Предусилители — Luxman CL-38uC

The CL-38uC is a vacuum tube control amplifier from Luxman, the Japanese company that launched its first tube integrated amplifier, the SQ-5A, in 1961. Its look is modelled on the CL-35 preamplifier of 1970, with a wooden case around a chassis of the standard 440 mm width, and it adds balanced line inputs that the maker describes as new to this model.

Key specs that matter

Five input types are listed - phono MM, phono MC high, phono MC low, line and balanced line. Sensitivity and impedance are 2.0 mV at 47 kohm for MM, 0.3 mV at 100 ohm for MC high, 0.08 mV at 30 ohm for MC low, and 190 mV for both line inputs, at 50 kohm unbalanced and 20 kohm balanced. Rated output is 1 V at 300 ohm. The phono section holds within 0.5 dB from 20 Hz to 20 kHz, and the line stages reach from 10 Hz to 70 kHz at -3 dB. Distortion is 0.006% or less at 1 kHz and 0.06% or less over the full audio band. Signal-to-noise ratios with IHF-A weighting are at least 68 dB for MM, 63 dB for MC high, 60 dB for MC low and 100 dB for line. The valve line-up is three ECC83S and five ECC82. Power consumption is 35 W, and the unit measures 440 x 169 x 307 mm and weighs 13.3 kg.

Engineering and use context

Every stage uses SRPP, or shunt regulated push pull, circuitry, which Luxman chose for a flat frequency response, low output impedance, low distortion and longer valve life. The tubes come from JJ Electronic, picked for reliability, long service life and ease of operation at the voltages and heat levels found in tube amplifiers. The built-in phono equaliser takes magnetic and moving coil cartridges alike, and each of the two MC settings has its own step-up transformer, chosen with a lever switch for MC impedance. A gain selector with two steps works independently on the left and right channels in MC mode. The balanced line input also runs through dedicated transformers. Tone adjustment spans 8 dB up or down, with three selectable turnover points per control, 150, 300 or 600 Hz for bass and 1.5, 3 or 6 kHz for treble. A low-cut filter at 30 Hz with a slope of 6 dB per octave reduces rumble from records. A compact aluminium RA-25 remote handles volume.

Pairing

The built-in MM and MC stages mean a turntable can be connected without a separate phono preamplifier, and the two MC impedance settings cover both low and higher output moving coil designs. The low output impedance lets it drive the inputs of solid-state and tube power amplifiers alike, including the companion Luxman tube power amplifier modelled on the MQ-60 of 1969.

Alternatives

The Luxman C-900u is a transistor preamplifier in the range that uses LECUA 1000 volume control and a balanced four-module circuit.