Leben Hifi Components

Leben CS600X is a integrated tube amplifierHandcrafted in Japan by Leben Hi-Fi Stereo Company, a small manufacturer founded in 1992 by former Luxman engineer Taku Hyoda. Direct heir to the celebrated CS600 from 2005, this model represents the natural evolution of the project: the circuit revision has allowed the now unobtainable NOS 6CS7s to be replaced with modern 12AU7A e 12BH7A, ensuring production continuity and reliability over time, as well as a slightly warmer and more musical timbre than its predecessor. 

The sound heart is made up of a quartet of power valves 6CA7/EL34 in configuration push-pull class AB, capable of delivering 28W per channel at 1 kHz. Optionally, it is possible to mount 6L6WGC/5881to obtain 32W per channel, acting on the internal switches that regulate plate voltage (410V/450V) and cathode resistance (460Ω/680Ω). The amplifier also accepts KT66, KT77, KT88 and 6550A valves, offering a voicing flexibility that is rare in this product range. The circuit self-bias (self-polarizing) frees the user from technical adjustments when replacing tubes: simply insert the chosen tube and listen.

The input stage is made in configuration SRPPwith Mullard phase inversion section, while the power supply section employs a 6CM3/6DN3 valve rectifier with a 5 Henry damping impedance, a solution that allows for a gradual increase in voltage and significantly extends the life of the power tubes. The transformers—both mains and output—are wound internally at the Leben factory: a fundamental detail, since the quality of the transformers is the true sonic limit of any tube amplifier. The wiring is made point to point, thread by thread, as tradition dictates.

On the rear panel, the impedance selector allows you to choose between 4, 6, 8 and 16 ohm taps, allowing for optimal adaptation to any type of speaker, including the rarest 16-ohm ones. The correct setting is generally the one that sounds “fullest and most present,” a sign of maximum energy transfer to the load.

On the control side, the front panel offers a traditional but complete setup: five-position input selector (Line 1, Line 2, CD, Line 3, Line 4), tape monitor loop for three-head or cassette recorders, switch Stereo/Reverse for channel inversion, mute, balance control and a refined Two-position Bass Boost (+3 dB and +5 dB)acting below 100 Hz, achieved through a feedback network rather than a traditional tone control: a more musical and less invasive solution on the midrange, protected by a 15 kΩ resistive filter. The 40-position volume knob allows for precise and repeatable adjustments.

The switch Normal/Pre In allows you to bypass the preamp stage and use the CS600X as a pure power amplifier, ideal for those who want to combine it with a tube preamplifier or a separate line. The headphone output is taken directly from the output transformers, ensuring reference-level headphone listening quality, a behavior not taken for granted even with high-end integrated amplifiers.

The cabinet combines a metal housing frame with side cheeks in Canadian white ash, a hard, dense wood traditionally used for baseball bats and racing oars: its mass contributes to vibration control, together with the anti-vibration feet derived from the superior CS1000P model. With its 23 kg weighing 450 x 360 x 142 mm, the CS600X has a deliberately retro aesthetic, without a remote control, without an integrated DAC, without a phono stage: a purist product intended for those who prioritise musical substance over accessory functions.

The sonic character is that of a classic high-school Japanese tube amp: rich and correct timbre, dense harmonic texture, tactile articulation on acoustic instruments, round and full bass, silky and never aggressive mid-highs. It's an amplifier that reveals all its value on jazz, classical repertoire and vocals, but is also perfectly at home with well-recorded rock and pop. How to connect a tube amplifier to a turntable? Since the CS600X has no phono stage integrated, it is necessary to interpose an external phono preamplifier with RIAA equalization, connecting the arm ground to the GND terminal on the back.

Produced in small annual batches and distributed with limited availability, the CS600X is intended for an audience of discerning listeners looking forhi-fi tube amplification an authentic product, built to last decades and capable of growing over time through tube rolling and micro-voicing changes.

Leben CS-300XS is a integrated tube amplifier da 2x15W which embodies the finest Japanese high-fidelity craftsmanship. Built entirely by hand, it combines a refined retro aesthetic with the sound quality that has made the Leben brand famous among tube sound enthusiasts. The gold-anodized front panel, oversized knobs, and side panels in Canadian ash make it a cult object for those seeking musicality and aesthetic character in a single component.

The heart of the circuit is made up of four Sovtek EL84 valves in configuration push pull, piloted by two 12AX7A Sovtek in the driver stages. The auto-bias circuit simplifies maintenance by automatically adapting to valve variations, eliminating the need for recalibration when replacing pipes. point-to-point wiringwithout PCB, the 24K gold-plated valve basesand custom output transformers developed by Leben for an extended high frequency response, they demonstrate an uncompromising construction approach.

On the front panel there are three large selectors for input, balance and a useful selectable bass boost at +3dB or +5dB, ideal for adapting the response to drier speakers or small rooms. The output dedicated headphones driven directly by the valve circuit, it offers a very fine grain and surprising control even with high impedance transducers. It does not lack the tape monitor, a function that is now rare but precious for those who use reel-to-reel tape recorders or external processors.

On the back there are five line-level RCA inputs, four terminals WBT for speakers and a rotary selector for thevariable output impedance 4Ω/6Ω/8Ω, which allows you to optimize power transfer based on the connected load.

Listening to the sound reveals a rich and natural tonal balance: full-bodied mids, prominent vocals with exceptional three-dimensionality, silky highs that are never aggressive, and controlled bass. The soundstage remains stable and deep even at low volumes, a typical characteristic of the best. hi-fi tube amplifiers. After a 10-15 minute warm-up The sound opens up completely, revealing microdynamic details that many higher-end solid-state amplifiers can't deliver with the same ease. Jazz, female vocals, acoustic music, and classical chamber music are the genres where the CS-300XS shines.

The Leben CS-300XS represents a modern classic in the panorama ofhandmade tube hi-fi: a compact yet substantial integrated amplifier, built to last and designed for those seeking emotionally engaging sound. It's the ideal component for building a quality system around efficient speakers, with a quality/price ratio that's hard to match in its category.

Content courtesy of Audiocostruzioni