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Gear / Technical Help => Remote Power => Topic started by: dmbdvds on May 07, 2007, 02:01:42 PM

Title: Power Plug Adapter (Reduce Hum/Hiss)
Post by: dmbdvds on May 07, 2007, 02:01:42 PM
I was looking at a thread a few weeks back and read and had a link to an adapter you plug into a wall outlet then plug your laptop into to prevent too much power coming in and effecting your recording. Can someone point me in the right direction?
Title: Re: Power Plug Adapter (Reduce Hum/Hiss)
Post by: dmbdvds on May 08, 2007, 12:33:19 PM
anyone?
Title: Re: Power Plug Adapter (Reduce Hum/Hiss)
Post by: Church-Audio on May 08, 2007, 12:42:18 PM
I was looking at a thread a few weeks back and read and had a link to an adapter you plug into a wall outlet then plug your laptop into to prevent too much power coming in and effecting your recording. Can someone point me in the right direction?

It's called a power conditioner. And if you have too much power coming in to your laptop chances are there is going to be a lot more effected then just your recording :) I would look at companies like APC if you want a good surge protector.

Chris
Title: Re: Power Plug Adapter (Reduce Hum/Hiss)
Post by: dmbdvds on May 08, 2007, 01:04:17 PM
sounds about right, and I saw a link on here for a single plug and it is driving me crazy searching for hours and can't find it again.  History isn't showing either.
Title: Re: Power Plug Adapter (Reduce Hum/Hiss)
Post by: easy jim on May 08, 2007, 02:00:54 PM
In addition to a power conditioner/surge protector, you'll also want to carry a ground lift adapter in your bag if you're planning to tape using AC.

Some clubs have really crappy and/or old wiring where you plugging in to their electrical may cause a ground loop (60hz hum, usually plus multiple resonances at frequencies in multiples of 60).  A ground lift (3 -> 2 prong adapter in US 110v) will help prevent you adding to the (all too common) problem of dirty power and bad wiring.
Title: Re: Power Plug Adapter (Reduce Hum/Hiss)
Post by: Church-Audio on May 08, 2007, 02:03:32 PM
In addition to a power conditioner/surge protector, you'll also want to carry a ground lift adapter in your bag if you're planning to tape using AC.

Some clubs have really crappy and/or old wiring where you plugging in to their electrical may cause a ground loop (60hz hum, usually plus multiple resonances at frequencies in multiples of 60).  A ground lift (3 -> 2 prong adapter in US 110v) will help prevent you adding to the (all too common) problem of dirty power and bad wiring.

There are people out there still using ground lifts for AC.. Not a good idea.. Use a isolation transformers for your inputs from the house console with a pin 1 lift switch on them and you will never have to lift a AC ground again.

Title: Re: Power Plug Adapter (Reduce Hum/Hiss)
Post by: easy jim on May 08, 2007, 02:44:09 PM
There are people out there still using ground lifts for AC.. Not a good idea.. Use a isolation transformers for your inputs from the house console with a pin 1 lift switch on them and you will never have to lift a AC ground again.

Chris,

By "use a isolation transformers for your inputs from the house console..." you are referring to preventing ground loops from plugging a rig into the console, correct?

Wouldn't you still need to lift the AC ground from the quad or whever you plug in your power conditioner/surge protector if you need AC power for a recorder/computer/external pre-amp, etc.? 

I am still learning all this electrical stuff, so I am eager to see your response.  It has been my experience in a lot of smaller clubs that the problem originated from plugging in to the AC outlet of a quad/power strip that is not adequately wired, and that no issues occured when plugging in to the console while running my recording rig on battery power. 
Title: Re: Power Plug Adapter (Reduce Hum/Hiss)
Post by: Church-Audio on May 08, 2007, 02:54:24 PM
There are people out there still using ground lifts for AC.. Not a good idea.. Use a isolation transformers for your inputs from the house console with a pin 1 lift switch on them and you will never have to lift a AC ground again.

Chris,

By "use a isolation transformers for your inputs from the house console..." you are referring to preventing ground loops from plugging a rig into the console, correct?

Wouldn't you still need to lift the AC ground from the quad or whever you plug in your power conditioner/surge protector if you need AC power for a recorder/computer/external pre-amp, etc.? 

I am still learning all this electrical stuff, so I am eager to see your response.  It has been my experience in a lot of smaller clubs that the problem originated from plugging in to the AC outlet of a quad/power strip that is not adequately wired, and that no issues occured when plugging in to the console while running my recording rig on battery power. 

You always need surge protection.. But as soon as you tie into the House PA. And your running on AC for your recording gear you should use a transformer to isolate the two systems from each other. This allows both systems to be grounded and not effect the other system.. Its important to remember under no circumstances should you ever cut AC ground. Its stupid and dangerous. As a sound engineer I have seen a guy get electrocuted on stage from some dumb ass cutting AC ground.. So I think the cost of a pair of nice transformers and a audio ground lift switch are good insurance policies for your gear. Also for most gear when your running on AC any static discharge will be dissipated thru AC ground if its not there then where does that static go? Some times you have a good clean AC system and you dont need the transformers but sometimes you do..


When your recording on battery power there is no such thing as a ground loop between the Main house PA and you. Since only one end of your gear is tied to ground your ok.. If you ever have issues when your running on battery power its not a ground issue its a wiring issue or its a noisy output on the console issue. Remember that your signal to noise ratio is so much better then a 40 channel mixer with all of its preamps opened up and 30 some odd microphones plugged in to it.. So hiss and noise from a mixer output can be under some circumstances normal..

Chris
Title: Re: Power Plug Adapter (Reduce Hum/Hiss)
Post by: ArchivalAudio on May 08, 2007, 06:24:13 PM
is it also not true that
you can be sure you are also coming out of the same 110v power source as the house PA , mixing console.
I know when I have had a 60  cycle buzz
if I moved my power to the same on as the baord it went away, provided that it could handle the extra draw.