Усилители мощности моно — Concert Fidelity ZL-200FX2

The ZL-200FX2 is a monoblock power amplifier created by Masataka Tsuda for his Japanese brand Concert Fidelity. It is a solid-state MOSFET design built to order, with the company describing it as an idealist, minimalist and non-compromise design with close attention to parts selection, layout and construction. Price is quoted on request through the company's distribution partners.

Key specs that matter

Each monoblock delivers 180 W into 8 ohm and 260 W into 4 ohm. Connection is by RCA only, with an input impedance of 47 kohm, and 2 V of input brings the amplifier to rated power. Voltage gain is 20 dB. Measured at 0.125 W, frequency response runs from 0.5 Hz to 30 kHz with no deviation and extends to 100 kHz at minus 0.8 dB. Power consumption in operation is 240 W at 120 V AC. Each chassis measures 450 mm wide, 180 mm high and 480 mm deep and weighs approximately 35 kg.

Engineering and use context

Concert Fidelity aims for the simplest possible circuitry with the smallest number of components. The output stage uses four pairs of MOSFETs per monoblock wired as a bridged BTL output, and the amplifier runs with no overall negative feedback. In the related ZL-120FX2 the company describes the FX updates, which bring Japanese DC-DC converters into the input and driver stages together with a revised driver board and grounding layout, and it explains that such converters isolate the stages electrically, unlike linear regulators, which lowers the noise floor. The smaller model takes over the power supply section of the ZL-200. Transformers are wound to order for the target market, covering 100 V, 110 to 120 V, 220 to 230 V and 240 V, and the maker does not guarantee operation at other voltages or cover failures outside the destination country under warranty.

Pairing

As a monoblock, two units are required for stereo. The single-ended input suits preamplifiers with RCA outputs, such as the brand's own CF-080LSX series line stages or the valve CLS-050 Mk2, and a 47 kohm input places little demand on valve output stages. With its output rising as impedance halves, the amplifier is specified for 4 ohm loudspeakers as well as 8 ohm designs.

Alternatives

The Concert Fidelity ZL-120FX2 is the smaller MOSFET monoblock in the Reference Series, using two pairs of output devices per chassis in BTL form and weighing approximately 20 kg.