HIFIMAN EF400

Introducing the EF400, a headphone amplifier featuring HIFIMAN's R2R architecture Himalaya DAC, delivering a sound close to pure Class A. With a maximum output of 4.4W, it effortlessly drives even demanding planar magnetic headphones, allowing you to enjoy the rich, organic sound characteristic of R2R.

[Reason for Selling]
I purchased this unit used (in good condition) in December 2025. While I was very satisfied with the sound quality and overwhelming power, the unit's size was larger than I anticipated, making it difficult to secure adequate space on my current PC desk setup.
To prevent it from going to waste, I would like to pass it on to someone who can provide a dedicated audio space for it.

[Condition and Accessories]

Operation has been confirmed.

There are no noticeable major scratches or dirt, and the overall condition is good (please check the photos for detailed condition).

Accessories: Original box, power cable, etc. (everything shown in the photos is included).

[⚠️ Note on Power Cable]
The included power cable is a 3-pin specification. If you plan to use it with a standard 2-pin household outlet, please separately purchase a 3-pin to 2-pin conversion plug (around a few hundred yen) from a home improvement store or Amazon, or use your existing audio power cable.

[⚠️ Please Read Before Purchasing: Analog Volume Specification]
This unit employs an analog volume control, prioritizing sound purity and power. Due to its design, a slight difference in volume between the left and right channels (gang error) may occur when the volume knob is turned down very low (at very quiet listening levels).
This is not a malfunction or defect, but a normal characteristic of high-output analog amplifiers.


If you are using high-sensitivity earphones or listening at low volumes, please lower the output volume on your PC or playback software slightly, and then turn the volume knob on this unit to the 9 o'clock to 10 o'clock position or higher. This will perfectly balance the left and right channels, allowing you to enjoy the ultimate R2R sound.

We would appreciate it if those who understand the characteristics and specifications of the analog amplifier as described above would consider purchasing.
Please note that we cannot accept returns due to product swapping or misunderstandings of specifications. Thank you for your understanding.