Introducing the HIFIMAN EF400 Balanced Desktop DAC/Amplifier!

[peterinvan]

I have a problem with the ef 400, with my grade 325e at low impedance, at very low volume you hear only on the right and slowly raising the volume I hear a small disturbance on the left and then the audio starts, is this normal?

Many dual potentiometers are not perfectly matched t the lowest settings.
There is too much gain on the EF400 for sensitive phones like Grados, even on low. And the output impedence is too high.
I have ordered an iFi ieMatch4.4 to see it that addresses the volume control issue.

 

[Johnfg465vd]

Many dual potentiometers are not perfectly matched t the lowest settings.
There is too much gain on the EF400 for sensitive phones like Grados, even on low. And the output impedence is too high.
I have ordered an iFi ieMatch4.4 to see it that addresses the volume control issue.

I bought a Topping NX7 to use with my HiBy RS2 and have also tried pairing it with my EF400 which does help with sensitive IEMs interms of volume range.

This is not an inexpensive solution though so please share your thoughts on using the IEMatch with the EF400 when you get yours.

 

[dlelikov]

With regards to the power issue, that it turns out is because hifiman is apparently going by 10% THD instead of 1%. Hence a considerably higher number.

With regards to the phase issue, I talk about why this is occurring in detail at the end of the written post. Its an issue with design in terms of how the dual dac architecture is handling the I2S signal causing one channel to be exactly one digital sample behind the other. It's not a QC/single unit thing.

https://headphones.com/blogs/reviews/hifiman-ef400-review-measurements

L7 Audio Lab has also tested the EF400 and shown the same issues

https://www.l7audiolab.com/f/hifiman-ef400/

I can say that in NOS mode, localization of instruments becomes difficult, especially violins, when listening to a symphony orchestra. The instruments seem to be out of focus. This, as I understand it, is just due to the phase shift, especially strong at high frequencies?

 

[terrykok02]

@GoldenOne appreciate your review. Out of curiosity, what is your take on the OS mode? I saw there are couple reply mentioning that OS mode have a different presentation.
Thanks

 

[boodi]

the OS mode seems wetter then the NOS , NOS is drier and looser for stage
OS mode has tighter bass and sounds tighter in general
NOS has more bass not a night and day thinhg , noticeable though ; there's a slightly larger base .

OS seems more precise almost through all frequencies , NOS little more relaxed
upper frqs on OS are slightly more pronounced , higher highs can sound slightly more sibilant / show a pitch depending on music

just my ears for what it counts ..

 

[Nooborghini]

From @GoldenOne ’s Disc:

UPDATE: Hifiman has issued a recall for EF400 units affected by the interchannel phase issue. They have offered to send a fixed unit and I’ll have an updated followup review coming once I’ve received and tested it. Info about affected serial numbers will be provided as soon as possible.

The man doing the lord’s work. Thank you mate

 

[dlelikov]

it would be nice if a representative of the company would make a comment on this issue in this forum thread, which is located in the announcements of sponsors section.

 

[peterinvan]

109 Pro Treble

I found that the treble on my Meze 109Pros diminished after about 100 hours. For my old ears, the high end on these phones suits me just right

I tried the HiFiMAN EF400 and found that the impedance was too high, so the volume control was at just above minimum. The highs were also emphasized, so I returned the EF400, and I am satisfied with the sound quality from my sightly warmer FiiO M11Pro.

 

[cirodts]

Is there a solution to that annoying hissing noise when I turn up the volume with low impedance headphones like grado?

 

[Nooborghini]

I emailed HiFiMan CX service and they said they aren't doing a recall.
I'm not sure if I should just return this thing and call it a day. @TeamHiFiMAN any word?

Are you or are you not doing a recall on EF400s

 

[cirodts]

is there a recall on the ef400 for the issue of noise on the volume?

 

[Johnfg465vd]

is there a recall on the ef400 for the issue of noise on the volume?

No, it's something to do with phase in higher and lower frequencies being out of sync (IIRC) that was discovered by goldensound a few posts back.

 

[cirodts]

explained in simple words?

 

[elwappo99]

I emailed HiFiMan CX service and they said they aren't doing a recall.
I'm not sure if I should just return this thing and call it a day. @TeamHiFiMAN any word?

Are you or are you not doing a recall on EF400s

I would just return it. There's no clear message from HFM about when the units will be fixed or how exchanges will happen. On top of that, there's no guarantee it'll actually be fixed and resale value of the EF400 will go down a lot. If you're still in a return window I'd use it.

 

[juannycash]

I would just return it. There's no clear message from HFM about when the units will be fixed or how exchanges will happen. On top of that, there's no guarantee it'll actually be fixed and resale value of the EF400 will go down a lot. If you're still in a return window I'd use it.

As much as I love the sound so much, the OS sampling light flickers and goes out periodically regardless of source or cans hooked up. Shipped her back today. What’s the next step up for a similar sound? I’m auditioning an RME and while it’s great and clean, I’m pretty much hooked on that analog sound now!