Gustard H26: power output and what it will drive

The Gustard H26 is a desktop amplifier at $1099. It delivers 9.7 W into 32Ω and 1.0 W into 300Ω, which ranks it 3 of 280 for raw power among the sources in this database.

Measured at 100 dB SPL it has comfortable headroom on 566 of the 567 dynamic and planar headphones catalogued here and enough but not generous on 1. High-end balanced amp. The manual publishes one figure at one load and plots the rest as curves, so most of this table is derived.

The shop listings these figures stand on quote 9.7 W into 32Ω. Everything else in the table above is worked out from those figures, and this table says which is which.

The published figures describe the balanced output. A single-ended jack on the same unit will put out less — usually about half the voltage and a quarter of the power.

Derivation holds output voltage steady between and beyond the published loads rather than output power, because that is what an amplifier actually does. The full method is written up here.

One caveat about the source. None of the addresses below is a Gustard document. The figures here stand on ManualsLib, a manual aggregator and Apos Audio, a retailer, which are transcriptions of the factory table rather than the table itself. A transcription is usually faithful and may well be exact here — but it can carry an old revision, and nothing on this site would notice if it did. Find these numbers on Gustard's own site and send the link; this paragraph comes off.

Source: manualslib.com, apos.audio.

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 0.1Ω output impedance this source satisfies the one-eighth rule with every headphone in the database, down to the 3Ω in-ears. Nothing here will have its frequency response shaped by the source.

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, 22 do everything the Gustard H26 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 $1099 — $1000 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 Aune S17 Pro EVO · vs Schiit Mjolnir 3 · vs Singxer SA-1 · 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 Gustard source in the database, and how much of what this site says about them came from Gustard’s own documents.