documents/g..._isolator.html Thanks, we'll try this. Here is another: http://www.dplay.com/tutorial/cablehum.html#atten -- ================================================== ====================== Michael Kesti | "And like, one and one don't make | two, one and one make one." | - The Who, Bargain |
#22
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KingMe wrote in message ...
I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! I just got an API rack with 10- 212's and 2- 225's. To my dismay, when I connected the new rack with my rack of 550A's I had a horrible buzz and 60 cycle hum issue. I found that someone had lifted the audio ground from the chassis ground on all 12 of the new API's. My advice would be to check the grounds on all your balanced gear with a meter. Put on probe on a good chassis ground (a unpainted screw or something) and the other on pin 1 of the XLR connectors. The meter should show continuity. Your problem sounds a little different than mine. If you don't find any ground issues with the above method, try putting your unbalanced gear in another rack. Two racks may not be a permenent solution, but should at least be a good troubleshooting tool. Bulldog |
#23
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KingMe wrote in message ...
I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! I just got an API rack with 10- 212's and 2- 225's. To my dismay, when I connected the new rack with my rack of 550A's I had a horrible buzz and 60 cycle hum issue. I found that someone had lifted the audio ground from the chassis ground on all 12 of the new API's. My advice would be to check the grounds on all your balanced gear with a meter. Put on probe on a good chassis ground (a unpainted screw or something) and the other on pin 1 of the XLR connectors. The meter should show continuity. Your problem sounds a little different than mine. If you don't find any ground issues with the above method, try putting your unbalanced gear in another rack. Two racks may not be a permenent solution, but should at least be a good troubleshooting tool. Bulldog |
#24
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#26
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Scott Dorsey wrote: In article , KingMe wrote: I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! You have a ground loop. Read the section in the FAQ on ground loops. Does anyone regularly post the location of the FAQ ? Graham |
#27
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Scott Dorsey wrote: In article , KingMe wrote: I don't know when this problem started, but I'm now having 60Hz hums from all my unbalanced equipments. Disconnecting some equipment (electrically isolating them) helps, but that's not going to a solution in the long run. They're all connected to the same plug by surge protector. It does not seem to be affecting balanced equipments for some reason. Does someone have any suggestions? Thanks a lot! You have a ground loop. Read the section in the FAQ on ground loops. Does anyone regularly post the location of the FAQ ? Graham |
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