Hifiman EF400 R2R dac balanced amp. Usb dac, high power headphone amp. EF400 uses a sought after dac technology called R2R that is known for being able to produce plenty of detail while having smooth, organic quality to the sound. It can be accessed by usb, either usb-B or usb-C on the rear panel.
The amplifier is a high power unit, producing up to 4.4 watts of output at 32 ohms. It has a fully balanced design for maximum stereo separation and features the four most common outputs on the front panel: SE 3.5mm, 6.35mm / BAL 4.4mm, XLR. Housing is metal, faceplate is thick chunk of aluminum, it looks and feels like a compact high end amp. Dials have a weighted feel as well!
The right dial is for volume while the left dial allows you to choose one of four settings for high or low gain and oversampling dac mode or no oversampling dac mode. The gain setting lets you match the sensitivity of different headphones while the oversampling lets you choose from two slightly different audio presentations from the dac, so you can better match your preferences.
EF400 is an affordable, high quality solution for harder to drive headphones like fostex t50 variations, Hifiman models, Dan Clark, 250/ 300/ 600 ohm and Audeze models.
Hifiman EF400 review: Headfonics, 8.9/10 : The DAC alone is well worth the asking price of admission here so the amplifier section seems to be a bonus item... The high current amplifier section within the HIFIMAN EF400 seems to be geared to driving planar magnetic headphones since the high current is what they crave the most in order to retain dynamics, particularly in those low notes... The 4.4 watts per channel seem capable of driving my most insensitive cans to painful levels and most cans were content with the low gain setting and at halfway volume .
(For a balanced cable for your Focal, Hifiman or Meze headphones, see the $79 or $169 Meze 4.4mm cables in the cable section. For Audeze headphones we have Audeze XLR cables in stock.)
Service was great as usual. My needs were well heard and understood before I was recommended a product. The quality of the device seems quite good. My first R2R dac, and it sounds very pleasingly different from the other ones I have used. The amp is very powerful, and my headphones could barely hit 40% dial range on low gain before they surpass my safe listening levels. I like the retro looks of it too. Being a USB only device, I wish it had dedicated drivers for PCs even though the generic ones work just fine.
The EF400n has great sound with plenty of output for most if not all headphones. It is a super match with HiFiMan headphones, as it should be. Balanced ins and outs are very well done. Fit and finish are very good for the price. If you can live with only USB B and C inputs, this is highly recommended. One item of note, I did not manage to get this unit to work with a On the Go cable adaptor.