Cyber222 MKII , SRPP design, full remote control
Class A power supply , relay based volume control, and LED display.
Specification:
Frequency response: 2Hz-150KHz(-1B)
Signal-to-noise ratio: 90dB
Distortion: Less than 0.05%(70Hz/7KHz 4:1)
Consumption: 40W
Input Sources: 5 selectable inputs switched by gold plated relays
Input Terminals:Gold plated phono/RCA unbalanced
Output terminals: Gold plated phono/RCA unbalanced
Vacuum tube:6SN7x4 5AR4x1
Remote Control: RC-5 compatible IR system 36KHz moudulation
Dimensions: 8cm x 43cm x32cm (HxWxD)
Weight:15Kg
Featuring silver wiring, true balance inputs and outputs utilising 2X101D triodes with zero global negative feedback.
Constructed using high quality Swedish manufactured "LUNDAHL" input and output transformers,6SL7 Rectifier and 2X2A3 valves.
Special silicon steel EI type power transformers and choke with large Solen MKP metalized polypropylene filtering capacitor to obtain the widest possible frequency response.
Remote control.
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Harmonic Distortion (for 2V RMS at output)
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less than 1%
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Frequency Response
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(at -1dB) 5Hz -60kHz (Gain=9.5dB),5Hz -40kHz (Gain=15.5dB)
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Input Impedance
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600 ohms
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Signal noise
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90dB
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Gain at 1kHz
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9.5dB and 15.5dB
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Consumption
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60watt
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Negative Feedback
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None
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Vacuum Tube
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2A3x2,6SL7x1,101Dx2
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Dimensions
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430(L) x 400(W) x 225(H) mm
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Weight
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25kg
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The R50MKII is a 20dB gain line stage pre-amplifier using an improved SRPP circuit with no global negative feedback.
The capacitors used for signal coupling are the exotic US AuriCap's. All connections are point to point wiring using high purity copper hook up wire. The circuit board acts as a support frame for the tubes and other components and actual point to point wirings are done beneath the circuit board.
The power transformer and choke are shielded from the circuit board. A special silicon steel EI type power transformer and choke with good high frequency response is used together with large Solen MKP metallized polypropylene filtering capacitor.
The two tubes used in the main circuit are the fabulous sounding ECC82/12AU7. In order to match with tube power amps, the R50MKII has been redesigned based on the top model R1.1, to use components that have very little colored sound of their own, so that the R50MKII can clearly show off the sound of the tube power amp itself. A lot of satisfaction will then be achieved by trying out other exotic 12AU7 tubes like the TJ Full Music 12AU7.
Reference 1.3 is a passive preamplifier, offering a material improvement over all previous such schemes based around resistive attenuation. high performance core component for a magnetic volume control. It is a multi tapped transformer with a 20 position switch, the transformer is housed in a Mu-metal shielding can measuring 60.25mm in diameter x 72mm in height,