Review: The Bit Audio Opus#1 – Mouth Korea

Sound

Even a coddled Millenial progressive should be able to discriminate Oppy’s quality output. It’s a warmish take on a familiar trope: rich and comfy. Here and there both lead and trail edges round out otherwise sharp niches. Midrange stereo image is larger and more lifelike than low and high stereo image, which really focuses the listening experience and provides pretty damn good depth.

Its singular ouchy, hiss, is innocuous by AK100 standards, but obvious against the black backgrounds of the Cowon Plenue D and AK380. Low-volume listeners with high-sensitivity earphones may notice it. I hear it through both my FitEar MH335DW and Ultrasone IQ. (By the way, FitEar’s new MH334DW SR, about which I wrote a small bit here, is a damn fine earphone.)

Oppy nails all the important bits: stable current for a stable frequency response, wide stereo separation, and controlled distortion curves. It does this both at low volumes, and at volumes typically used to test a device’s theoretical output limits.

In general, Oppy performs.

That is: it performs especially well as you’re using its single-ended out. SE out keeps both THD and IMD distortion levels comfortably below audibility. Frequency dips are miniscule. Oppy’s biggest audible anomaly is its penchant to compress low and high frequency stereo detail under load. The outcome? Beautiful, well-illustrated midrange landscapes.

Most of that compression occurs when listening through highly-sensitive, low-impedance balanced armature earphones. Driving most portable headphones incurs only a small performance penalty.

Oppy’s balanced output isn’t bad per se, but it is seriously embarrassed by MST’s Mojo-Kai. It drives loads far better than does AK380’s balanced output, and holds a steadier frequency response under load than does the DP-X1, but next to its single-ended output, it is poor. IMD jumps by 500x, and is audible at volume levels from loud to whatever a non EU-capped iPhone 6’s maximum is. THD levels jump 154x their base, but should be inaudible. There’s a hair difference between the DP-X1’s distortion levels and Oppy’s. Where there isn’t is in frequency response, where Oppy handily smacks around the Onkyo. Loaded, the DP-X1 loses 5 or 6 decibels by 20.000Hz, and Oppy keeps signal strong, if somewhat warbly, till 20.000Hz. Unloaded, the DP-X1 embarrasses everything. But what’s the point of that?

At theoretical listening levels, Oppy’s balanced output is kick-in-the-pants good. SM2-loaded stereo separation jumps from ~ -88dB to ~ -112dB – incredible both theoretically as well as in empirically. At low to normal listening levels, most of that difference evaporates. People that listen to average decibel levels in excess of 90dB will find Oppy’s balanced output to give an extra kick in stereo imaging. The rest is academic.

If you’re into well-ordered, even-Stephen stereo images and frequency responses, and balanced output is of chief importance to you, check out Ryuzoh’s Mojo-Kai. If you’re prepared to accept minimal load anomaly, and at a more pocketbook-friendly price point, it’s hard not to recommend Oppy.

My system returns the following unloaded single-ended measurements at +6dB @VOL149 (the most stable no-load volume level):

-115,1dB noise level
115,1dB dynamic range
0,0006dB THD
0,010 IMD+Noise%
-114,6 dB stereo crosstalk

My system returns the following unloaded balanced measurements at +6dB @VOL149 (the most stable no-load volume level):

-115,5dB noise level
115,7dB dynamic range
0,0059dB THD
0,011 IMD+Noise%
-111,5 dB stereo crosstalk

No, it doesn’t return unloaded numbers that wow quite like the AK380 or DP-X1, but loaded it edges out either player’s distortion levels at theoretical comparison levels. And, it returns a somewhat warmer, easier-listening sound.

Vs your favourite high-end DAP

If only its hiss was lower (it isn’t high), I’d wholeheartedly recommend Oppy to the person looking for a high-end DAP without the high-end price. As it is, hiss is barely audible with music playing at low volumes through the most sensitive of earphones.  As long as that person realises that it doesn’t get quite as loud with 600Ω headphones, there’s almost nothing to do but recommend this player. It sustains good current under all loads, almost nails gapless (with both lossy and lossless formats), and its UI, while not pretty, is easy to use, and well designed for touch input. Yes, its battery sucks, but so does the battery life of every high-end DAP out there.

End words

To be honest, I didn’t expect much from Oppy. Its stylistic flourishes are simpleton. Its nomenclature sophomoric. But it is easy to use, it sounds great, and in general it performs. If you’re not into using external amplification, it is a great choice for most earphones and headphones. No, it doesn’t get as loud as an AK380 or DP-X1. But it kicks out a stable, solid signal, and is warmer certainly than the AK380, which makes for a unique signature and it is a far better realistic platform for balanced earphones.

This Korean player lacks Korean edges, but nails SQ in a high-end world dominated by Korean DAPs.