Power conditioners are generally much more expensive than the single parallel (shunt) units recommended above, though the cost of a good power conditioner can be comparable to the total cost of a maxed-out multiple set of parallel AC filters. The sonic improvement gained with most power conditioners is less than from either recommended set of parallel type filters and is therefore not as cost effective. We have found that many high end audio power conditioners are marginal or negative in their effect. This seems to be associated with the current-limiting isolation transformers, coil inductors and bad-sounding types of ferrite cores used in many series-filter type conditioners.

Two different power conditioner-type devices have been found so far which are major exceptions to this: (1) The Foundation Research LCI bi-directional AC noise filter system, and (2) our own Magnan Signature power cable/line conditioner units. Though moderately expensive, they greatly improve the quality of digital and to a lesser extent analog playback in similar but slightly different ways relative to the recommended handmade AC filter approach. Most importantly, these three power conditioners and the plug-in capacitive AC filters do not add any negative sonic effects along with the improvements and also work together extremely well when installed in a single system. The effect of doing this is simply stunning. The effect of series connecting the 3 different power conditioner units (using special male IEC-AC receptacle adaptors) along with using capacitive AC filter plug-ins is clearly greater than simply additive - there is a real synergy operating. The reason for that synergy is that the different filter designs in series simultaneously reduce or eliminate several separate types of noise phenomena affecting AC power.

Recommended: (1) Foundation research LCI and LC-2 AC power line conditioners. This device employs a bi-directional noise filtration system which also stops components from injecting noise back into the power line to adversely affect the system. The LCI will power source components (DACs, transports, preamps, etc.), and low-power amplifiers. The LC-2 will power most power amps up to 200 w.

(2) Magnan Signature power cable/power conditioner. This design combines in one power cable the functions of both a power cable and a power conditioner, with greatly reduced time dispersion/group delay ribbon conductors and built-in passive filtering. There are two basic models: the standard Signature compatible with all components, and the ultra-high performance Signature Bronze for source components only.

Sources: Foundation Research (905) 659-1789
Magnan Cables, Inc. Tel/fax (805) 484-9544, e-mail magnaninfo0340@aol.com