[PeterCapo]

Greetings:

Happened upon this device and wondered what you folks think of it: http://www.ebtechaudio.com/humxdes.html

Seems kind of small to be an isolation transformer.  I will probably contact the manufacturer to inquire further but wanted to know your impression.

No affiliation with the company or sellers of this product.

Thank you.
Peter

[Wayner]

Peter,

It's seems like an odd device to me. Since electricity travels at approximately the speed of light, what keeps the noise that is eaten up the this device not the same noise entering my other electronics?

Wayner

[PeterCapo]

Apparently, some pieces of equipment in a system seem to be more inclined than others to have problems with hum, even over the same power line.  I've experienced this in my own system.

One of these things can handle 6A of current, so I guess you could plug a power strip into it and use it for more than one piece of equipment as long as you don’t exceed the current rating.

Beyond this, I can’t say that I know the theory behind how it works and why hum is more of a problem for some pieces of equipment than others.

For what it’s worth, I did a little research and I’ve seen some positive commentaries on this device.

[turkey]

The Hum X could simply lift the ground. That would break the loop, although it's not always safe to not have a ground.

Some of their other products appear to be small signal-level isolation transformers in a fancy box. I'd probably just get some Jensen transformers instead and build something on my own.

Using isolation transformers in the signal path is the better approach BTW.

[Occam]

It 'stands off' the mains ground by a diode drop, via the use of 2 antiphase diodes in parallel separating the safety ground from its connection. If the components safety ground connection has a voltage of > |1.3v| a connection is made. Others can comment on its safety.....

[Wayner]

Oops, my fault. I didn't see that this thing had an outlet on the top. I thought it was like the pS noise harvestor, which I don't understand either.

Wayner

[markC]

It 'stands off' the mains ground by a diode drop, via the use of 2 antiphase diodes in parallel separating the safety ground from its connection. If the components safety ground connection has a voltage of > |1.3v| a connection is made. Others can comment on its safety.....

So, if I understand correctly, unless there is more than 1.3v on the safety ground it is "disconnected" via the open diodes. Electrical safety would then rely on the diodes. I can't see a CSL approval for that.
That being said, I feel that it would be much safer than a cheater plug.

[Tom Alverson]

It 'stands off' the mains ground by a diode drop, via the use of 2 antiphase diodes in parallel separating the safety ground from its connection. If the components safety ground connection has a voltage of > |1.3v| a connection is made. Others can comment on its safety.....

I was guessing that  it was a big 10 ohm resistor in the ground lead, but the diodes sound a little bit better.  My second guess was an inductor  in the ground lead that had at least 10 ohms or more reactance at 60hz.  Maybe and inductor or resistor in parallel with the  diodes would be better.  Seems a little overpriced to me.

[turkey]

Oops, my fault. I didn't see that this thing had an outlet on the top. I thought it was like the pS noise harvestor, which I don't understand either.

It's pretty simple.

Most power line noise reduction is done by dumping the noise to ground, or blocking it from entering the power supply of your equipment.

This gadget uses the noise on the power line to power a light. So, for example, you might have all frequencies higher than 60 Hz powering a light bulb in the hopes that the light will dissipate the noise.

Personally, I think it's snake oil. But I haven't really thought that any of their products were worthwhile since Stan Warren left. They're more or less BS Audio at this point...

[avahifi]

A way to address ground loop?

Start the letter with:

Dear Mr. G. Loop;



FVA

[BrianM]

"Hey you."

[turkey]

"Hey you."

Loopy Darling,

[dB Cooper]

A way to address ground loop?

Start the letter with:

Dear Mr. G. Loop;



FVA

 

[Brett Buck]

   Hold opposite aileron when turning into the wind?

     Brett

[avahifi]

Be especially careful with a P47.

Frank