The HPA-1 headphone amplifier was designed ground-up to become what we believe is one of the very best sounding headphone amplifiers available today. With low feedback, wide bandwidth and a direct coupled MOSFET output stage, this musical instrument drives even the most difficult headphone loads with ease, power and grace. The HPA-1 also functions as a line-level preamplifier that sonically rivals much higher-priced competition. The measured performance is superb and the sound even better.
Like the XP preamplifiers, the HPA-1 is the result of great attention to detail.
Starting at the power cord, the AC line is first filtered for high frequency noise and then isolated by a special toroidal transformer shielded by mu-metal for lower magnetic noise and shielded for electrostatic noise by a separate Faraday shield, grounded to analog ground. This is followed by fast/soft recovery rectifiers, generous CRC passive filtering and sophisticated discreet DC regulators and then more passive RC filters.
- Works with headphones with impedances of 15 ohms to 600 ohms
- Low feedback wide bandwidth discreet design.
- Class A direct coupled Mosfet output stage
- Custom low noise Torodial power transformer with a Farady shield
- Discreet regulated power supply for audio circuits.
Gain (dB) 8 dB
Power Consumption (W) 23
Output Power into 20 ohms 3500 mW
Output Power into 300 ohms 200 mW
Frequency Response 10hz -100k -1 dB
THD + Noise < 0.005 at 1V out
Input Impedance 50K Ohm
Output Impedance < 2 ohms