Before buying these check out our repro stock in the x-demo section - a sure fire way to save some money.

http://www.moorgateacoustics.co.uk/x-demo-equipment/cyrus-psx-r-833182-169901-664017.php

Most people are suspicious of this box when first introduced to it. Don't be; the performance advantage offered by the PSX-R is dramatic and well beyond what you would expect from an upgrade at this price. Works with all Cyrus models fitted with a PSX-R port on the rear. This includes; Cyrus 3, 3i, 7, 8, Pre-amps (all) most CD players and the better power amps.

PSX-R - Power Supply
It is a widely accepted fact in the high quality audio circles that the power supply design accounts for a large portion of the overall perceived quality of the hi-fi system. The Cyrus PSX-R is a 300W fully regulated DC Power supply designed to enhance the performance of the partnering Cyrus products when used as an optional extra. With its intelligent connectivity, the PSX-R automatically adjusts its output parameters to suit the partnering Cyrus component.

• A 300VA toroidal transformer with an enormous current delivery capability forms the front end of the PSX-R. The 30,000 microfarad slotted foil reservoir capacitors ensure that very low ESR and wide bandwidth are presented to the linear mode regulator stage that follows.

• The symmetry as a design objective set out in the Cyrus range continues to be an important topology feature of this wide dual bandwidth DC amplifier working as a linear voltage regulator in an identical manner for the positive and negative sides of the PSX-R.

• Current sharing fast double output power transistors ensure quick response in providing the demanded current from the partnering Cyrus unit. Low noise high gain amplifiers in a propriety design provide the remarkable load and line regulation afforded by the PSX-R.

• The intelligent nature of the control circuitry built into the PSX-R not only sense the requirement of the partnering Cyrus component but also relinquish the power-on control to that unit to allow ergonomic operation of the system. At the same time this elegant circuit protects against mal-operation of the PSX-R beyond the designed parameters.

• Connection to the partnering Cyrus unit is made through a quality XLR cable assembly that ensures tight coupling and minimal loss in efficient and fast energy transfer. In all instances except for high current applications the PSX-R may be added into the system without any changes to the existing components and by merely plugging the unit in.

• In low Power applications such as CD or DVD players the addition of the PSX-R provides a highly stable external Power with massive inertia which ensures ideal battery like operation for such units. In high Power applications, on the other hand, the PSX-R while establishing a very stiff voltage source behind the power amplifier, it successfully inhibits mains related distortions and charging spikes from reaching the signal lines of the amplifier.

• The quality lightweight die-cast enclosure of Cyrus PSX-R has a myriad of advantages both electrically and mechanically. The integrated heatsink design enhances the thermal efficiency allowing higher performance to size ratio. Additionally, the non-resonant nature of the alloy minimises microphonic effects, while its non-ferrous composition provides an effective shield from external electro-magnetic disturbances. This also eliminates coupling of the power transformer stray magnetic fields to the sensitive audio circuitry.

Click here to read a reveiw: http://www.cyrusaudio.com/prd_downloads/XP_PHX_PSX.pdf