Just started to get an earth loop using my laptop as source connected
to amp.
just starte
get 'cricket' type sounds when the laptop is connected to power lead.
problem goes totally when i half remove the power lead,
gets unlistenable when the power lead is removed and laptop running on
battery.

only just started happening, any ideas?

philcud wrote:
Just started to get an earth loop using my laptop as source connected
to amp.
just starte
get 'cricket' type sounds when the laptop is connected to power lead.
problem goes totally when i half remove the power lead,
gets unlistenable when the power lead is removed and laptop running on
battery.

only just started happening, any ideas?

If it gets to a point where you can hear it running on just battery
power, it's not a ground loop, it's a defect inside the laptop.

On the other hand, if it goes away totally when you run on battery, then
you may have a power brick problem. Try another power brick if you've
got one available.

It's *possible* your battery is defective, which is causing the power
supply on the motherboard in the laptop to become unstable, causing the
sound to chirp.

--
Tciao for Now!

John.

In article
,
philcud wrote:
Just started to get an earth loop using my laptop as source connected
to amp.
just starte
get 'cricket' type sounds when the laptop is connected to power lead.
problem goes totally when i half remove the power lead,
gets unlistenable when the power lead is removed and laptop running on
battery.

only just started happening, any ideas?

Earth loops occur when there are two ground paths at different potentials.
Usually the screen of the interconnecting cable and mains earths via the
mains plug. And takes the form of hum. If you are running the laptop on
batteries with the power supply disconnected totally it can't be an earth
loop.

--
*If at first you don't succeed, avoid skydiving.*

Dave Plowman London SW
To e-mail, change noise into sound.

philcud wrote:

Just started to get an earth loop using my laptop as source connected
to amp.

No, you've probably got a leakage current from the mains PSU.

Have you tried disconnecting the mains PSU ENTIRELY ? I.e. running on
battery power only with no attachment whatever to the PSU ?

Graham

John Williamson wrote:

philcud wrote:
Just started to get an earth loop using my laptop as source connected
to amp.
just starte
get 'cricket' type sounds when the laptop is connected to power lead.
problem goes totally when i half remove the power lead,
gets unlistenable when the power lead is removed and laptop running on
battery.

only just started happening, any ideas?

If it gets to a point where you can hear it running on just battery
power, it's not a ground loop, it's a defect inside the laptop.

Agreed.


On the other hand, if it goes away totally when you run on battery, then
you may have a power brick problem. Try another power brick if you've
got one available.

It's inherent in almost every power brick. Laptops weren't designed as
quality audio sources, whatever the marketing says.


It's *possible* your battery is defective, which is causing the power
supply on the motherboard in the laptop to become unstable, causing the
sound to chirp.

Pretty long shot but you never know. I'd lay my money more on the internal
voltage regulators if it's in that area.

Graham

"Dave Plowman (News)" wrote:

In article
,
philcud wrote:
Just started to get an earth loop using my laptop as source connected
to amp.
just starte
get 'cricket' type sounds when the laptop is connected to power lead.
problem goes totally when i half remove the power lead,
gets unlistenable when the power lead is removed and laptop running on
battery.

only just started happening, any ideas?

Earth loops occur when there are two ground paths at different potentials.
Usually the screen of the interconnecting cable and mains earths via the
mains plug. And takes the form of hum. If you are running the laptop on
batteries with the power supply disconnected totally it can't be an earth
loop.

Very true.

Graham

Dave Plowman (News) wrote:
In article
,
philcud wrote:
Just started to get an earth loop using my laptop as source connected
to amp.
just starte
get 'cricket' type sounds when the laptop is connected to power lead.
problem goes totally when i half remove the power lead,
gets unlistenable when the power lead is removed and laptop running on
battery.

only just started happening, any ideas?

Earth loops occur when there are two ground paths at different potentials.
Usually the screen of the interconnecting cable and mains earths via the
mains plug. And takes the form of hum. If you are running the laptop on
batteries with the power supply disconnected totally it can't be an earth
loop.

Could the problem be that there is no earth in the system
rather than too many?

--
Eiron.

Eiron wrote:
Dave Plowman (News) wrote:
In article
,
philcud wrote:
Just started to get an earth loop using my laptop as source connected
to amp.
just starte
get 'cricket' type sounds when the laptop is connected to power lead.
problem goes totally when i half remove the power lead,
gets unlistenable when the power lead is removed and laptop running on
battery.

only just started happening, any ideas?

Earth loops occur when there are two ground paths at different
potentials.
Usually the screen of the interconnecting cable and mains earths via the
mains plug. And takes the form of hum. If you are running the laptop on
batteries with the power supply disconnected totally it can't be an earth
loop.

Could the problem be that there is no earth in the system
rather than too many?


Never a problem. You don't get hum problems with battery-powered gear.

d

Don Pearce wrote:
Eiron wrote:
Dave Plowman (News) wrote:
In article
,
philcud wrote:
Just started to get an earth loop using my laptop as source connected
to amp.
just starte
get 'cricket' type sounds when the laptop is connected to power lead.
problem goes totally when i half remove the power lead,
gets unlistenable when the power lead is removed and laptop running on
battery.

only just started happening, any ideas?

Earth loops occur when there are two ground paths at different
potentials.
Usually the screen of the interconnecting cable and mains earths via the
mains plug. And takes the form of hum. If you are running the laptop on
batteries with the power supply disconnected totally it can't be an
earth
loop.

Could the problem be that there is no earth in the system
rather than too many?


Never a problem. You don't get hum problems with battery-powered gear.

And what's the amplifier powered by?

--
Eiron.

Eiron wrote:
Don Pearce wrote:
Eiron wrote:
Dave Plowman (News) wrote:
In article
,
philcud wrote:
Just started to get an earth loop using my laptop as source connected
to amp.
just starte
get 'cricket' type sounds when the laptop is connected to power lead.
problem goes totally when i half remove the power lead,
gets unlistenable when the power lead is removed and laptop running on
battery.

only just started happening, any ideas?

Earth loops occur when there are two ground paths at different
potentials.
Usually the screen of the interconnecting cable and mains earths via
the
mains plug. And takes the form of hum. If you are running the laptop on
batteries with the power supply disconnected totally it can't be an
earth
loop.

Could the problem be that there is no earth in the system
rather than too many?


Never a problem. You don't get hum problems with battery-powered gear.

And what's the amplifier powered by?


Doesn't matter. You only connect to earth for safety.

d