Enlil Mains Isolation Transformer
The importance of mains supply purity is known already long time and treated in various ways by manufacturers. The cheapest solution is the use of passive filters but their negative effect on sound and modest effectivness misses our criteria. On the other hand Power Plant AC Regenerator (AC Line Conditioner) might be the purest supplier of mains energy however its cost is very high and power limited, without any headroom. The third option is isolation transformer, the solution we find most attractive for a series of reasons.
Power in our homes, regardless of what country we live in, is unbalanced. This means there is a hot and a neutral power connection. In Europe, the hot has 230V AC on it and the neutral has zero AC, (120V in North America). A balanced power system has two hot connections and no neutral. Each of the hot terminals has 115 volts AC out of phase with the other and between them there is the same 230 volt AC. The two hot terminals in a balanced system add together. Balanced power is superior for several reasons, chief amongst them is improved noise rejection by the power supplies of the equipment using the balanced power. Noise on the line can be improved by as much as 10dB using a balanced configuration.
- low loss isolation transformer with very low magnetic flux and current density
OUTPUT LOAD CAPACITY: 500VA continuous, 24 hours/day operation
AC Power Conditioners Explained
An AC power conditioner plugs into the wall outlet and provides multiple AC outlets for plugging in your audio equipment. But before we talk about what a power conditioner does, let's look at the AC power line and its relationship to an audio system.
The AC power from the wall outlet is a 50Hz, 230V RMS sinewave that powers the audio system. All your components are connected via the power line. In fact, your audio components are connected to every other electrical device in your house, and to every home and factory also using the power grid. Power equipment on the AC line generates noise that travels back into the line where it enters your audio components. The FCC regulates the amount of noise that can be put back into the power line by appliances and industrial products. This noise is called electromagnetic interference, or EMI. Light dimmers, refrigerators and other household appliances put high-frequency junk in the AC line. Vacuum cleaners and electrical power tools are a major source of power-line noise because the fibers in the motors' brushes are continually making and breaking contact. The line is also polluted by AM radio stations; power lines act as antennae, superimposing the AM signal over the 50Hz line.
Another source of EMI is your audio system. CD players, digital processors, CD transports and any component using a microprocessor put noise on the power line through their line cords. This noise then gets into preamps and source components to degrade their musical performance. In addition to putting noise in the AC line, audio components with digital circuits pollute other components by radiating radio frequency noise, or RF, through the air. Digital circuits work with clock pulses and electronic switches that operate in the AM radio frequency range; their operation radiates this RF noise, which is picked up by other components.
In addition to introducing noise in the AC line through the power cord and radiating it into the air, components also transmit noise to other components through the AC ground line. The AC ground connects all the chassis of an audio system. If you've got a noisy ground on one component, you've got a noisy ground on all your components. For example, digital noise in a CD player's ground can get into your preamplifier, with the AC power line acting as a conduit for this noise. Noise can also get in the ground by leakage through electrolytic capacitors in power supplies.
All of these problems can be controlled with a well-designed AC power-line conditioner. First, nearly all conditioners filter the incoming AC line to remove the high-frequency garbage generated by factories, neighbors, and your own appliances. The filters allow the 50Hz AC to pass, but remove noise from the line. Second, some filters isolate the components from each other with small isolation transformers on some of the conditioner's AC outlets. These transformers break the physical connection between components, preventing noise from traveling from one component to another. The isolated outputs are often marked "digital" for plugging in digital components, preventing a digital processor from polluting the AC supplying the preamplifier, for example. Third, a good line conditioner will reduce the amount of noise coupled to signal ground. Finally, AC line conditioners can protect components from voltage spikes, lightning strikes, and surges in the power-supply voltage. Not all conditioners perform every function listed here; conditioners vary in their design principles, with some addressing one problem but not another.
Some audiophiles have separate, dedicated AC lines for their power amplifiers. This reduces the chance of distortion of the AC line caused by power-amplifier current draw from affecting the preamplifier and source components. Dedicated lines are often wired with "hospital grade" AC outlets. Running dedicated lines to your listening room can have a dramatic sonic effect. You can also improve AC power by providing a separate, isolated ground for the listening room's AC outlets. An electrician disconnects the grounds from the listening room's AC outlets, runs a wire from the ground outside your house, then pounds a copper ground rod into the earth and attaches the wire. Your audio equipment is no longer connected to the house ground.