Balanced Headphone Amplifier


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The AT-BHA100 balanced headphone amplifier is designed to deliver unmatched audio quality from high-resolution sound sources, and is ideal for use with hi-fi headphones such as the ATH-ADX5000, ATH-MSR7b, and those in the ATH-AW Series. This compact desktop unit is compatible with Direct Stream Digital (DSD) and other high-definition formats to reproduce every detail of the original recording.

The AT-BHA100 features a hybrid system of vacuum tubes and power transistors to enhance the beauty and warmth of amplified sound. It employs four completely independent amplifier circuits, a high-quality New Japan Radio MUSES8820 operational amplifier, and specially designed low-noise relay switches to emphasize the depth and warmth of vacuum-tube sound. A four-layer board structure with high-quality audio-grade components from Nichicon, WIMA, and Shinyei Capacitor ensures rich, natural audio.

The amplifier is equipped with a 4.4 mm TRRS jack and a 4-pin XLR terminal, plus a low/high gain selector switch, allowing it to accommodate a wide range of balanced headphones with varying sensitivities and impedances. It also has two 6.3 mm (1/4") outputs with independent volume controls that can be used simultaneously for comparative listening.  



  • Hybrid system with vacuum tubes and power transistors enhances the beauty and warmth of amplified sound

  • Four independent JJ Electronic ECC83S preamp vacuum tubes deliver superb depth and sense of presence in the amplified sound

  • Four power transistors (one for each powered amp circuit) are capable of high-power performance to handle the wide dynamic range of sound sources with high sampling rates

  • Completely independent four-circuit structure, with separate left/right amplifier circuits and balanced hot/cold circuits, helps suppress crosstalk for a rich sound field

  • High-quality New Japan Radio MUSES8820 operational amplifier highlights the depth and warmth of the vacuum-tube sound

  • Specially designed low-noise relay switches offer excellent dynamics that emphasize the spaciousness and vibrancy of the sound

  • Nichicon chemical capacitors contribute to the low-frequency characteristics of the audio, leading to powerful bass

  • WIMA and Shinyei Capacitor film capacitors create smooth, low-distortion sonic characteristics for natural, clear sound

  • Four-layer board structure, with independent layers for signal circuits, power circuits, and ground circuits, ensures greater signal stability for rich, low-frequency control

  • Low/high gain switch offers support for a wide range of headphones with varying sensitivities and impedances

  • Two balanced outputs – 4.4 mm TRRS jack and 4-pin XLR terminal – are compatible with a wide range of balanced headphones

  • Two 6.3 mm (1/4") outputs can be used simultaneously with independent volume controls

  • RCA line-through output allows for switching between headphones and powered speakers

  • All sides of the amplifier are vented for improved dissipation of heat and a superior signal-to-noise ratio through reduced thermal noise

  • Compact unit can be set up vertically or horizontally

  • Large-capacity external AC adapter separates the power supply from the main unit for reduced noise


Headphone Amplifier
Corresponding Headphone Impedance 16 – 600 ohms
Instantaneous Maximum Output Level 6.3 mm headphone output (10%, 1 kHz): 680 mW + 680 mW (16 ohms load) 320 mW + 320 mW (32 ohms load) 240 mW + 240 mW (64 ohms load) 30 mW + 30 mW (600 ohms load) Balanced output (10%, 1 kHz): 1,500 mW + 1,500 mW (16 ohms load) 1,200 mW + 1,200 mW (32 ohms load) 800 mW + 800 mW (64 ohms load) 120 mW + 120 mW (600 ohms load)
Frequency Response Line input: 10 Hz – 100 kHz (0, -3 dB at 32 ohms 10 mW output); Balanced input: 10 Hz – 100 kHz (+0.5, -3 dB at 32 ohms 10 mW output)
Total Harmomic Distortion <=0.25% (20 Hz - 20 kHz at 32 ohms and 1 mW output)
Gain 6.3 mm headphone output: 10 dB (high gain), 1.5 dB (low gain) Balanced output: 16 dB (high gain), 7 dB (low gain)
Noise 6.3 mm headphone output: -100 dBv (A-weighted high gain), -103 dBv (A-weighted low gain) Balanced output: -92 dBv (A-weighted high gain), -95 dBv (A-weighted low gain)
Separation Between Channels 6.3 mm headphone output: 75 dB (load: 32 ohms, 1 kHz) Balanced output: 100 dB (load: 32 ohms, 1 kHz)
Analog Input Connector Line input (pin jack) x 2 Balanced input (XLR combo connector) x 2
Output Terminals 6.3 mm stereo headphone output × 2 CLR 4-pin balanced stereo headphone output 4.4 mm balanced stereo headphone output Line output (pin jack) x 2
Input Selector (front panel) Line input, balanced input
Output Selector (front panel) 6.3 mm headphone output, balanced output (4.4 mm/XLR 4-pin)
Power Supply 100 – 120V AC, 50/60 Hz, 15V DC/2.4 A (AC adapter provided)
Power Consumption 25 W (max)
Dimensions 44 mm (1.73") H × 210 mm (8.27") W × 266 mm (10.47") D (excluding protrusions)
Weight 1.8 kg (63.5 oz)
Accessories Included AC adapter, power cable, feet (6), stands (2)