Specifications of LUXMAN M-7i (improved model) Luxman

LUXMAN M-7i
¥ 350,000 (around 1998)

Commentary

Improved stereo power amplifier based on M-7.
There was also a version upgrade service by board exchange method from M-7 to M-7 improved model.

It can be used not only as a stereo power amplifier but also as a monaural amplifier using a BTL connection.

The CSSC circuit which is unique to LUX based on the all-stage direct connection complimentary service circuit is adopted.
The first stage is a complimentary service circuit of dual FET differentials and cascode-connected transistors, and the second stage is a base-mounted current transmission circuit. The cutoff frequencies are sufficiently high, and the amplifier bandwidth can be secured only by the phase rotation of the first stage. Therefore, natural signal amplification without requiring sufficient phase correction is achieved.
The current amplifier stage is a 3-stage Darlington complimentary service circuit with high amplification factor, and the last stage is composed of 6 large bipolar transistors (Pc = 150W) with multi-emitter structure per channel with push-pull.

It uses OD beta circuit which is Luxman's original NFB technology.
By refining the bare characteristics, which are the basic characteristics of the circuit, we have secured DC stability that can eliminate the DC servo amplifier from the DC, which previously required strong compensation. By using the same compensation method for all bands, we have realized a unified sound flow over all bands.

The power supply section uses a high-inertia power supply that enables a flexible power supply through the development of a special electrolytic capacitor with excellent instantaneous charge / discharge characteristics. This minimizes the delay of music from real-time and provides a stable power supply.
In addition, a large-capacity toroidal core power transformer and a 22,000 μ Fx2 electrolytic capacitor are used to achieve superior response capability.

It uses LUX's unique custom-made audio resistors with improved information density and improved reproducibility at minute levels.
Based on the carbon film resistance with excellent sound quality, we have examined the selection of alumina as a solid porcelain, etching, carbonization, terminal material, terminal shape, press-fitting method, etc. to improve the amount of information transmitted.

We have reinforced internal filters to cut off noise from digital devices such as PCs, power supply noise, radio waves, etc., to reduce the influence of peripheral devices.

Equipped with a large power meter of logarithmic display system.

The input section is equipped with left and right independent Attenuator by 6-contact independent resistance switching system, and level control is possible without affecting sound quality.
In addition, the M-7 improved model is equipped with a reference position that extracts 100W output at 1 V input for ease of use when combined with various models.
As input terminals, two systems, a balance terminal and an RCA terminal, are mounted. As speaker terminals, a 3-way speaker terminal developed in-house for banana terminals and Y-lug terminals, and a Speakon terminal used in professional sound fields are also used.

Equipped with a line phase sensor that senses the polarity of the AC power supply.