Cyrus Tuner mkI

The advent of digitally synthesised tuners has substantially improved the reception quality of FM broadcasts. A few problems however continue to persist in the design of most Fm tuners. The most serious of these problems we consider to be sibilance in high frequencies and poor low-frequency performance. It is common knowledge that the low-frequency performance of tuners lacks authority, control, definition, and articulation - especially when compared to the latest generation CD players.

The objectives of Cyrus Electronics have been to produce an outstanding tuner where the FM section does not suffer the nagging problem of "spitting" sibilance, and to give bass notes their rightful and necessary musical weight, tempo, and authority. The Cyrus Tuner is manufactured in a case of identical dimensions and appearance to the rest of the Cyrus range, and will suit the requirements of the perfectionist audiophile who owns either a Cyrus One or a Cyrus Two.

The design is based on microprocessor controlled digital frequency synthesised tuning,, and provides 19 FM and 9 MW preset with C-MOS memory back-up. The unit provides variable speed up/down scanning, automatic search, as well as manual tuning. Automatic FM mute is provided to eliminate irritating interstation noise. Quartz-locked tuning system is adopted for ultimate tuning accuracy and minimal frequency drift. An informative Fluorescent Tube Display electronically generates digital frequency readout, "Tuning " indication, "Stereo" reception and, when selected, preset channel number. For finest reception quality under adverse signal conditions the Cyrus Tuner has FET front-ends (dual-gate with automatic gain control on FM). The FM mixer oscillator is buffered to ensure high immunity to interference, and Ceramic filters are incorporated for high selectivity on both AM and FM wavebands. The Cyrus Tuner offers "Sliding Stereo" decoder maintaining full channel separation on strong signals, and changing gradually to mono for fullest noise suppression on weak signals. PLL decoder circuitry produces a stable audio signal with optimum channel separation, and an SISC filter cuts out interference on stereo broadcasts.

Specifications

FM Section

Frequency Range:  87,5 - 108 MHz

Frequency Response:  20 Hz - 15 kHz ±1 dB

Audio Output:  1 V RMS

Sensitivity (75 Ω input)

Mono :  0,8 µV (26 dB s'n)

Stereo ;  18 µV (46 dB s'n)

Selectivity:  72 dB

IF Suppression:  100 dB

Image Frequency Suppression:  57 dB

Pilot Tone Suppression:  43 dB

Stereo Separation (1 kHz):  36 dB

Signal-to-Noise Ratio

Mono :  73 dB

Stereo :  71 dB

Total Harmonic Distortion

Mono :  0,15%

Stereo ;  0,4%

Aerial Input:  75 Ω coaxial

AM Section

Frequency Range:  513 - 1611 kHz (186 - 584 m)

Audio Output:  0,3V RMS

Sensitivity:  130 µV (26 dB s'n)

Selectivity:  58 dB

MF Suppression 52 dB

Image Frequency Suppression:  58 db

Aerial Input:  External loop Aerial and External Connection Socket

Dimensions (W x H x D):  215 x 85 x 340 mm

Weight: 2 kg

Cyrus One amplifier

The Cyrus One is based on a revolutionary circuit design philosophy, details of which are beyond the scope of this blog and in any case well guarded secrets. The design is then implemented with careful attention to circuit topology in order to minimise the number of components in the signal path and reduce their harmful effects. This 'straight-line" design is then manufactured to the very highest standards using components and materials beyond the reach of most competition. The power transistors, for example, are military grade, ultra-fast and very linear devices especially manufactured for Cyrus Electronics. The driver transistors are equally products of a British military semiconductor manufacturer. World class german produced passive components have been selected including extravagant polypropylene capacitors, polystyrene capacitors, and metal film resistors. The casing for the amplifier is precision injection moulded from a "non-magnetic", "non-electroconductive" metal substitute produced by Space Division of American General Electric.

All spurious and harmful stages, such as tone-controls and filters, headphone and loudspeaker switching, protection circuits and balance controls have been eliminated to make the amplifier a "straight-line", no compromise, state-of-the-art. Design. The quality control standards are amongst the highest in the industry where every amplifier is tested along nearly 100 parameters on the most sophisticated hewlett-packard CAD-CAM systems available. The result is an extraordinary achievement called the Cyrus One integrated amplifier, elegant in appearance, without gimmicks, and capable of producing a breathtaking and spectacular sound stage when used with quality ancillary equipment.

Specifications

Power Amp. Section

Continuous Average Power: 

30 watts per channel both driven into 8 Ω

40 watts per channel both driven into 4 Ω

Current Delivery:

10 amps RMS continuous

40 amps peak to peak instantaneous

Damping Factor;  100 (20 Hz - 20 kHz)

Dynamic Headroom:  1,4 dB

Slew Factor:  10 (input filter by-passed)

Distortion

Full Power into 8 Ω 0,004% :  (1 kHz); 0,01% (20 kHz)

Full Power into 4 Ω :  0,005% (1 kHz); 0,015% (20 kHz)

Preamp Section

Input Sensitivity

Phono MC :  0,04 mV

Phono MM :  0,400 mV

Line :  65 mV

Input Overload (1 kHz)

Phono MC :  27 dB

Phono MM :  27 dB

 line ;  Infinite

Maximum Output Level

Tape Out :  11 V RMS

Power Amp :  17 v RMS

Input Impedance

Phono MC :  47 k Ω  +100pF

Phono MM :  47 k Ω +100pF

Line :  14 k Ω

Output Impedance

Tape Out :  10 Ω +2,2 µF

Power Amp :  0,08 Ω

Frequency Response :

Phono (ref. New RIAA) :  20 Hz - 20 kHz ±0,2 dB

Line :  1 Hz - 55 kHz -3 dB points

Total Harmonic Distortion

Phono MC :  0,02%

Phono MM :  0,005%

Line :  0,004%

Distortion (SMPTE IMD)

Phono MC :  0,02%

Phono MM :  0,005%

Line :  0,005%

Signal-to-Noise Ratio (A-weighted at 1 W):

Phono MC :  66 dB

Phono MM :  82 dB

Line :  86 dB

General Section

Dimensions (W x H x D):  215 x 85 x 340 mm

Weight:  4 kg

Cyrus One

Product Overview

Traditionally budget amplification was considered to have “budget sound”. The appearance of the Cyrus One in 1984 upset this established norm and revolutionised the audio industry. It demonstrated unequivocally, that an audiophile integrated amplifier was well within the grasp of the music lovers without the funds to indulge in exotica.

Designed by Cyrus to handle demands of modern loudspeakers and wide bandwidth recordings, the Cyrus One featured an exceptional power supply capable of responding to the source material requirements. This is the heart of the amplifier, the source of its stress free sound.

Further Information

To keep the signal as pure as possible, the Cyrus One features ‘minimalist’ circuitry devoid of the non-essential stages which interrupt the signal path. The signal integrity is preserved, even through this short path, by the use of only the finest components, including military grade power transistors and selected passive elements.

The cabinet and chassis are designed to do more than just elegantly cover the Cyrus interior: the case itself is made from a precision diecast non-ferrous metal alloy, while the chassis with integral heatsink made of diecast aluminium. In addition to structural integrity not demonstrated by any other amplifier at or near the Cyrus price range, these features improve the sonic fidelity by dispelling mechanical resonances, circuit microphony and airbourne radio frequency interference.

The Cyrus One has the capacity to accept five separate signal sources serving as the basis for a comprehensive hi-fi system. With its minimalist appeal and compact dimensions, the Cyrus One allows the listener to record from one source while listening to another and will accept the signal from high quality moving-coil cartridges as well as from the more common moving-magnet types. It is a completely functional package, providing the essentials without compromise.

Specifications

Continuous power:

25 W/CH (both driven into 8 Ohms)

40 W/CH (both driven into 4 Ohms)

Distortion:

0.005%, 1 kHz (into 8 Ohms)

0.007%, 1 kHz (into 4 Ohms)

Frequency response (line input): -3 dB, 1 Hz and 50 kHz

Frequency response (phono RIAA): 20 Hz – 20 kHz ±0.2 dB

Damping factor: 100

Slew rate: 10

Sensitivity (reference 1W output):

MM: 400uV, MC: 40uV, Line: 65mV

Input impedance: 14 kOhm (RCA), 47 kOhm (PH)

Maximum output voltage: 11 V (Tape out)

S/N Ratio (reference 1 W output):

MM: 84 dBA, MC: 67 dBA, Line: 86 dBA

Dimensions (H x W x D): 85 mm x 215 mm x 345 mm

Weight: 4 - 5 kg (depending on version)

Finish: Black or grey

Cyrus Two

The Cyrus Two set the standard for ultimate audiophile amplification. Designed to eliminate the extraneous aberrations caused by non-essential circuitry, the straight line Cyrus Two was “the” integrated amplifier for the persuit.

Amplification power is commonly defined in “watts” rating. In order to boast elevated specifications, amplifier manufacturers, in an increasing battle over specs, pushed their wattage ratings upwards at the expense of poor current delivery.

The Cyrus engineers defined high current swing capability as being the most important criteria in amplifier design. This is due to the reactive nature of loudspeakers requiring high currents rather than current-starved wattage. Being able to deliver currents demanded by the loudspeaker readily ensures true reproduction of the complex musical signal. At 50 Watts per channel the Cyrus Two can swing a substantial current of 60 Amps peak to peak.

The Cyrus Two incorporates a truly refined moving coil phono stage with excellent noise figures and minimal hysteresis, designed to work esoteric cartridges often costing many times as much as the amplifier. The direct CD input of the Cyrus Two eliminates unnecessary components that would otherwise interfere with the fidelity of compact disc reproduction.

But it does not stop there, for music lovers demanding even greater power, the Cyrus Two can be upgraded with the addition of the Cyrus PSX outboard power supply.

Specifications

Continuous power:

50 W/CH (both driven into 8 Ohms)

80 W/CH (both driven into 4 Ohms)

Continuous power (with PSX connected):

70 W/CH (both driven into 8 Ohms)

125 W/CH (both driven into 4 Ohms)

Distortion:

0.003%, 1 kHz (into 8 Ohms)

0.004%, 1 kHz (into 4 Ohms)

Frequency response (line input): -3 dB, 1 Hz and 50 kHz

Frequency response (phono RIAA): 20 Hz – 20 kHz ± 0.2 dB

Damping factor: 100

Slew rate: 10

Sensitivity (reference 1 W output):

MM: 0.3 mV, MC: 0.02 mV, Line: 50 mV

Input impedance: 14k (RCA), 47k (MM), 100k (MC)

Maximum output voltage: 11 V (Tape out)

S/N Ratio (reference 1 W output):

MM: 84 dBA, MC: 75 dBA, Line: 86 dBA

Dimensions (H x W x D): 85 mm x 215 mm x 345 mm

Weight: 4 - 5 kg (depending on version)

Finish: Black or grey

Cyrus Tuner

Cyrus Tuner (Original Versions)

Product Overview

An often overlooked but rewarding source of readily available program material is radio. Cyrus, being based in a country where radio broadcast quality is of the highest order, designed a tuner to enhance the pleasure attainable from live concerts, plays and other programmes available over the airwaves. The Cyrus tuner is a microprocessor-controlled, digitally-synthesised design employing a high quality phase-locked-loop circuit which ensured tuning precision and low distortion.

Further Information

Engineered to the same high standards as its stablemates, the Cyrus One and Two the Cyrus tuner featured separate regulated power supplies for the digital, RF and audio sections and a powerful toroidal transformer to enhance the sonic performance of the audio output section. The Cyrus tuner had a unique automatic setup facility that, when accessed, scans the entire waveband, entering into its memory all stations with adequate signal strength. Other details incorporated to make the Cyrus tuner a truly functional design included full-function remote control, a 10-digit keypad for instant access to frequency and preset selection, facilities to store 59 FM and 59 AM stations, display on/off for interference-free reception, remote power on/off, remote volume operation and a host of other convenience features.

Specifications

Wavebands: AM & FM

FM Input Sensitivity:

30 dB S/THD+N, Mono – 1 uV (11 dBf)

50 dB S/N, Mono – 1.7 uV (16 dBf)

50 dB S/N Stereo – 18 uV (36 dBf)

Total Harmonic Distortion at 1 KHz: Mono 0.15%, Stereo 0.15%

Ultimate Signal to Noise Ratio: Mono 82 dB, Stereo 75 dB

Capture Ratio: 1.5 dB

Remote Control: 22 Functions

Volume Control Range: ±3.75 dB (1.25 steps)

Net weight: 5 kg

Dimensions (H x W x D): 215 x 350 x 85 mm