Интегральные усилители — SPEC RSA-EX1000

The RSA-EX1000 is an integrated amplifier from SPEC Corporation, a Tokyo company founded in 2010 that builds Class D amplifiers inside wooden chassis. Its home market price is JPY 7.2 million before VAT, and in North America it sells for USD 42,000. SPEC designs the output stage around custom Infineon FETs rather than an off-the-shelf module.

Key specs that matter

SPEC rates the amplifier at 200 W per channel into 4 ohm and lists compatibility with speakers from 4 to 16 ohm. Frequency response runs from 10 Hz to 30 kHz within 1 dB, and distortion is given as 0.02% THD at 1 kHz and 80% of rated output. Inputs comprise two balanced XLR pairs and three single-ended RCA pairs on gold-plated Neutrik sockets, and rear toggles can drop the level of one balanced and one RCA input by 6 dB. The case measures 450 mm wide, 180 mm high and 523.5 mm deep, and the power unit weighs 28 kg.

Engineering and use context

A 600 VA transformer with an R-shaped core feeds the circuit through two secondary windings, giving each channel its own supply. The main board is laid out so the signal travels the shortest possible distance from the volume control to the output low-pass filter. SPEC mixes capacitor types on purpose, placing paper-in-oil and ruby mica parts in the signal circuitry and blending several bypass types in the power supply. A stepless resistor-ladder control governs level, while a separate electronic analogue attenuator sits at the power amplifier stage. The frame uses maple side panels and a laminated spruce base, woods taken from violin construction, and the unit stands on three wooden feet, each cut from a different species. Inside, EMC paint and sheets that absorb electromagnetic waves are applied to limit interference. A remote handset works through an external receiver box with its own IEC mains inlet, and it can only turn the volume down from the position set on the front knob.

Pairing

The rated load range covers most passive loudspeakers, including low-impedance floorstanders that need current. The two XLR inputs suit sources with balanced outputs such as professional-style DACs and phono stages, and the attenuation switches let a hot source be matched to quieter ones so the volume position stays consistent when switching.

Alternatives

Within the SPEC catalogue the RSA-F33EX is the other integrated amplifier to consider, placed below the RSA-EX1000 in the line.