Leben RS-100 Line Pre-Amplifier

The Leben RS-100 line preamplifier uses General Electric (USA) high output tubes, 6CG7. The line pre-amp circuit consists of special selected dual-triode valves 6CG7 (General Electric / USA) by a SRPP system to improve high-frequency range of the sound and can supply a strong signal of 52V to the power amplifier.

Hum Noise Canceling Circuits: For lighting the heater of the 6CG7 tubes, DC current (12V) is applied to minimise the noise of heating and additionally a 60V bias is applied to the heater to cancel the noise caused from the heater.

Carbon Film Resistor: Leben dared to choose a custom-made carbon film resistor of +/-3% error margin to have a more natural and smooth sound instead of normal metal film resistor of +/-1% error margin which makes the sound harsh.

Direct Input Terminal: A direct input terminal goes directly to the volume control to transmit a pure signal without passing via the contact points of the selector switch, therefore a superior result is obtained when a phono preamplifier or a CD player is used through the direct input. Leben used for the direct input circuit a high audio-grade PCOCC-A shielded wire produced by Oyaide Electric Co. to achieve a pure signal transmission.

Leben RS-100 line pre-amplifier.

Highlights and Features:

• Super-precision German UXB resistor with 0.1% error margin
• 'EAO' (Germany) MKP Condensor
• 'Nichicon' audio-grade condensor "Fine Gold"
• 'ALPS' audio-grade volume for volume and balance controls
• 'Spiral Wire' for all inner wiring (very near the single structural wire)
• Two outputs: one is variable (with volume level) and the other is fixed
• Five inputs plus direct input
• REC OUT / REC MONITOR IN functions
• Muting 30 seconds after power-on
• Natural wood side panels
• RS-100 and RS-100U were designed for two different sound preferences, either 6CG7 or 12AU7 respectively but based on a same circuit design. However they are not interchangeable due to the specifics of each valve type but other compatible valves could be used. (6CG7: 6FQ7; 12AU7: ECC82, 6197 and 5814)

Leben RS-100 line pre-amp rear view.

Specifications:

• Valves: 2x 6CG7 GE (for RS-100) or 12AU7A (for RS-100U) (NOTE not interchangeable between RS-100 and RS-100U); 1 x 6X5GT (Sylvania)
• Gain: 23dB
• Maximum Output: 52V (Fixed) and 0V - 52V (Variable) - both outputs can be used at the same time, for example to add a subwoofer or bi-amping.
• Output Impedance: 600 Ohms
• Residual Noise: 0.08mV
• Power Supply: 240V / 50Hz
• Power Consumption: 23W
• Weight: 7.5 kg (approx.)
• Dimensions: 390(w) x 230(d) x 142(h) mm (Incl. side panels and feet - approx.)
• Accessories: Power cable