Alpha 3 vs Kima: which needs more amplifier?

The Dunu Alpha 3 is 32Ω at 105.0 dB (no reference unit printed); the Dunu Kima is 32Ω at 108.0 dB (no reference unit printed). This page is only about what they ask of an amplifier — not how they sound, which no specification on either sheet can tell you.

The Alpha 3 needs 3.0 dB more than the Kima to reach the same loudness — 0.32 mW against 0.16 mW.

The numbers that decide it

SpecificationAlpha 3Kima
Impedance32 Ω32 Ω
Sensitivity105.0 dB108.0 dB
Sensitivity (voltage)119.9 dB/V122.9 dB/V
Power for 100 dB0.32 mW0.16 mW
Voltage for 100 dB0.10 V71 mV
Current for 100 dB3.1 mA2.2 mA
Highest source impedance
that leaves them alone (one-eighth rule)
4.00 Ω4.00 Ω
Sources that reach 100 dB
out of 280
280280

One caution before reading the rows. Dunu Alpha 3 and Dunu Kima printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, each of them needs far more than the table says. Why the two readings differ by so much.

Where the two part company

Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.

3 sources stay below the audible-hiss threshold with the Alpha 3 but cross it with the Kima (FiiO BTR11, FiiO K11 R2R, Rupert Neve RNHP).

280 of the 280 sources here reach 100 dB on both. That count is about power only — the output-impedance and hiss lines above are separate questions, and a source can pass this one and fail those.

What each one needs from 80 to 105 dB

The gap between these two in decibels does not change with volume — it is a property of the two headphones. What changes is the size of the numbers, and it changes fast: every 10 dB costs ten times the power. The row that matters is the one nearest the level you listen at, and for most people that is nearer the top of this table than the bottom.

The Alpha 3 is more demanding than 34% of the 567 non-electrostatic models in this database; the Kima than 23%. Both figures use the same measure as the rest of the site: whichever runs out first against a 2 V, 100 mW dongle, voltage or power.

dB SPLAlpha 3 powerAlpha 3 voltageKima powerKima voltage
803.2 µW10 mV1.6 µW7 mV
850.01 mW18 mV5.0 µW13 mV
900.03 mW32 mV0.02 mW23 mV
950.10 mW57 mV0.05 mW40 mV
1000.32 mW0.10 V0.16 mW71 mV
1051.0 mW0.18 V0.50 mW0.13 V

105 dB is included because forum power figures are usually quoted there or higher. It is also a level that damages hearing in minutes — how many minutes is its own calculator.

The cheapest source that satisfies both

SourcePriceHeadroom, Alpha 3Headroom, KimaOutput impedanceNoise
JadeAudio JA11$2019.8 dB22.8 dB0.5 Ω1.7 µV
FiiO KA11$2928.0 dB31.0 dB0.7 Ω1.7 µV
FiiO BTR13$5925.0 dB28.0 dB0.6 Ω1.0 µV

Of the 280 sources here, 280 reach 100 dB on both. That is the easy axis. 66 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both — the rest either fail one of those or never printed the number at all, and 208 of them are in the second group.

The cheapest of the 66 is the JadeAudio JA11, at $20. It leaves 19.8 dB of headroom on the Alpha 3 and 22.8 dB on the Kima, its output impedance is 0.5 Ω against a one-eighth limit of 4.00 Ω for both, and its noise figure puts the hiss floor 15 dB and 12 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.

Cheapest that satisfies three published numbers is not the same as best, and none of it is about how either headphone sounds. To put either model against a source this page does not mention, or to change the target loudness, use the amplifier matcher.

What each sheet prints, and what it is worth

ModelAs printedToleranceStandard
Alpha 35Hz-40kHznot printednot printed
Kima5Hz-40kHznot printednot printed

Dunu prints the same thing for both the Alpha 3 and the Kima: 5Hz-40kHz.

Kima: Printed in the "Technical Info" block; DUNU gives the row no label of its own beyond that heading.

Neither range has a tolerance printed beside it, and that is the whole of what this section can tell you. The two sheets print the same range, which is itself a hint about how much the number is worth. A ±dB figure is what turns a range into a specification, and of the 490 models whose maker prints a range, 58 print it.

None of this is a measurement. What each maker publishes, and what it is worth, is set out in the frequency response audit.

Both pages in full

Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Dunu Alpha 3 and Dunu Kima. Each figure on this page is labelled on those pages with where it came from, including the ones Dunu never published — what that maker publishes, counted.

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