Интегральные усилители — Kora TB200

The TB200 sits in the middle of the three Square Tube integrated amplifiers made by Kora in Toulouse, above the TB140 and below the TB400. The TB200 accepts line sources only, with no phono section, and its French price is EUR 11,760. Weighing roughly twice as much as the smaller TB140, it moves to a heavier power supply and a much larger bank of output devices.

Key specs that matter

Power reaches 2 x 100 W into 8 ohm and 2 x 180 W into 4 ohm. There are four stereo RCA line inputs, each with 15 kOhm impedance and 1 V sensitivity. Input 4 has two optional roles - as a bypass input it turns the integrated into a power amplifier, and as a pre-out after the volume control, with 2 kOhm impedance, it can drive an active subwoofer. Frequency range is 20 Hz to 20 kHz within 1 dB, and output impedance is below 0.08 ohm. With feet and sockets the unit measures 148 x 420 x 350 mm, the bare chassis 130 x 420 x 320 mm, and it weighs 19 kg. Peak consumption is 310 W at full 8 ohm power and 610 VA at full 4 ohm power, on 230 V mains or 117 V to order.

Engineering and use context

The Square Tube stage uses two ECC82 and two ECC83 double triodes, giving four triodes per channel, and it performs all of the voltage amplification. Twelve complementary ON Semi transistors, rated 225 W and 15 A apiece, deliver current to the loudspeakers without adding gain. Two 300 VA transformers feed 2 x 60,000 uF of filter capacitance and rails of plus and minus 50 V DC, while the valve circuits run from stabilised +300 V and -200 V supplies. Auxiliary voltages come from five DC/DC converters and two linear regulators, and both input and output tubes are heated from 12 V DC. The main switch is under the front edge on the left, beneath the engraved Kora logo. Kora advises waiting a few minutes after switching on before starting the amplifier, so its pre-charge circuit can settle. Level is set from 00 to 80 by turning the single front knob or with the metal remote supplied, and a menu on the knob offers left and right balance plus a gain offset for each input. Cabinet materials are aluminium and steel in mineral grey, backed by a five-year warranty.

Pairing

Line sources such as the Kora CD140 or DAC140 connect straight to the RCA inputs, while a record deck has to go through an external phono preamplifier. In bypass mode the TB200 can take the RCA output of a PR140 preamplifier.

Alternatives

The Kora TB400 is the larger integrated model above it, rated at 2 x 200 W into 8 ohm and sold for EUR 17,040 in France.