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What we suffer as a result is a polluted grid where PE conducts HF noise. Worse, it radiates noise into the air where it gets picked up by adjacent equipment. This means that defeating the ground pin by using a cheater plug (US) or plugging a 3-lead Schuko into a wall outlet without ground wire isn't helpful. The unshielded (!) PE wire acts as antenna regardless. With EMC three factors are at work - emissions, susceptibility and the path between them. Emissions (EMI) come from equipment. Their susceptible receiver can either be reached through a radiation path like an electromagnetic field or via a conducted/connected path were electrical currents run. Examples of radiation emission sources are clocks, data lines and switching power supplies. Susceptible receivers are poorly laid-out data lines and clock lines - in other words faulty PCB design. For conducted EMI emissions, power supplies and more specifically SMPS are the culprits. How cynical then is the shielding to prevent the radiation emissions mentioned above. Susceptible to these very emissions are—tada!—power cords and their attached power rails.

Joe Cohen’s Linebacker wraps all leads—hot, neutral and PE—into the same crystalline substance to effectively absorb noise from all three lines. The effectiveness thereof was easily assessed by listening and corroborating to a certain extent with the Noise Analyser. In our first setup we had used the Linebacker as a pre filter ahead of a passive Furutech power distribution block. This of course meant that the latter saw multiple power cords run to the associated equipment like a star or kraken. All these cords are susceptible to some form of radiated EMI, be it injected into the cable or in the case of a shielded cable, into the connectors. To isolate the Linebacker as a dedicated power line filter, we moved to our second system. Here we have a PS Audio PWT/PWD combination, Audio Note Meishu integrated amp and Avantgarde Acoustic Duo Omega horns. First we did some listening without any filtering, just Crystal Cable and ASI power cables in combination with a Furutech TP60E distribution block. Then we did the same with the Pranawire Linebacker feeding the distribution block and finally dedicating the Linebacker to just the Meishu.

The sonic difference between plain Jane setup and Linebacker as Big Brother was a no-brainer. We had already seen the measurements whereby the Linebacker attenuated the noise by roughly 75%. Aurally that translated to greater quiet, far more intelligible detail, more natural decays and faster transients. Hooking up the Meishu to the Linebacker whilst all other contenders drank from the TP60E and then the wall was a mixed bag. It is always tricky to power cycle a DAC. These things have a mind of their own and punish their owners with awkward behavior when being disconnected from the grid for too long. The PS Audio PWD handles around 30 seconds before it realizes that power has gone and a sort of reburn-in is required. Our cable swap time was short enough to stay clear of such issues. The sound however lacked the snap and sense of unity which makes a system really work in unison. Especially the finish of a tone, the minute roll-off creating the decay into nothingness was lacking to produce a disinterested inarticulate expression.

Switching everything back to the Linebacker-for-all setup returned that articulation and captivating characteristic we had appreciated before. This meant that at least for us there was no justification for more than one Linebacker. Have it precede your current power distribution solution to be the direct interface with the wall and presto – cleaner power for all. Joe Cohen has authored a clever way to combat power line noise including the grimy stragglers riding on the PE wire. Using natural resources like crystals to convert electrical current into heat which would otherwise interfere with the musical representation isn’t the easiest solution. To learn how much of what substance is required without creating an anaconda monstrosity must have been its very own adventure. In our tests through various setups with their inherent noise-generating capabilities plus external noise sources, each time the Linebacker was included, calmness and quiet entered the scene and unrest and indecision left the building. Now where is Elvis when you need him?

Condition of component received: Excellent.
Quality of owner's manual: n/a
Website comments: At the time of publication no information on the Linebacker except a brief announcement.
Pricing: $1.950 is a real world figure.
Human interactions: Friendly and courteous but mum on the secret ingredients.
Remark: The Linebacker needs an additional power cord which not only adds to the total cost but will invariably add some kind of character to the outcome.


PranaWire comments: "Thank you for all your effort and thorough thoughtful review. I see no reason why I should be unhappy with your conclusion. I will say that audio is necessarily representative of the fable of the blind men and the elephant. It is impossible to see and know all of the ramifications of all the possible interactions amongst all the possible varieties of gear. We've had excellent results using the Linebacker directly into individual pieces of gear and further improvements using more than one in a system. The case of going directly into the Meishu vs. feeding the entire system simply highlights the complexity of interactions in any given system. Though your system benefited being fed globally by the Linebacker, the result was less than stellar when fed directly into the Meishu.


"I am not at all surprised. Though we have not experienced the exact inverse (where feeding the entire system was not pleasing but feeding an individual component was), we have experienced a greater benefit going directly into one component and a lesser benefit feeding one (particular) entire system. What shall we attribute these differences to? Was the individual component in question more or less in need of further isolation? Were the other components that did not receive the Linebacker more or less in need of further isolation? Was the device feeding the entire system more or less in need of further isolation? Was any particular component in the chain "tuned" with a certain amount of noise as a necessary component? No one can predict these things. Experimentation is in order.


"Ideally the Linebacker should be subtractive of noise and additive of little or nothing else. It may be useful for people trying to understand its effects to look at it in this light. Thank you for your characterization of the pricing of the Linebacker as 'real world'. One of the most difficult tasks in putting out a new product is getting the price right. In the case of the Linebacker we purposely kept the price lower than our calculations would normally dictate in the hopes that more people will be able to benefit from its use."
PranaWire website