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General
Frequently asked questions about AMR equipment
Both the AM-77 and CD-77 are available in dark titanium or champagne gold. The former is a more modern and technical presentation. The latter offers a more classic and reto look. The RC-77 remote commander will be included in the same corresponding colour.
Thermionic Electron valves when used in audio circuits offer a far more musically satisfying and engaging sound than transistors (please refer to Appendix A for a more detailed explanation).
The Valves used in AMR products are qualified by the manufacturer for operation under maximum operating conditions of 10,000 hours. AMR operates the signal valves used in the CD-77 processor and the drive-stage of the AM-77 very conservatively.

U.S. military data from the 1950s suggests an average lifespan of 100,000 operational hours under such conditions. If the average listening time is 10 Hours per day this equates to around 27 Years. Individual valves may fail earlier or last longer than such average predicted lifespan.

From auditions and electrical tests, AMR found most modern production valves were inconsistent in sonic terms and quality control/reliability was poor. In the AM-77 and CD-77, the majority of Valves are NOS.

These Valves were originally manufactured and selected from production for military and communication use. Large stocks accumulated throughout the Cold War remain to secure supplies for years to come.

AMR products come factory-fitted with New Old Stock Valves that have been selected to offer the highest sound quality. However, we appreciate that changing valves may change the sound.

Please be aware that doing so may void your warranty and may very well change the sound quality of your AMR product for the worse (please refer to the Warranty section for more details).

In the case of AMR products, when a part such as capacitor or resistor has been selected for a certain section, it had to pass very stringent trials and is most likely the best available choice disregarding cost.

Therefore, replacement of parts may very well change the sound quality of your AMR product for the worse. Please also be aware that doing so may void your warranty (please refer to the Warranty section for more details).

AMR use copper and aluminium for the chassis for three reasons. First, these materials are non-magnetic. Second, they allow a relatively 'light' structure to provide the required structural integrity and freedom from resonance AMR require. Third, aluminium and copper offer excellent shielding properties. .
At AMR we machine the front panel from a 25mm thick Aluminium billet. The extruded structures for the sides are on average 10mm thick and are additionally reinforced for increased rigidity. The top plate for the CD opening is made from 5mm Aluminium. The bottom of the chassis is formed from a 7mm thick sandwich of 2mm pure solid copper and 5mm solid aluminium with the rear panel formed from a 5mm thick sandwich of 2mm pure solid copper and 3mm solid aluminium. Hence the strength of the main structure of AMR's chassis varies between 5mm to 10mm with all main structural parts being 7mm or thicker. The resultant empty case weighs in at around 18Kg and is supremely resistant to vibrations of any kind.
OptiIsolate® supports were drawn from the exacting aerospace industry to provide maximum mechanical isolation of the solid aluminum chassis from unwanted vibrations and resonances.

Therefore, your AMR component already offers superior resonance dissipation compared to peer products. However, different supports may slightly change the sound, feel free to experiment.

AMR strongly believes that its components should offer a superior sonic performance when only fed common mains electricity without the need for expensive after-market power conditioning products. Hence, AMR has integrated several unique technologies in its products to minimse the impact of mains quality.

AMR components incorporate critical electrical management designs - OptiMains®; OptiPower®; OptiReg®; OptiSeal® and OptiTrans® (please refer to the Advanced Design Features section for more details). The effect is that AMR components are minimally influenced by the constant variations in the quality of standard electrical power supply. Exotic power re-generation equipment may be of an added sonic benefit, but the increment is likely to be very limited.

After assembly, every AMR component is placed on a test bench where it is run continuously for 7 days or 168 hours. Measurements are taken all the while to ensure that it is operating within the intended parameters. However, AMR is aware that equipment tends to change in a more gradual fashion over the first 1,000 hours of operation.
AMR take measurements according to many different principles during design and quality and control. The measurements quoted in the Specifications section however, were taken according to standards established by a variety of bodies.

These bodies include the Fair Trade Commission of the U.S., the IEC and the Institute of High Fidelity. The standard applied (where applicable) is quoted with the measurement in the Specifications section.

At this stage, AMR chose CD over the competing new formats because most modern recordings regardless of their being issued as DVD-Audio, Super Audio CD® or CD have been manipulated so that they do not even start to approach the limits available from the CD format.

Many earlier recordings that have a wider dynamic range nevertheless, were engineered to fit within the capabilities of CD. Hence, at this stage, very little music material exists that takes advantage of the improvements offered by the new media standards. Therefore, AMR elected to provide a player that offers the recreation of music from the existing catalogue of recordings to the highest degree of realism.

 
   
   


     
 
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