The HIFIMAN EF100 is a powerful hybrid headphone amplifier and integrated amplifier. Housed in its compact chassis lie three independent amplifier sections: a vacuum tube input stage works as a shared preamp, a Class AB headphone amplifier, and a Class T speaker power amplifier. Benefitting from vacuum tube technology, both headphone amplifier and power amplifier sound warm, smooth, detailed and musical. Working as a hybrid headphone amplifier, EF100 can produce a 2w output under a 32 ohm load so it can easily drive many high performance headphones. In addition, EF100 can also serve as a hybrid power amplifier to drive speakers of moderate to high efficiency. In power amplifier mode, the amplifier output line is fully independent from the digital amplifier line used in the headphone amplifier. Driven by front stage?s vacuum tubes, EF100 combines the warmth vacuum tubes are known for with the high efficiency of a digital amplifier. It is the best of both worlds. When EF100 is used as a power amplifier, it can give 4.5 watts per channel so it can drive HIFI speakers of moderate to high efficiency. At last, with its versatile design EF100 can bring music to life from a variety of sources for both headphones and speaker applications.
Sound
As mentioned, all the impressions were done with the stock tube which actually turned out to be a pretty good one. The EF100 is dead silent: there is no single trace of floor noise or hiss with full sized headphones and the volume dial is completely silent too. The volume pot works with clicks and I'm hardly a fan of that. I never had the need to turn it over 8 clicks with any of my headphones yet I would have preferred a non-stepped pot or more clicks for better volume fine tuning. The internal DAC in all honesty isn?t that great and I used it mostly with the HERUS as DAC. Compared to the internal DAC that resulted in more detail and increased musicality.
Specification:
- Weight : 2.5 kg (5.51 lbs)
- Dimensions : 203 mm x 203 mm x 84 mm
- DAC Chip : CM102S
- Headphone Amplifier : Power Output per Channel: 1W (32O) Frequency Response: 20 Hz-20 kHz (? 0.2dB)
- Power Amplifier Output : Vacuum Tube: 6N3 (Military Class) Power Output per Channel: 4.5 W (4 O) Frequency Response: 20 Hz-20 kHz (? 1dB)
- Power Supply : 110V/220V
- S/N : 96 dB
7 day warranty
