LEBEN RS-28CX

Valve Preamplifier

The Leben RS28CX is a reference preamplifier, designed with extraordinary attention to technical details and a musical quality that few other devices can match. This model, with an MM phono stage and a CR-type equalizer, is the result of the ingenuity of Taku Hyodo, founder of the Leben Hi-Fi Stereo Company, whose background as an acoustic guitarist has helped create amplifiers that are true works of sonic art. The RS28CX preamplifier is designed to deliver a crystal-clear and natural sound, without the addition of negative feedback (NFB), which helps avoid the undesirable colorations typically found in other devices.

The RS28CX is equipped with a CR-type equalizer based on GE (General Electric, USA) 12AT7 tubes, compliant with the J.A.N. (Joint Army & Navy) military standards. Compared to NFB, this type of equalizer provides much more stable audio reproduction, particularly in the high-frequency range, offering superior sound quality. The NFB-free design helps preserve exceptional transparency and unprecedented dynamic response. The end result is a sound that not only faithfully reproduces music but makes it resonate naturally and enveloping.

To ensure no compromise in sound quality, the Leben RS28CX is equipped with a separate power supply unit, which protects the CR equalizer from negative effects and optimizes audio performance. Additionally, the preamplifier is built with the highest quality components to ensure that the RIAA curve remains extremely precise, with a deviation of less than +/-0.3%.

One of the most impressive features of the RS28CX is its extraordinary output capacity. Thanks to the use of the General Electric (USA) Dual-Triode 6CG7 tube in the line stage circuit, the RS28CX is capable of generating a very high output voltage, up to 80V—almost double that of a traditional preamplifier. This power allows it to drive high-sensitivity power amplifiers with a clean and strong signal, offering unparalleled control over sound reproduction.

The preamplifier is also equipped with a 5-step attenuator to eliminate any residual noise coming from the speakers, ensuring an interference-free sound. Additionally, the RS28CX features two outputs (one fixed and one variable) to accommodate the integration of a subwoofer into the audio system.

With a design that combines musical experience and technological innovation, the Leben RS28CX is the perfect choice for those looking for a preamplifier that goes beyond simple technical quality, offering sublime sound performance. The combination of impeccable design, top-quality tubes, and obsessive attention to detail makes the RS28CX an essential tool for true music lovers who settle for nothing less than the best.

Technical Specifications:

Tubes:

• 2 x 6CG7 (General Electric)
• 2 x 12AT7 (General Electric)
• 1 x 5Y3WGT

Mono Amplifier:

• Gain: 20.2 dB

RIAA Curve:

• Deviation: less than ±0.3 dB

Maximum Input:

• 400 mV (at 2 kHz)

Line Amplifier:

• Gain: 25.2 dB

Maximum Output:

• 80 V (variable)
• 80 V (fixed)

Output Impedance:

• 580 Ohms

Noise:

• 0.03 mV

Weight:

• Main unit: 7.0 kg
• Power supply: 6.5 kg

Dimensions:

• Main unit: 352 (W) x 240 (D) x 175 (H) mm
• Power supply: 233 (W) x 240 (D) x 175 (H) mm

Included Accessories:

• AC power cable
• Power supply connection cable