HiFiMAN HM901u Digital Music Player
The HM901U's all new CNC alloy casing combines sleekness and high- durability. rev It prevents system crashes due to temperature issues and other disturbances. This results in largely improved system reliability.
Sound Quality Driven Technology
Secret to the Best-Sounding Experience? ES9018 DAC
The HM901U utilizes a pair of the new top-of-the-line DAC chips from ESS Technology. The ES9018 is one of if not the most impressive, high performing DAC chips available. The HIFIMAN development team spent countless hours maximizing the potential of this device, attempting to squeeze the best sound quality out of both chips, one for each individual channel.
The result is a warm and neutral sound, emphasizing phenomenal midrange reproduction, largely improving upon the dry, cold and analytical nature commonly found with other implementations with only a single ES9018 chip. As such, the HM901U raises the bar and sets a new standard for high-resolution portable audio players.
Using a pair of ES9018 chips achieves a wider sound stage and realizing extremely high detail separation.
Optimised Analog Circuit Design
The HM901U brings balanced, high quality live music reproduction straight to the listener.
1. The key to the excellent sound? 2 OPA627 and OPA2107 op-amps.
2. Instead of using the standard design in the data-sheet, the HM901U utilizes a highly optimized custom circuit design for the ES9018.
3. High & low gain modes switchable for corresponding headphone and earphone loads
Dual-Voltage Design: Doubled Divine Sound
Unlike the single battery design commonly found with other Portable music players, the HM901U utilizes a dual-voltage solution, delivering +/- 7.4 volts, 2;000 mA, and achieving outstanding results. This design helps eliminate noise from the power-supply, allowing you to focus on your music without distractions.
Advanced Step Potentiometers
The patented step analog volume control is designed for precise control and accurate channel balance. It re-moves the carbon film that tends to wear out easily. The resistors in both channels of the step potentiometer can be paired to make sure they are 100 % identical. No-gain control circuit delivers performance unmatched by the digital volume chip.
Digital volume control chips with no abatement from digital high frequency noise can result in poor sound quality. HM901U is compatible to most earphones and headphones in the market by simply changing the amp module.
Potentiometer for Volume Control
The patented step analog volume control is de-signed for precise control and accurate channel balance (with less than 0 001 in errors). The resistors in both channels of the step potentiometer are painstakingly paired to ensure that they are functionally identical. This results in excellent channel balance and soundstage. Furthermore, in order to drive earphones of high sensitivity, HIFIMAN's Advanced Step Potentiometer has a better and smarter gradual attenuation design, particularly at low volumes. This helps avoid inconsistent volume levels and channel imbalance when increasing or decreasing the volume.
Modular Amplifier Cards
Personal audio comes with headphones with high, low impedance and sensitivity, over-ear, on-ear designs. This also includes highly sensitive in-ear monitors or earphones. As such it is incredibly difficult to satisfy the various requirements of all these units with a single circuit
The HM901U features a user-replaceable slot for amplifier cards. As a result, it is now possible to use different cards to best fit the specific requirements of each headphone/ear-phone. The HM901U offers true balanced output capability, increasing resistance to interference, widening the soundstage, and improving detail and separation.
The selection for amplifier cards includes an option for sensitive in-ear monitors, and a MINIBOX and MINIBOX Gold card specifically designed for over-the-ear head-phones. The balanced card is designed for headphones with a balanced termination, often indicated with a 4-pin XLR connector.
Fully Discrete Musical Amp Card Duo with High-Res Music Player
The HM901U utilizes the all-new Musical Amp Card, the first optimized discrete component designed for a portable music player. The discrete amp card has the advantage of breaking free from the limits of an op-amp design to feature a better listening experience and higher-end performance. The HIFIMAN engineering team has achieved very fine tuning based on a long-term, wide-ranging and tedious trial and adjustment period.
The resulting Musical Amp Card reveals a mellow and silky vacuum-tube style. Not only does it pro-vide a solid ground for classical music, but it also renders vocals, jazz and small chamber orchestra even more pleasant to your ears.