Waveform 15 AC Power Part 2
Posted: Fri Dec 31, 2004 3:03 pm
Another type of power product used to improve system performance is an isolation transformer and the different variations of this concept that isolates RF radiation on the AC line from the equipment in your system. The key benefit of these over their AC filter competitors is the fact they literally electrically isolate the input AC power from the output AC power you connect your equipment to. Just this fact by itself can provide an immediate benefit if your system is suffering from minor ground loops that are not easily apparent to your eyes or ears. Due to the low frequency nature of this design isolation from RF radiation is part and parcel of the application. If you are looking for an improvement in performance this type of AC power product is more likely to provide a benefit.
When using an audio distortion analyzer, RTA or scope with these products it is impossible for me to find any improvement when comparing the AC going into the product with the conditioned AC being provided to the outlets. I freely acknowledge that a distortion analyzer that deals with RF frequencies and having an AC source with RF radiation clearly on it may do a better job of proving a benefit yet I have already acknowledged that the AC input filter on these products, whether by design or actual circuit and components, can provide a benefit under the right conditions.
In my investigation of AC power products I also built a few of these using commercially available parts or pre-constructed filters that are readily available including the simple test of plugging in an old VCR that uses an AC power transformer which I found to have a similar effect. Numerous tests were performed listening to a state of the art stereo system to determine performance benefits based upon the change in sonic signature. With any of these products or my own designs and the VCR I found that indeed they affected the response of the system. In general all of them had one consistent effect on the response which was better bass. What was problematic is that beyond that each had a slightly different effect on the sonic signature affecting imaging in depth and width and subtle variations in frequency response as in the mid range for vocals or upper registers for brightness such as cymbals and air. Due to this I can only recommend them for the purpose of affecting the synergy of an audio system. Synergy is the term we use when consistent performance of a product cannot be expected due to the other elements of the system and therefore the individual components are determined by the sonic signature you are trying to achieve rather than an accurate and consistent result that one can depend upon and apply anywhere in the world.
But this is an HDTV column about video isn
When using an audio distortion analyzer, RTA or scope with these products it is impossible for me to find any improvement when comparing the AC going into the product with the conditioned AC being provided to the outlets. I freely acknowledge that a distortion analyzer that deals with RF frequencies and having an AC source with RF radiation clearly on it may do a better job of proving a benefit yet I have already acknowledged that the AC input filter on these products, whether by design or actual circuit and components, can provide a benefit under the right conditions.
In my investigation of AC power products I also built a few of these using commercially available parts or pre-constructed filters that are readily available including the simple test of plugging in an old VCR that uses an AC power transformer which I found to have a similar effect. Numerous tests were performed listening to a state of the art stereo system to determine performance benefits based upon the change in sonic signature. With any of these products or my own designs and the VCR I found that indeed they affected the response of the system. In general all of them had one consistent effect on the response which was better bass. What was problematic is that beyond that each had a slightly different effect on the sonic signature affecting imaging in depth and width and subtle variations in frequency response as in the mid range for vocals or upper registers for brightness such as cymbals and air. Due to this I can only recommend them for the purpose of affecting the synergy of an audio system. Synergy is the term we use when consistent performance of a product cannot be expected due to the other elements of the system and therefore the individual components are determined by the sonic signature you are trying to achieve rather than an accurate and consistent result that one can depend upon and apply anywhere in the world.
But this is an HDTV column about video isn