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!

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)...

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)...

"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

"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

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.

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.

"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

"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

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."

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."

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."

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."

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.

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.

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.

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.

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."

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."

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

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

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

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

(bulldog) wrote in message om...
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


It helps if you know something about cable shielding and such before
giving advice.

Isolating things to differant racks will make things worse. Don't
listen to Bulldog he's a Troll that doesn't know what he's talking
about.

In your system everything should be Star grounded, all grounds come
to the same point.

You want to be playing with the shields on your unbalanced gear to
find out what to lift in order to eliminate the loop.

What are the actual units you are running to what that is making the
noise?

Do you have a patchbay? How was the shield lifting done in your cable
setup?

(bulldog) wrote in message om...
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


It helps if you know something about cable shielding and such before
giving advice.

Isolating things to differant racks will make things worse. Don't
listen to Bulldog he's a Troll that doesn't know what he's talking
about.

In your system everything should be Star grounded, all grounds come
to the same point.

You want to be playing with the shields on your unbalanced gear to
find out what to lift in order to eliminate the loop.

What are the actual units you are running to what that is making the
noise?

Do you have a patchbay? How was the shield lifting done in your cable
setup?

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

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