Angstrom Research

MAINS FILTERS

Passive filters are a valid element for suppressing disturbance in the domestic electricity mains, where electrical appliances of all kinds, such as halogen lamps, etc, create a "dirty" electricity main, causing alterations to the final result offered by your hi-fi system.
People sometimes think that a direct line specially for the system solves every problem, but this isn't so. It can help reduce the problems but it doesn't eliminate them as the disturbance returns in circulation, especially when the separate line isn't served by a second meter.
Many people use mains decouplers in the belief that they eliminate every kind of disturbance, while in actual fact there are numerous problems regarding their use. They generate authentic inductions and create a dreadful final result due to the fact that they "choke" the electricity supply, which often becomes apparent in that sense of closed sound.

An effective way of cleaning up the electricity supply is the use of passive filters which house no transformers (active components), only inductances (passive components). Angstrom Research filters are made with RCL cells (R= resistance C=capacity' L=inductance) in double or triple stage when a higher slope is required to eliminate the worst disturbance. The inductances used can be DIFFERENTIAL (single inductor) or COMMON MODE (inductor on the sole nucleus of which there are two phase/neutral windings). These are responsible for the correct operation of the filter and must be chosen carefully in order to achieve the results required.
The largest possible inductance values must be chosen because, generally speaking, the higher the electric impedance at high levels, which increases in proportion to the L product and drops when the effect of the capacity distributed by the winding starts to become apparent, the greater the efficiency of an inductance.
Exceptional importance is also held by the condensers (CLASS X2-Y2-CX-CY-Y1) which must have very low levels of electricity leakage to eliminate broadband disturbance. The condensers are connected serially to resistances which eliminate disturbance produced by contacts (switches, fridge motors, etc...).
The resistances perform a dual function, reducing oscillations and preventing damage to the condensers when a high density disturbance is discharged inside, creating auto-oscillation phenomena.
In the RC circuits, the optimum values of the resistance depend on the capacity of the condenser, the power supply voltage and the operating current.
All the pieces must be positioned at distances which prevent them from interacting and therefore generating disturbance. Exceptional quality condensers are used with double metal-coated paper and double metal-coated polyester film with absolutely no induction power.
All the components are selected by hand before being assembled. The cabling is strictly SUSPENDED and extreme care is devoted to this selection, especially with regard to the high working temperature AWG 16 cables, with inner capacity and resistances compliant with MIL-AWM1569-105C/1007.
The filter has stages with totally separate power supplies for stereo/mono, preamplifiers, cdp, dac, etc.... The aim is to prevent each appliance from spreading induction to the others (for this purpose it is very important to properly earth the electricity main).
Our filter respects all CE standards and has all related certification.
Given its exceptional reliability, it comes complete with a 5-year warranty.

The advantages of fitting our mains filter, as well as those already mentioned, such as the elimination of audible crackling on the diffusers when switches are used, buzzing cause by electrical appliances and radio frequency, can be identified in better three-dimensionality and an obvious sense of clarification of the acoustic scene.

Available in three versions:

-Reference 3: three stages, one of which dedicated to amplifiers (recommended in systems with stereophonic amplifiers)

-Reference 4: four stages, two of which dedicated to amplifiers (recommended in systems with monophonic amplifiers)

-Reference 4 HC: four high ampere stages (recommended in systems with high current absorption appliances)

Features:

-all models have six dedicated outputs with multiple sockets (extensible to order)

-dimensions in mm: 484L x 460P x 155H (the HC version is 195 mm high)

-weight in Kg: 20 model 3; 22 model 4; 30 model 4HC