TONEWINNER AD-66D

The Tonewinner AD-66D is a high-performance two-channel Hi-Fi stereo amplifier designed for audio enthusiasts seeking a compact yet powerful solution. Based on the AD-66Pro and equipped with a high-quality audio decoder, the AD-66D supports local playback from TF cards, USB drives, and other digital sources, while also offering mobile APP control for easy and intuitive operation. Its professional audio decoding chip ensures high fidelity and low distortion, delivering excellent musical performance with detailed and engaging sound. With over thirty years of experience in acoustic product design and manufacturing, Tonewinner confirms its position among the top ten audio brands in China, offering products recognized internationally.

Aesthetically, the AD-66D stands out with its two-tone white and black aluminum front panel, featuring a glossy and matte finish, a V-shaped groove in the center, and a black VFD display that glows with a soft blue light when powered on. The power button on the left and the volume knob on the right feature a luminous effect, adding elegance and attention to detail. The front panel includes a USB port for digital playback, while the rear houses a Bluetooth antenna, highlighting the amplifier’s ability to decode and transmit high-quality digital signals.

Internally, the AD-66D is powered by a differential amplification circuit combined with a specialized Class A circuit, designed to adapt its operating point to the input signal. This configuration provides extended Class A power and a broad Class A/B output range while eliminating the crossover distortion typical of Class B and reducing heat dissipation from Class A. The input stage, with single-ended input and double-ended output, ensures low noise and significantly increases voltage gain, while the common-base circuit further optimizes gain and frequency response, ensuring stability, dynamic range, and low harmonic distortion.

The amplifier employs two pairs of high-power Toshiba TTA1943/TTC5200 transistors, delivering up to 80 W per channel into 8 ohms or 135 W per channel into 4 ohms. High-quality ELNA RBD and custom electrolytic capacitors, with capacities up to 15,000 µF, provide low current leakage and high resistance to voltage and temperature fluctuations. Volume control is handled by the NJW1194 chip, which guarantees extremely low noise and channel separation up to -120 dB, allowing precise treble and bass adjustments in 0.5 dB steps. The integrated Bluetooth 4.2 module, featuring the ATS2825 chip and DSP processor, supports stable connections up to 30 meters, even during the use of TF cards or USB drives.

Key features include USB, optical, coaxial, and analog audio inputs, support for TF cards up to 128 GB and major audio formats such as WAV, FLAC, and AFE, high-speed stable Bluetooth connectivity, HDMI-ARC compatibility, mobile APP control for source selection and treble/bass adjustment, subwoofer output for 2.1 setups, and the ability to convert the integrated amplifier into a power amplifier via the U-link connection.

The AD-66D delivers a clean, rich, and natural sound suitable for various musical genres. Bass reproduction is deep, continuous, and well-balanced, while the treble is transparent and bright, with clear instrument separation. Overall, it provides a warm yet analytically precise listening experience, offering engaging and faithful reproduction of the original recording.

Technical specifications:

• Signal-to-noise ratio (SNR): ≥95 dB (A-weighted)
• Frequency range: 20 Hz – 80 kHz (+1/-3 dB)
• Total harmonic distortion (THD): ≤0.025% (1 kHz, normal operation)
• Output power: 85 W × 2 RMS/8Ω (THD=1%, 1 kHz)
• Nominal impedance: 8 ohms
• Gain: 38 dB ±1 dB; maximum voltage gain: >40 dB
• Crosstalk: ≥75 dB
• Power supply voltage: ~220 V (50 Hz)
• Net weight: 10.6 kg
• Dimensions: 444 × 88(107) × 401(436) mm (W × H × D)