Cyrus Pre

The Cyrus Pre was our state-of-the-art component for preamplification. The Cyrus Pre was designed alongside the Cyrus Power to feature a number of innovative and no-compromise measures to fulfil the design mandate of this unique product. The perfect combination of straight line approach with microprocessor controlled operation makes the Cyrus Pre a world class preamplifier unrivalled in performance almost at any price.

The Cyrus Pre was a straight line with short path passive technology for input selection circuitry that goes a long way in establishing a sound foundation for the Pre to build on. This passive approach for signal switching ensures an undisturbed, low impedance path for the low level signals. The low current design, gold contact relays ensure zero Power supply related imprint on low level signals potentially caused by actuator coil coupling.

The high speed, discrete current feedback line amplifier provides the choice of either balanced or single-ended ultra low distortion drive to the power amplifier. Balanced drive systems are by definition less susceptible to the effects of environmental interference and are preferable over extended cable lengths where the power amplifiers are placed remote from the Pre-amplifier.

The unique power supply system designed for the Cyrus Pre makes use of low noise shunt regulation techniques, allowing each stage to be driven individually by a high impedance source, eliminating electro-magnetic radiation pickup from power supply. This also ensures zero voltage related intermodulation effects between power supply sections, that in turn can degrade the more subtle characteristics of the reproduced signal in such areas as imaging and focus.

The dual motorised volume potentiometers are calibrated to an exacting level of precision during the manufacturing process. This technique allows utilisation of the preferred passive attenuators with the added benefit of a high degree of accuracy in level control steps and channel balance. The micro-processor controlled servo drive design of the volume control, facilitates remote operation of the Cyrus Pre in a most ergonomic fashion.

Technical Information

Electrical

Line inputs –  5 + Tape
CD Balanced input Balanced Cannon input option for CD
Phono input Modular MM, upgradeable to MC with bypass option

Outputs – Tape-out, Preamp-out (RCA), Preamp-out (BAL)
Power Supply – Toroidal transformer with low noise shunt regulation
External – Highly regulated PSX-R upgradeable
Communications – MC-BUS System BUS
Remote Control – Full function remote control facility

Specifications

Output voltage (Max level) – 380mV (RCA), 775mV (BAL)
Preamp Output impedance – 100 Ohm (RCA) 47+47 Ohm (BAL)
Distortion – 0.005% (20Hz-20kHz inc. hum)
Frequency Response – -3 dB at 1Hz and 100kHz
Line input sensitivity – 200mV (RCA), 77.5mV (CD BAL)
Phono input sensitivity – MM: 2.75mV, Optional MC: 150mV
Line input impedance – 12.5 kOhm
Phono input impedance – MM: 47kOhm, Optional MC: 100 Ohm
Line s/n ratio (ref. 500mV) 105dBA – MM s/n ratio (ref. 5mV) 87dBA MC s/n ratio (ref. 0.5mV) 78dBA
Equalisation tolerance – ±0.1dB (RIAA or new IEC Equalisation)
Dimensions – (H x W x D) 73 x 215 x 360 (mm)
Weight – 3.1kg
Finish – Black

Designed & Engineered in the United Kingdom