HIFIMAN HM901s (Balanced) User Manual

Table of Contents

1. Package Contents
2. Product Overview
3. Getting Started
4. Using the HM901s
5. Troubleshooting
6. Frequently Asked Questions

1. Package Contents

• HIFIMAN HM901s Portable Music Player
• USB Cable
• User Manual

2. Product Overview

The HIFIMAN HM901s is a high-quality portable music player designed for audiophiles who demand the best possible sound quality. It features dual ES9018 DAC chips, a replaceable amp card design, and supports a wide range of audio formats, including high-resolution files up to 24-bit/192kHz and DSD 2.8MHz.

3. Getting Started

1. Charge the HM901s using the included USB cable. Connect one end of the cable to the player's charging port and the other end to a USB power source (computer or USB charger). A full charge takes approximately 4 hours.
2. Insert a microSD card (up to 256GB) into the microSD card slot on the side of the player.
3. Power on the HM901s by pressing and holding the power button for 3 seconds.
4. Connect your headphones or earbuds to the appropriate output jack (balanced or single-ended).

4. Using the HM901s

1. Navigate the user interface using the TAICHI II UI, which includes a scroll wheel and buttons for play/pause, previous/next track, and menu.
2. Adjust the volume using the step potentiometer on the side of the player.
3. Select high or low gain mode to match your headphone or earbud load.
4. Customize your listening experience by changing the filter response curve and replacing the amp card.
5. Connect the HM901s to a dock (sold separately) to use as a CD player replacement with remote control.

5. Troubleshooting

1. If the HM901s does not power on, ensure it is fully charged and try again.
2. If the player does not recognize your microSD card, ensure the card is formatted in FAT32 and try reinserting it.
3. If you experience audio distortion, try adjusting the gain mode or changing the filter response curve.
4. If you have difficulty with the user interface, try resetting the player by pressing and holding the power button for 10 seconds.

6. Frequently Asked Questions

1. What audio formats does the HM901s support?
   The HM901s supports a wide range of audio formats, including WAV, FLAC, ALAC, AIFF, AAC, APE, DSD, and MP3. It supports high-resolution files up to 24-bit/192kHz and DSD 2.8MHz.
2. What is the maximum microSD card capacity that the HM901s can support?
   The HM901s can support microSD cards up to 256GB.
3. How long does the battery last on a full charge?
   The HM901s has a battery life of approximately 9 hours on a full charge.
4. Can I use the HM901s as a USB DAC with my computer?
   Yes, the HM901s can function as a USB DAC when connected to a computer via the USB cable.
5. Is the amp card replaceable?
   Yes, the HM901s features a replaceable amp card design, allowing you to customize your listening experience and use third-party amp cards.

Q: What is the DAC chip used in the HIFIMAN HM901s?
A: The HIFIMAN HM901s uses two top-of-the-line ES9018 DAC chips, which are currently the most expensive DAC chips available.

Q: What is the THD of the HM901s in Line out mode?
A: The THD of the HM901s in Line out mode is 0.008%.

Q: What is the S/N ratio of the HM901s?
A: The S/N ratio of the HM901s is 106±4DB.

Q: Does the HM901s support DSD files?
A: Yes, the HM901s supports enhanced DSD (Direct Stream Digital) files with high quality playback. It can decode 24-bit 192 kHz high definition music files and offers upsampling to 24/192. It also supports DSD 2.8MHZ file.

Q: What is the battery life of the HM901s?
A: The battery life of the HM901s is 9 hours.

Q: Is it possible to replace the amplifier card in the HM901s?
A: Yes, the HM901s features a replaceable amplifier card design, which allows for more compatible designs and a chance for third-party designers to collaborate with HIFIMAN.

Q: What is the frequency response of the HM901s?
A: The frequency response of the HM901s is 20HZ-20KHz.

Q: Does the HM901s have a balanced output?
A: Yes, the HM901s features a balanced output that delivers a wide, lifelike soundstage. The driven power is four times higher under the same configuration than unbalanced output.

Q: What op-amps are used in the HM901s?
A: The HM901s uses OPA627x2 and OPA2107x2 op-amps.

Q: What is the weight and dimensions of the HM901s?
A: The HM901s weighs 7 ounces and has dimensions of 4.61 x 2.83 x 1.06 inches.