Technology
The Ultimate Outlet (UO) is a smallish metal box with an IEC input connector at one end and a duplex AC socket at the other. Inside the box is a type of transformer called a balun. Prior to my acquaintance with the UO, the only balun that I was familiar with was the type used to match a 75 ohm coaxial antenna cable to the 300 ohm antenna terminals of a TV set. In fact, balun transformers are used widely in RF/microwave transmission applications, but, according to PS Audio's Paul McGowan, the UO represents the first use of a balun in an AC power context.
A balun is a fairly simple device, consisting of a donut of iron with wire wrapped around each half of the donut. The balun used in the UO has the wire connected directly from input to output, so that it's not like an isolation transformer. The claimed advantages of the balun-based over the series/parallel filter or isolation-transformer-based approaches to power-line conditioning are: a) cancellation of noise at a much wider range of frequencies, b) reduction of differential as well as common-mode noise, and c) no limitation of power.
