Power Cords.

[Mr Peabody]

I checked Transparent's website http://www.transparentcable.com/prod...tID=5&modCAT=1 just curious if they show what's inside their cords. They don't show or tell much. The cords I have are probably the entry level, no networks. The MIT, Z cord I have has networks. I use it on my Linn amp, it made a nice improvement.

[squidboyw]

Anyway, it is not so much dirty power that some conditioners work to clean, it is the consistency of the power. The technical term is Power Factor. Furman unit address this.

I'm not an EE but I thought unless using something like a Carver any instantaneous demands were taken care of by the power supply and capacitor banks.

Power factor is not the same as amps and volts.

POWER FACTOR

In AC systems, voltage and current go from positive to zero to negative generally 60 times a second (60 cycles or 60 Hz). If voltage and current are "high" or "low" at the same time, then they are said to be "in phase." A common term to describe the time relationship between voltage and current is called "power factor." When voltage and current are "in phase," the power factor is generally 1 (surprising, this is not always the case ). When the current peak follows the voltage peak, this is called " lagging power factor," when current leads voltage, this is called "leading power factor." When voltage and current are exactly opposite ( when voltage is at a peak and current is zero,or vice versa), the power factor is 0.

"REAL" POWER

Utilities charge us for "real power" i.e. how much work must actually be done by a generator (no matter how it is driven, by a steam turbine, internal combustion engine, dam, wind, etc). To find "real power," you multiply volts time amps times power factor. The power factor is determined by the load, that is, the device using the power. A light bulb produces light by simply heating up a thin metal filament and is called a resistive load (other examples are heaters, toasters, etc). Resistive loads have a power factor of 1, and are the only loads where you can find real power by simply multiplying voltage times current.

A common induction motor, such as those found in washers, freezers, refrigerators and air conditioners, work by storing some of the electricity it uses in a magnetic field. This storage causes the voltage and current to be high at different times, and the resulting real power usage can be a small fraction of voltage times current; this fraction increases as the motor is loaded. For example, an air compressor at start up with an empty tank may consume only 1000 watts, but would over 2000 watts when near shut off pressure. If you measured the current going to the compressor motor as it is loading, it only goes up a little bit, not by a factor of 2! The reason is that the power factor of the motor is changing as the motor is loaded.

Would a better supply have less of an affect from a Furman? No just the opposite!

Think of the power line as a hose when the line becomes inductive think of some one gripping a hose restricting flow now think someone applying more pressure to restore that flow, This is what the Furman does!

Now take the end of the hose this is the power supply of your amp if it is a straw end you can't expect much out of it! But if it is the size of a fire hose and if the pressure is there your going to have flow with volume.

Simply put in an amplifiers perspective! Energy Transfer is the name of the game!

[mlsstl]

Interesting explanation, but the circuits of all of our electronic gear actually run on DC. The only exceptions might be turntable or tape deck motors and even many of those are also DC.

As an electronics hobbyist of some 40+ years, I've got a basement full of test equipment that I still get out and use from time to time. You'd think that you'd see any problems with the supply of available current from the wall reflected in the DC rails of the device in question, but that is not something I've bumped into except under very unusual circumstances.

I suspect the extra suppression of EMI (both received and radiated) is likely a bigger factor in those cases where people perceive a sonic difference between power cords. Of course, there are some cheap power cables supplied with some gear that are inadequate for the job at hand, but those are pretty rare in my experience once you're past the mid-fi equipment.

[Happy Camper]

I have experimented with a few cables. Hospital grade .3m and 2m, standard commercial grade, VD Power 1 and a conditioner strip & isolation transformer..

As mentioned, the noise floor dropped noticeably when I went to the VD in both the amp and DAC directly out of the receptacle. An added benefit of the amp was a more dynamically lively amp. The DAC also portrayed the notes with more detail and longer decay.

I have been able to get the same performance of my DAC with an isolation transformer and the .3m hospital grade. I have two circuits on my iso tranny and I use one side for just my DAC and the other on my PC.

I have kept the VD 1 on my amp directly from the wall and won't go back to a standard power cord again for my amps. Listening on headphones really focuses on changes in the sound.

This link has some good reading on power line noise. Actually, a good read throughout for a sales pitch.. http://www.lessloss.com/page.html?id=17

[Glen B]

Interesting explanation, but the circuits of all of our electronic gear actually run on DC. The only exceptions might be turntable or tape deck motors and even many of those are also DC.

As an electronics hobbyist of some 40+ years, I've got a basement full of test equipment that I still get out and use from time to time. You'd think that you'd see any problems with the supply of available current from the wall reflected in the DC rails of the device in question, but that is not something I've bumped into except under very unusual circumstances.

I suspect the extra suppression of EMI (both received and radiated) is likely a bigger factor in those cases where people perceive a sonic difference between power cords. Of course, there are some cheap power cables supplied with some gear that are inadequate for the job at hand, but those are pretty rare in my experience once you're past the mid-fi equipment.

Here's some interesting reading. The author is a professor of EE and audio enthusiast:

http://www.polkaudio.com/forums/showthread.php?t=71333

http://www.polkaudio.com/forums/showthread.php?t=71382

http://www.polkaudio.com/forums/showthread.php?t=71545

Posts by Ralph Karsten (Atmasphere), designer and owner of high end manufacturer Atma-Sphere Music Systems, on how power cords can make a difference:

http://forum.audiogon.com/cgi-bin/fr...enflup&36&4#36

[mlsstl]

Thanks for the links. It pretty much confirms what I noted before. The power cord should be appropriate for the job at hand. It needs to be of adequate size for the piece of equipment and also include quality connectors at each end. Plus, some setups may benefit from shielding or other EMI abatement techniques. None of that requires an abnormal level of magic - all of those characteristics are pretty well understood by electrical engineers.

One additional comment - the power cord is not the only place where EMI control strategies can be employed.

There are two reasons that different people may experience different results with power cables. The first reason would be that not everyone's power at their home is necessarily contaminated to the same degree. Second, the power cable is not the only place noise can be eliminated. Designers vary in how much attention they pay to their power supply and that, in combination with the differing quality of power at the wall socket, could easily explain why some people hear a difference with a particular power cord and others don't.

And all of that is before we even get to the psychological subjectivities! ;-)