Review: MyST PortAMP II & PortaDAC 1704 – contrast


Sound – PortAMP II

Despite being the most powerful battery or mains headphone amps I’ve used, PortAMP II’s backgrounds are almost as clean as a Vorzüge PURE II. So much power behind such little noise is almost unheard of. And, every watt of that is usable with even the most sensitive earphones. Like LinnenberG’s Maestro, its attenuator balances channels with digital precision from the lowest of volumes. That said, PortAMP II will never take your music down to 0dB output. PortAMP II leaves a bare whisper of music in the background at its lowest volume. Amazingly, you’ll have to rotate it almost 360º before it takes sensitive earphones to a comfortably loud listening level. And there are many further turns left for all your other headphones. This is unprecedented control.

PortAMP II’s only downside is that it is pretty easy to top out its power input. I’m unable to feed a signal beyond 116dB  from Mojo or other DAC into PortAMP II without returning clipped peaks.

Despite obvious load effect, stereo detail both on the X and Y axis is phenomenal and immersive. Transitions are seamless. If you’re a high-volume listener, PortAMP II parses SNR and dynamic range just north of 114dB. It keeps stereo crosstalk separated by up to -94dB on a signal which I measured at -116dB. While this is lower than CD-quality, it is 94dB. How much recorded music reveals less crosstalk than -94dB I have no idea, but I assume it is rare. Additionally, an average listening volume of, say 90dB, will cap every single metric anyway, to 90dB. Which is why I’m comfortable saying: advantages of 24-bit audio and hi-res players dissolve prior to and after hitting play.

That out of the way, PortAMP II resolves the shit out of your music. It resolves signals far lower than 20Hz and far higher than 20kHz. And at every stereo crosspoint, it gently presses signal into the next plot, slightly favouring midrange stereo openness, with lows and highs marginally trailing. The difference between each, however, is hardly notable. Cozoy Rei’s stereo gradient is even more gradual, but nowhere near as powerful, nor as smooth-sounding.

Not that PortAMP II is necessarily aiming for smooth. It straddles the line between smooth, and mildly cutting cutting. It follows the line cut best by Vorzüge’s PURE II. And yet it is far more powerful.

PortaDAC 1704’s sound after the jump:

4.5/5 - (8 votes)

Back before he became the main photographer for bunches of audio magazines and stuff, Nathan was fiddling with pretty cool audio gear all day long at TouchMyApps. He loves Depeche Mode, trance, colonial hip-hop, and raisins. Sometimes, he gets to listening. Sometimes, he gets to shooting. Usually he's got a smile on his face. Always, he's got a whisky in his prehensile grip.


  • Reply December 20, 2016


    link to eng version of site. But it’s not filling 🙂
    Beter use russian version

  • Reply December 21, 2016


    How do you compare it to Duet? I am about to buy Duet + Yulong Sabre D18 for my T90.

    • Reply December 21, 2016

      ohm image

      No comparison. But if you need balanced, DUET it is. Otherwise, this is far better.

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