Holo Audio Bliss

Broad agreement that it is exceptionally quiet: both benches put its noise among the lowest of any headphone amp, and reviewers and owners report a black background with sensitive IEMs at any volume, because the amp lowers its own gain at low settings. The exceptions are small — one owner heard brief relay static at a few volume steps and a faint hiss near the top of the range with a 2.3-ohm IEM, and one reported mechanical transformer hum. IEM users should note the 4.4 mm jack's 2-ohm output impedance (the XLR's is near zero).

“for IEMs the bliss does wonderfully, sitting alongside the lowest noise amps from topping for example”

GoldenSound

“Not only is this the cleanest fully-discrete Class-A amplifier out there, but it’s quite possibly the cleanest headphone amp, period.”

Sandu Vitalie · soundnews

“信噪比达到了117dB左右”

Soomal (“the signal-to-noise ratio reaches about 117 dB”)

“No matter what you plug in, the background is pitch black.”

Exekuhtor · Head-Fi

Sources split on the hardest loads. The bench confirms the rated 12 W into 32 ohms with low distortion even at high output, and one camp finds it drives everything up to the Susvara and Abyss with headroom to spare. The other camp — including two editorial reviewers and several owners who sold it — finds it audibly runs short of dynamics on the Susvara, DCA's flagships or a RAAL. The split largely follows the source: the volume tops out at +12 dB of gain, so with a standard 4 V DAC the amp runs out of voltage before it runs out of power, and owners who feed it 5.8–8.5 V report the punch returns.

Sources split three ways, in the classic argument. Both benches show very low distortion and a flat response, and most editorial listeners hear a clean, near-neutral amp that is never sharp. A sizeable group of owners and one video reviewer instead hear audible warmth — a liquid, slightly smoothed sound with a softened top octave (one called it upside-down-U shaped). A small group heard no difference at all from a far cheaper amp. Several owners note the impression shifts with the DAC, and many pair it with Holo's own warm-leaning May.

Broadly praised: two balanced inputs plus RCA, XLR4, 4.4 mm and 6.35 mm outputs, a preamp section reviewers rate close to dedicated preamps, and a Lo-Z/Hi-Z output-impedance switch. The automatic gain staging means no gain switch to manage. The quibbles: the headphone and preamp outputs share one volume setting, there are no tone, balance or crossfeed controls, and the remote is only included with the KTE.

“The versatility trophy goes to Bliss.”

HeadMania

“Discovering Bliss’s preamplifier is every bit as good as its headphone amp is an unexpected bonus.”

Richard Barclay · The Ear

“it would be nice if it remembered volumes of different outputs”

Rayon · Head-Fi

Mixed, leaning negative. It is big (430 mm wide, 10 kg) and runs hot as a Class-A design — the maker advises against stacking it on other warm gear, and owners report rooms heating up in summer and a stacked unit overheating. The relay volume knob's 1 dB clicks are widely liked, but one owner found fast turns can skip steps, a reviewer found menu navigation through the volume knob clumsy, and the 4.4 mm jack's recess can refuse thick aftermarket plugs.

“the main drawback is that the bliss is physically very large, and due to the high heat output, it’s suggested that you do not stack this with other hot components”

GoldenSound

“一是機器如原廠所說發熱確實比較明顯，因此使用時的散熱需要注意。”

hachima0202 · PTT Headphone (“as the maker says, it runs noticeably hot, so mind the ventilation”)

“The only drawback is that very fast volume changes can occasionally confuse the controller, resulting in incorrect step changes.”

Exekuhtor · Head-Fi

“I love my Bliss, but on 90 plus days, my room starts to get too hot.”

edwina77 · Head-Fi

Sources split, though unevenly. Every hands-on reviewer praises the thick aluminium casework, machined feet and component quality, and a sweep of the long-running Head-Fi owners' thread found no reported hardware failures. A small minority report unit-level problems: one US buyer received a dead unit and described a difficult warranty process, one early owner found finish blemishes, and one heard transformer hum.

Sources split. Most editorial reviewers call it a bargain at its tier — one bought it after reviewing it — because it pairs summit-level noise and power with a real preamp. Dissenters find it doesn't stack up against similarly priced rivals with more slam, or hear no gain over far cheaper amps. The price has also risen since launch, from $2,998 to $3,498 for the standard unit.