Benchmark HPA4 headphone amp in black
Benchmark HPA4 High Resolution Headphone Preamp

Hailed as the world’s Ultimate Line Amplifier, HPA4 is the product of a collaboration between Benchmark Media Systems and THX Ltd.

£3499.00 inc VAT
ETA 1-2 WEEKS
SKU BM-HPA4/B
EAN 602573174142

  • THX-888 (AAA™) Headphone Amplifier
  • Benchmark Line Amplifier
  • 256-Step Fully-Balanced Relay Gain Control, 0.5 dB Steps
  • Precision Timed Relay Closures
  • Precision Metal Film Resistors
  • Gold-Contact Relays
  • Balanced and Unbalanced I/O
  • 6 Watts into 16 Ohm Headphones
  • 11.5 Vrms into 300 Ohm Headphones
  • Short-Circuit Protection
  • DC Protection
  • Over-Voltage and Over-Current Protection
  • Thermal Protection
  • Touch Screen Control
  • IR Remote Control (optional)
  • 2 Balanced Stereo Line Inputs
  • 2 Unbalanced Stereo Line Inputs
  • 1 Balanced Stereo Line Output
  • 1 Unbalanced Stereo Line Output
  • 1 Balanced Mono Sum Output
  • 2 Bidirectional 12V Trigger Ports

It is the first headphone and line amplifier to feature THX’s Achromatic Audio Amplification technology (or AAA) and reduces harmonic/intermodulation/crossover distortion by up to 40dB. The reduction is achieved by utilising a patented feed-forward topology which nullifies conventional distortion and noise mechanisms.

With HPA4, Benchmark and THX have produced a headphone and line amplifier capable of technically reaching maximum output and SPL without the usual side effect of distortion, delivering power, audio fidelity, speed and accuracy onto a silent canvas.

THD < -125 dB (0.00006%)
SNR 135 dB, unweighted, 20-20 kHz (> 131 dB THX)
SNR (A-Weighted) 137 dB (> 135 dB THX)
Frequency Response -0.003 dB at 10 Hz, -0.001 dB at 20 kHz
Impedance 60 Ohms (near 0 Ohms THX)
Output Noise < 1.9 uV at Unity Gain, 20-20 kHz (< 2.45 uV THX)
Max Input 20 Vrms (+28 dBu)
Max Output 20 Vrms (+28 dBu)
Crosstalk < -133 dB @ 1 kHz, -116 dB @ 10 kHz
Dimensions 220 x 99 x 212mm, 3.62kg