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Power Filtration

"Power is a vital factor when considering audio equipment."

 

To reproduce a believable and accurate audio signal you need a clean and readily available power. The amplifier's job is to take a signal and enlarge it while adding as little noise or colour of it's own as possible, at both low and high volumes. Amplifiers do this by using the input voltage (AC Mains power), converting that power to a DC signal, and then adding this to the input signal to drive your speakers. (Slightly more accurately, the DC voltage is modulated by the input signal, but amplifiers are a separate article.)

 

It stands to reason, then, that the cleaner the input signal, the cleaner the output signal; no one disputes that getting a cleaner, more accurate music signal from the source will influence the quality of sound that comes from the speakers. Similar things happen with the power.

If you've ever turned on your amplifier and heard an ever so slight 'hiss' or rushing sound, or maybe a 'pop' as the refrigerator kicked on, you are hearing the influence of mains power on your system.

 

"...The cleaner the input signal the cleaner the output"

 

The power in your walls not only has to travel a long distance, but it is also compromised by an ever growing assortment of wireless interferences; this can be from powerful radio signals from your local radio broadcaster or your in-home wireless router.

 

Ethernet over power, or 'Powerline' networking, which actively sends high frequency noise into your home's electrical cabling can be another major source of interference. Even some of the new 'Smart Metering' systems utilities use this method across the power grid.

 

Your amplifier normally assumes a 'clean' AC waveform, and when it tries to recreate a musical signal from this power, it can adversely impact the fidelity. From raising the noise floor to 'smearing' or 'muddying' the sound stage, the effects can be quite subtle or very pronounced.


It's worth noting here that some have attempted to attribute mains 'hum', a 50 Hz hum, as a product of dirty power. This is absolutely not the case, but is in fact due to an issue with your grounding.


Well then, how does one 'clean' power? Filters, of course. Filters can be constructed using Electrolytic capacitors, and this is a very common and inexpensive way to accomplish this. They will filter out a large amount of the noise above a certain frequency, though the characteristics of the filtration can vary with temperature and age. It's not uncommon for these to actually ADD noise into the system once they go bad.

 

For a more reliable and ultra effective way to remove high frequency noise, a 1:1 transformer can be used. Effectively two large coils of copper, voltage is run through one, and a voltage is induced in the other. There is no electrical connection, but 240v / 50hz goes in one coil, 240v / 50hz out the other end.

 

The benefit comes in that this induction process is not very good at sending high frequency oscillations - noise - so the transformer acts as a very reliable low pass filter, sending only the 240v / 50hz mains power, without any of the noise.  

 

For a more reliable and ultra effective way to remove high frequency noise, a 1:1 transformer can be used. Effectively two large coils of copper, voltage is run through one, and a voltage is induced in the other. There is no electrical connection, but 240v / 50hz goes in one coil, 240v / 50hz out the other end. The benefit comes in that this induction process is not very good at sending high frequency oscillations - noise - so the transformer acts as a very reliable low pass filter, sending only the 240v / 50hz mains power, without any of the noise.


We recently got to play with the Furman's Elite-16 PF E i , a new brand for Sound Group Holdings. It's understated box pays tribute to Furman's professional sound background. They have, of course, been supplying live and studio music with clean power for 40 years. Just look at their band roster! http://www.furmanpower.com/page.php?div=01&%3Bid=ARTISTS

We installed the Furman into our house system, comprising of Yamaha's flagship A-S3000 amplifier, the matched CD-S3000 CD Player and their NP-S2000 network streamer, accompanied by Paradigm's 30th anniversary Tributes.

Furman incorporates three separate banks of filtration, one for amplifiers and high current demanding circuits, a second for audio source equipment such as CD players, DACs and turntables and a third for video (projector, panel, bluray)
 

"...Furman incorporates three separate banks of filtration"‚Äč
 

Instantly the A-S3000 seems to have a lot more grunt, and grunt is something I would not imply it was lacking. It's bass control was fantastic, as was it's separation.

 

Because it lowers the noise floor considerably, everything stands out a lot more. Details that I haven't heard before, underlying bass notes and transients reveal themselves.


Everything has so much more space and the natural reverb of the recordings transport me into the recording studio. Just when you think your system can't get any better, it does.

The Furman now is a permanent resident in our house system, so come in and have a listen!

 

-William-

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