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CD -77 Compact Disk Processor
King of Multibit" TDA1541A DAC
OptiSample® - From Digital Master to 192kHz
Revolutionary New Old Stock OptiValve® Analogue Stage
Block Diagram for AMR's CD-77: CD-Processor
At the heart of the CD-77 is the Philips TDA1541A Digital-to-Analogue Converter. Despite having ceased production over a decade ago, this chipset was selected as no other chipset comes remotely close to offering so much musical satisfaction.
OptiSignal® conditioning circuit takes the TDA1541A to the zenith of compact disk playback, so much so that the CD-77 is able to sonically outperform classic and latest compact disk sources, even those that use the same chipset.
OptiSample® offers the best possible performance for CD replay. With AMR’s appreciation that “no one sound fits all” come different sampling approaches from Digital Master to Oversampling to Upsampling. They are all user-selectable, offer different perspectives on the sound and reproduce the original recording to the highest degree. Most important of all, Digital Master I and Digital Master II which were developed by AMR and are exclusive to the CD-77 and CD-777, means they are two of only a handful of digital components able to play "bit perfect" audio. This means music, not hifi is the result because there is no artificial manipulation of the signal (so often found in almost all other machines)."


OptiClockLock® synchronises all internal clocks to the exceptional military-grade temperature compensated master clock module to avoid the creation of unwanted beat frequencies, reduce overall digital noise and resultant jitter.

OptiReg® optimises the power delivery to all digital circuits by being 1000 times more effective at cutting out noise when compared to generic power regulation circuits. Eschewing the common approach of using a few generic single-stage regulators, the CD-77's OptiReg® digital power supply circuit has 14 specifically designed regulators, most of which are two or three-stage.


OptiDrive® transport mechanism is an in-house transport design. The musical synergy was made possible through using the best genuine components - the high-precision, reliable Sony K-series laser pickup mated to the musical Phillips CD-18 servo system along with a proprietary high-torque direct-drive motor. This is all housed in a very substantial CNC machined aluminium CD well with an extra-stable CD spindle and a CNC machined aluminium CD clamp.


OptiBus® USB digital input accesses the vast library of music from a computer, allowing it to be enjoyed to a far higher level than conventional personal computer audio systems. A major reason for the impressive sonic quality is that OptiBus® ensures far less jitter than if the common S/PDIF interface was used.

OptiValve®analogue stage is a revolutionary thermionic electron valve circuit. Using no negative feedback, with high gain, very low distortion and low output impedance together with New Old Stock thermionic electron valves, the performance is simply unparalleled.
OptiCool® offers exceptional cooling characteristics without traditional heatsinks (which resonate like many tuning forks).

OptiPower® supply circuit is completely free of regulators from beginning to end. This is an essential pre-cursor for subsequent thermionic electron valve circuits operating with no negative feedback to attain the maximum sonic performance.

OptiMains® is truly one of a kind in that it will maintain the optimal voltage to internal circuits to ensure the best sonic performance (and longest tube life). This patent-pending circuit will automatically detect, monitor and adjust if necessary, the incoming voltage to ensure the correct voltage is always supplied to the relevant internal sub-sections.

OptiTrans® power supply transformers have been designed in-house and are individually hand-made. They are some of the most advanced double C-Core transformers available. Sonically, they surpass even the impressive R-Core transformers used in many high-end components and comprehensively outclass traditional EI and toroidal transformers used in many peer group products.

OptiSeal® is the galvanic sealing of functional sections which includes separate transformer windings to ensure that noise from one section does not contaminate adjacent sections. This includes naturally, a full dual-mono audio circuit design.

OptiChassis® is based upon the "ratio aureum" design principle along with an extruded aluminium chassis and a pure copper inner chassis base. The result is an unrivalled low resonance signature from optimised electrical and thermal properties.
OptiIsolate® supports were drawn from the far more exacting aerospace industry to provide maximum mechanical isolation of the solid aluminium chassis from unwanted vibrations and resonances.
AMR components use premium components chosen after extensive evaluation, lengthy and comprehensive listening tests. These include Ultra High Speed RF, military-grade design printed circuit boards, German-made premium film capacitors, AMR's own power supply polypropylene film Music Capacitors, zero noise schottky rectifiers and FEP Teflon insulated cable with silver-plate copper conductors for chassis wiring.
Information and specifications subject to change without notice.


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