Интегральные усилители — ToneWinner AD-66D

Tonewinner of Guangzhou makes the AD-66D as a stereo integrated amplifier with a Class A output stage, a built-in Analog Devices converter, file playback from storage media and a Bluetooth receiver. The company presents it as a cost-effective Hi-Fi power amplifier within its range, and the chassis is sold with silver or black front and case colours.

Key specs that matter

Tonewinner gives distortion of no more than 0.025 percent at 1 kHz, an A-weighted SNR of 95 dB minimum, and channel crosstalk is at least 75 dB. Gain is 38 dB with a tolerance of 1 dB, and maximum voltage gain is stated as above 40 dB. The DAC chip is the Analog Devices AD1955, which decodes PCM streams up to 24 bit and 192 kHz and carries a chip rating of 120 dB for both noise and dynamic range. The case measures 444 x 436 x 107 mm and runs from mains of about 220 V.

Engineering and use context

The Class A power stage is built on two pairs of Toshiba TTA1943 and TTC5200 transistors. A custom toroidal transformer supplies the circuit, and the filter bank uses capacitors totalling 15,000 uF. Volume is handled by a JRC NJW1194 high-precision stereo control chip that adjusts level in 0.5 dB steps. Digital inputs include a Mini USB audio port for a computer, a USB-A host port and a Micro SD slot for playing files from storage, HDMI with ARC, one Toslink optical input and three coaxial inputs. Wireless sources connect over Bluetooth 4.2 through an ATS2825 receiver chip. Three stereo RCA sockets make up the analogue input section, and the power stage is specified for 8 ohm loads.

Pairing

Alongside the speaker terminals there is a stereo RCA subwoofer output, so a powered bass unit can be added to form a 2.1 system. The HDMI ARC input accepts the audio return channel of a television, and the Mini USB port takes a computer as a digital source. Tonewinner's own passive bookshelf speakers include the TD-7SE and the TD-3, both 8 ohm designs, so a system can be assembled from a single maker. The company also produces CD players with optical and coaxial outputs for use with the digital inputs.

Alternatives

Tonewinner's AD-86D is a stereo integrated amplifier rated at 2 x 120 W, with a built-in preamp that can be switched between integrated and independent operation and eight Toshiba output transistors.