Aune S17 Pro EVO: power output and what it will drive

The Aune S17 Pro EVO is a desktop amplifier at $799. It delivers 2.0 W into 32Ω and 235 mW into 300Ω, which ranks it 41 of 280 for raw power among the sources in this database.

Measured at 100 dB SPL it has comfortable headroom on 564 of the 567 dynamic and planar headphones catalogued here, enough but not generous on 2 and only marginal on 1. Power is published at 32Ω, 100Ω, 150Ω, 200Ω, 250Ω, 300Ω, 470Ω, 600Ω; the rest of the table is derived from those figures. Output noise is not published, so the hiss estimate cannot be run.

The manufacturer publishes 2.0 W into 32Ω, 688 mW into 100Ω, 464 mW into 150Ω, 348 mW into 200Ω, 282 mW into 250Ω, 235 mW into 300Ω, 150 mW into 470Ω, 117 mW into 600Ω. Everything else in the table above is worked out from those figures, and this table says which is which.

The balanced output is rated separately: 7.5 W into 32Ω through the XLR4 and 4.4mm jack.

Nothing here is derived: every figure in the table is either a number the maker published at that exact load or a number marked unverified. The method behind the labels is written up here.

Source: en.auneaudio.com, mall.auneaudio.com.

Ordered from easiest to hardest to drive. Headroom is measured at 100 dB SPL, which is louder than almost anyone listens — a small negative number means the source still plays loud, just without reserve for peaks.

These figures come from each manufacturer's own sensitivity rating. A handful of planars — the HiFiMAN Susvara and the Abyss AB-1266 in particular — are widely reported to need far more than their published sensitivity implies, so treat a bare pass on those as optimistic rather than settled.

The manufacturer does not publish an output noise figure for this source, so the hiss estimate that runs on every other page here cannot be run on this one. Rather than substitute a plausible number, this page leaves the question open.

If you know the noise figure from a measurement you trust, the hiss calculator takes it directly and tells you where that noise lands in your own in-ears.

At 1Ω output impedance, the one-eighth rule says this source suits headphones of 8.0Ω and above. 15 of the 567 models here fall below that. Most of them are multi-driver in-ears, and the mismatch tilts the frequency response audibly rather than subtly.

The rule is a rule of thumb, not physics: a source impedance below one eighth of the headphone's keeps the interaction under about 1 dB. The checker works it out for any pair.

Of the 280 sources here, 33 do everything the Aune S17 Pro EVO does as a headphone output: reach 100 dB on every headphone it reaches and stay inside the one-eighth rule wherever it does. The cheapest of them is the Schiit Magni Heresy at $99, against this one’s $799 — $700 less.

This counts a headphone output and nothing else. Inputs, converters, microphone preamps, balanced outputs, the volume control, the case and the warranty are all outside it, and any of them can be the reason to buy the dearer box. What the count does say is that the three numbers a maker can be held to do not separate them.

Worked out in advance against its closest rivals: vs Grace Design m900 · vs Gustard H26 · vs Rupert Neve RNHP · vs Schiit Lyr 5 · vs Singxer SA-1 · vs SMSL VMV P2 MK2 · vs Woo Audio WA6. Each of those pages lists the headphones that tell the two apart.

Or put any two side by side in the source comparison tool, or run your own headphones through the amplifier matcher. Or see every Aune source in the database, and how much of what this site says about them came from Aune’s own documents.