HIFIMAN EF400 DAC Balanced Desktop Headphones and Amplifier with Himalaya R2R DAC, 3.5/4.4/6.35mm Output for Home Audio, Silver

It’s a dumb DAC/AMP that sounds fantastic and is very powerful that has no remote or Bluetooth capabilities and doesn’t compete with others in this range but if you don’t care about those features then this is still a solid high end choice. It’s super powerful and I don’t even need to push my headphones past 25% volume. It’s mean to be used with a computer but a phone or iPad will work fine as well. I am using it as part of my meditation setup and running Moondrop Para planars. For convenience I added a WiFi tp link Kasa power adapter that I control through my phone when I want it to turn on / off daily.

I don't have any of the issues like static noise or limited volume control with iems, that some people have mentioned. The sound is wonderful, clear, deep with wonderful decay. A lot of value for the money. Even tried it as a dac only in my main stereo setup. It is truly amazing and makes you question other products you may have paid much more for.

This unit must be used with a PC source. When connected to my iPad Pro as a source, NOS mode produces crackling noises throughout any CD-quality tracks. Engaging OS mode makes the crackling go away, but NOS is the preferred mode for myself and most other EF400 owners. After contacting Hifiman, they say there is no fix for this nor any firmware update in the works. The device does not appear to be firmware updatable at all. That being said, it does have a great sound and is a great performer despite this annoying issue. I prefer using my iPad Pro as a source over my gaming PC as it is cleaner and quieter source, and it works perfectly with all my other DACs and DAC/Amps. There is a quirk with this device with its NOS mode for 44.1 sample rate tracks when connected to lower powered source devices such as iPads, so be aware of this and only purchase if you're planning to use with a PC/Mac source.UPDATE: I figured out how to fix the NOS mode buzzing issues, which seem to only happen on CD quality tracks when using an iPad or iOS device as source. The way to fix it is to use Roon and turn on Sample Conversion and set it to Max. I went back and forth turning it on and off and it really does work, made the buzzing go away, and the buzzing comes back when you turn it off. Glad I finally found a workaround. Still was not convenient and cost me extra to purchase Roon.

It is an incredible value to get a balanced R-2R DAC and a balanced headphone amplifier with this kind of power for this price. Especially one that sounds this good.The sound is better than the Monoprice THX 887 (which I think sounds decent but not fantastic). And, I am a firm believer that specs don't tell the whole story when it comes to sound quality- how a device responds and measures in terms of THD, noise, and response with a static test signal into a static load is a poor predictor of sound quality. For example, the Topping A90 measures extremely well but sounds lousy IMO.This is a very good sounding device. It has the warm, natural R-2R character. It sounds better in NOS mode, unlike my Musician Pegasus R-2R DAC which I prefer with oversampling on. There is less detail and separation compared to the Pegasus, especially in the lower mids on stacked vocal harmonies. But still very good. To me, OS mode has a bit of the glassy, constrained sound of a lesser dac. All oversampling digital filters are not created equal, and I'm not terribly fond of this one. The good news is, with oversampling off, I don't perceive much of a loss in high frequency as a result of filter slope affecting the audible band as I do on the Pegasus.I like my music loud, and this powers hard to drive headphones quite well, including my HEDD Heddphone, and my HE-6SE, although the HE6 could benefit from more power if you like your music loud and with slam. But don't get me wrong, it is really good, and phenomenal for the $There is a slight metallic nature to the timbre of upper treble, like hats and cymbals, but it is minimal and it is the only detracting sonic coloration i can perceive in this unit.Now here is the problem- there seems to be some kind of minor design flaw in the DAC.When I play lossless FLAC files I ripped directly from the original CD, verified bit-perfect rips, I can hear static in both ears, similar to a dirty vinyl record, on quiet passages when in NOS mode. Switch to OS mode and the problem instantly goes away. Play an M4A/AAC compressed version of the same file and there is no problem in either OS or NOS mode (i ripped all my CDs into both FLAC and M4A files).I am using USB Audio Player Pro for Android in Bit-perfect mode on a Samsung Galaxy Note 20 Ultra as my source, via USB-C.I don't have this problem on ANY of my other USB DACs, including R-2R DACs in Non-oversampling mode such as the Musician Pegasus.I figured I may have a defective unit, so I ordered a replacement, and the replacement device does the exact same thing.And, I just noticed another reviewer complaining about the exact same problem. That review is spot on.I've knocked the unit 1 star for this, otherwise it would be a slam dunk 5 stars at this price.

I have owned the $5000 Audiovalve Solaris, the $5500 Pathos Inpol Ear, the $2k+ ifi iCAN Pro, and others. I also own the Topping DX7 Pro and others. I am convinced that this product is not only the best value amp or amp/dac on the market, I'm not convinced it gets much better than this at any price. Maybe for VERY hard to drive cans like Susvara, but this can drive even those to a great degree. Even if you use it ONLY as a DAC, it's probably the best value DAC on the market.They easily could have charged $2k+ for this product.It would be great to have an upgraded version that had IIS in and out, allow external DACs for fun, etc, but honestly the price is ridiculously low for what you get.Muscular bass, beautiful tone, great precision and soundstage, sounds great with every headphone I try. Just fantastic. A MUST BUY.I currently am using it as the DAC (and partner amp) for my Pathos Inpol Ear, and it is an even better match for the Pathos than the highky regarded $1k+ Musician Pegasus R2R DAC, adding tighter and harder hitting bass, precision etc.