Modem power plug orientation changes audio sound.

[GeneZ]

How many of us simply plugged in our modems to an outlet and moved on? The power plug orientation to the outlet will effect what you hear.

 

If your plug allows you to, try turning the power plug in the opposite direction and listen for a while. One orientation will sound better. Same principle applies to all audio components that have two pronged plugs that can be plugged in more than one way.

 

Its something that was known back in the day before the three prong AC plugs became popular. All the modems I have had only came with the two prong type AC plugs. That includes wireless routers as well for the sound.

 

Determining Proper A/C Polarity

[maelob]

Not just for Modems but that has been predicated for stereo equipment- something about ac polarity. Jim Smith in Get Better Sound discusses the issue for stereo equipment. There is a way to test the socket but i am not an electrician lol.

[wgscott]

[rodrigaj]

I would be interested if someone could suggest a way of determining the proper polarity when replacing a power cord in old audio equipment (prior to the IEC connections), when power cords were soldered in.

[GeneZ]

[ATTACH=CONFIG]23327[/ATTACH]

 

 

That is used to see if the socket is wired correctly. To see if the equipment is properly oriented in that socket is shown in the link I provided in the first post.

 

I actually had one piece of equipment that came with an IEC socket and it was not wired for correct polarity. I had to make a dummy plug by taking a cheap cord and cutting off the ground prong so I could flip the cord in the socket.

 

http://www.amazon.com/Power-Gear-50542-3-Wire-Receptacle/dp/B002LZTKIA

 

Click on picture to enlarge.

[wgscott]

I have his videos. I liked most of it, but what he was demonstrating there really scared the shit out of me.

[GeneZ]

I would be interested if someone could suggest a way of determining the proper polarity when replacing a power cord in old audio equipment (prior to the IEC connections), when power cords were soldered in.

 

Look online for a used Namiki DF-100. Makes it real easy. I saw some on Ebay..

Click on photo to enlarge.

 

[Speedskater]

OK, so we have three different situations here:

 

1] In most hi-fi components, the AC power supply is asymmetrical with respect to the chassis. That is, there is more leakage current from one end of the transformer to the chassis, than from the other end. Good circuit designers know this and spec which end of the transformer is to be connected to the Neutral.

As a side note, this is why balanced AC power seldom works as well as advertised.

 

2] By rule a component's fuse and switch need to be connected to the AC Hot wire.

 

3] Errors in the building AC wiring. This is way too common, but those little 3 LED testers only catch some of the problems. They miss Bootleg Ground errors.

 

This from a pro audio guy:

[h=1]Failures in Outlet Testing Exposed[/h] Mike Sokol | Electrical Construction and Maintenance

Why standard outlet testing methods fail to reveal reverse polarity bootleg ground mis-wiring situations

Failures in Outlet Testing Exposed

[wgscott]

that was eye-opening. I think I will get one of those testers.

[GeneZ]

that was eye-opening. I think I will get one of those testers.

 

The Nakimi makes it a breeze..

 

Shimano RS685 hydraulic disc, Di2 Ultegra, Chris King wheels and hubs, Enve CX fork, custom steel frame, 35 x 700 Clement Xplor USH. Brooks B17 with copper rivets.

 

For better sound... vintage baseball cards, clipped on between the spokes with a wooden clothes pin sound much better than the new cards do. I think it had to do with the type of bubble gum they used pack them with back then.

[SerJacopo]

After disconnecting all of your cables take a voltmeter and measure the AC voltage between the ground on your piece of equipment and the outlet you're plugging into. There will be a substantial voltage difference reading between one reading and another. The lower one is the correct plug orientation. This applies to all components in your system.

[GeneZ]

After disconnecting all of your cables take a voltmeter and measure the AC voltage between the ground on your piece of equipment and the outlet you're plugging into. There will be a substantial voltage difference reading between one reading and another. The lower one is the correct plug orientation. This applies to all components in your system.

 

Yes..thanks. Its important when measuring that the component is not connected to any other components with interconnects. That's important to do. If there is no obvious ground to connect to, I sometimes will loosen a screw attached to the chassis and attach the VOM clip to that exposed screw to get a reading from the chassis.

[Oystein]

After disconnecting all of your cables take a voltmeter and measure the AC voltage between the ground on your piece of equipment and the outlet you're plugging into.

 

Maybe not claer to all but the ground of your equipment is the outer part of your RCA input (or pre-amp out which should be the same) and the groud of your power outlet is the ground/earth pin.

 

I will take it even a little further.

I do not go for the lowest individual values but for the lowest difference between my equipment.

 

For example my NAD pre is 110V both ways (220V mains) and I think this is because there is a filter at the line input with some capacitors and the middle between the 2 capacitos is connected to groud ... You see this at most RFI filters too.

 

My power amp has diffeent values between the 2 powerplug positions (EU Schuko) so I use it with the value closest to the 110 Volt of the pre.

The lower the voltage difference the lower the leakage currents which really creates the little signal erors as soon as connected via the interlinks.

 

Thing of course gets more complicated when I connect the line out from my TV to my pre.

The TV is also connecte to the antenna cable which has its own (grounded) potential.

 

I guess I should start with the TV with only antenna cable and of course power plugged in ... measure ... compare to pre .. find lowest difference ... conect line out from TV to pre ... measure pre again and compare to power amp ... only change powerplug from power amp for lowest value ... connect interlinks ...

 

And what happens to other sources which are also connected to the pre amp ... still overseeing the complications ?? ... Hahaha

[GeneZ]

I would be interested if someone could suggest a way of determining the proper polarity when replacing a power cord in old audio equipment (prior to the IEC connections), when power cords were soldered in.

 

Why? If its a plain two-pronged plug? Makes no difference. For, you will need to test for correct polarity when you plug in the component and turn the plug in the right direction that gives the best reading. If its a polarity two prong plug? You will need to test with the original plug and mark the correct direction needed. Note which side is to be the hot, and which is to be the return. Look for diagram pictures online if need be. I believe the narrow slot is the hot, and the wider slot is the return.

[GeneZ]

Maybe not claer to all but the ground of your equipment is the outer part of your RCA input (or pre-amp out which should be the same) and the groud of your power outlet is the ground/earth pin.

 

Your actually measuring for voltage running through the chassis. Amps and preamps sometimes have separate ground screws because the grounds can act differently. The best way I found is to find some way to connect directly to the chassis itself. I try to loosen a screw part way out and clip to that. Or, if need be, open the case and connect to something inside that runs directly to the chassis.

[Oystein]

For the best sound quality you want to have the lowest possible leakeage current running over the ground of your interlinks.

Therefore meausure the voltage on the RCA.

[GeneZ]

For the best sound quality you want to have the lowest possible leakeage current running over the ground of your interlinks.

Therefore meausure the voltage on the RCA.

 

One should not be different than the other as far as which one is correct? Clipping to RCA outputs tended to snap off easily, and alligator clips could potentially damage the finish plate on them? And, I was not always able to get an accurate reading that way. Measuring from the chassis was always apparent. Its why some tube amps have a dedicated ground to use for setting the bias. Using the RCA would not give a reliable reading.

[Bob Stern]

If unplugging the RF cable input to ur cable modem makes a big improvement, try a DC blocker between RF cable & modem

[GeneZ]

If unplugging the RF cable input to ur cable modem makes a big improvement, try a DC blocker between RF cable & modem

 

Could you please rephrase that? How could disconnecting the modem make it better? And, I am using DSL, not cable.

 

I was talking about the power cord, not the signal transfer cabling.

[Bob Stern]

I am using DSL, not cable.

I was thinking of cable modems. In some cable systems the RF cable has a DC or 60 Hz voltage that interferes with other equipment. Sensitivity to the polarity of the AC power to the cable modem can be a symptom of this.

[esldude]

The Nakimi makes it a breeze..

 

 

 

For better sound... vintage baseball cards, clipped on between the spokes with a wooden clothes pin sound much better than the new cards do. I think it had to do with the type of bubble gum they used pack them with back then.

 

I prefer using balloons in place of the cards. Much nicer sound, and can be so pretty too. Surely you guys have used balloons before haven't you?