Hi all! I'm a newbie in the headphone world and got new gear as a tip from a friend to mix my home studio record: a Hifiman400se headphone + a Douk Audio U3 amplifier. I know the gear isn't supposed to be neutral at all, but I figured with reference tracks being played through the same system, I could find myself.

Now what I did NOT expect was that the headphone's OWN sound would vary so much. The onset of the signal seems to be randomly and viciously cut, just like a compressor with a fast attack and soft knee would.

Has anyone heard anything like this before, about this gear or other gear? Is this normal? I'm at a loss and don't even know what to call it!

 

I agree with clone for sure. I actually got a super cheap douk and returned it, then went to the local hifi shop just bought some used headphones amp.

 

Spoiler: ai

What you’re describing isn’t normal for the HE400SE or the Douk Audio U3. Those headphones are usually very linear and shouldn’t “cut” the onset of signals like a compressor. Check your connections first—loose cables can cause dropouts. Also, test different audio files and playback software, in case any DSP or volume leveling is affecting the sound. While troubleshooting, it might be a good idea to shop noise-canceling headphones as a comparison to see how other gear handles transients. Double-check the amp’s gain and mode settings, and if possible, try the headphones on a different amp (or your amp with other headphones) to isolate the issue. It could be a rare defect, but these steps usually help pinpoint the problem.

 

Last edited by a moderator: Sep 29, 2025

Edit: just noticed our friend who I've quoted actually not only is posting AI answers, but is also necroing old threads. FFS. Disregard my effort below.

The Hifiman is a planar headphone, and you're running a planar headphone through a very cheap amplifier that promises 1300mW at 32 ohm (the impedance of the headphones, actually). At Audio Science Review, someone claims that the actual measured wattage is 509mW, almost a third of what was promised. Still, that should be enough for these headphones in particular, but there's a good chance your amplifier is the weak link here. I would just test it on a better amplifier.

https://www.audiosciencereview.com/...mplifier-measurements-found-on-youtube.57389/

Are we really posting AI answers without following the spoiling rules now?

 

Every single one of his posts is AI generated/rewritten by AI.