Stereophile – August 2019

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AESTHETIX AUDIO MIMAS

measurements, continued

(24/192 WAV, SFS Me-

dia SFS0070). We then

chose “Your Heart Is as

Black as Night,” from

Melody Gardot’s My

One and Only Thrill (CD,

Verve B0012563-02), and

ended with “John Taylor’s Month Away.”

After that, I listened to the same tracks again to grok the

sound of the Mimas functioning solely as a preamp, with the

Progressions handling amplification, and then compared this

As Schubert’s music tugged at my

heart, I noted the lovely liquid

ringing of the piano’s high notes

and the beauty of the sound overall.

instruments vibrating in space.
The difference lay in the slight
gauze thrown over the sound-
stage. Even with the system
fully settled in, I was never able
to close my eyes and say, “Yes,
I feel as though I’m listening to
this music in the actual record-
ing venue.” It always felt one
step removed.
Ten days later, when Peter
visited, we began with my old
standby: Iván Fischer and the
Budapest Festival Orchestra’s
recording of Mahler’s Sym-
phony 3 (DSD128, Channel
Classics CCSA 38817/Na-
tiveDSD). The beginning of
the first movement has blaring
horns, pounding percussion,
tinkly triangles, and silken
strings, all of which soon tran-
sition from militant cries of
alarm to the sweet sounds of spring. We also listened to
the first of Berg’s Three Pieces for Orchestra, “Praeludium,” in
Michael Tilson Thomas and the San Francisco Symphony’s
highly detailed, low-range–rich, wallop-packing recording

as offering 150Wpc into 8 ohms

(21.76dBW) and says it will typically

deliver 185W (22.67dBW). With both

channels driven and with clipping

defined as when the THD+noise in the

output reaches 1%, I measured the

clipping power into 8 ohms as 180Wpc

(22.55dBW, fig.4). Aesthetix speci-

fies the maximum power into 4 ohms

as “nearly double” that into 8 ohms;

I measured 275Wpc into 4 ohms

(21.4dBW, fig.5).

I also examined how the THD+N

percentage varied with frequency at a

fairly high level, 20V, which is equiva-

lent to 50W into 8 ohms and 100W

into 4 ohms. The THD+N was low into

8 ohms (fig.6, blue and red traces), but

higher into 4 ohms (cyan, magenta).

The usual rise in the treble due to the

reduction in the circuit’s open-loop

gain at high frequencies was absent.

The right channel’s THD+N wave-

form at this level (fig.7) indicates that

the distortion is predominantly third-

harmonic in nature, though spectral

analysis (fig.8) reveals that there are

also higher harmonics present, and

there was a much higher level of sec-

ond harmonic in the left channel (blue

trace) than the right (red). Tested

with an equal mix of 19 and 20kHz

tones a few dB below clipping into 4

ohms, the Aesthetix produced fairly

low levels of high-order intermodula-

tion distortion (fig.9). However, while

the difference product at 1kHz lay at

a very low –106dB (0.0006%) in the

right channel, it was much higher in

the left channel (blue trace), at –84dB

(0.006%). This is still low in absolute

terms, however.

Its measured performance indi-

cates that Aesthetix Audio’s Mimas

integrated amplifier is generally well

engineered, though its noise floor at

high settings of the volume control is

higher than it need be. However, as

the high gain will mean keeping the

volume control low, this will not be a

factor in the amplifier’s sound qual-

ity.—John Atkinson

Fig.7 Aesthetix Mimas, right channel, 1kHz wave-

form at 50W into 8 ohms, 0.069% THD+N (top);

distortion and noise waveform with fundamental

notched out (bottom, not to scale).

Fig.8 Aesthetix Mimas, spectrum of 50Hz

sinewave, DC–1kHz, at 50W into 8 ohms (left

channel blue, right red; linear frequency scale).

Fig.9 Aesthetix Mimas, HF intermodulation spec-

trum, DC–30kHz, 19+20kHz at 100W peak into 4

ohms (left channel blue, right red; linear frequency

scale).

Hz Hz

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