Hola vs PURE: which needs more amplifier?

The Truthear Hola is 28Ω at 104.5 dB/mW; the Truthear PURE is 13.8Ω at 105.4 dB/mW. 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 Hola needs 0.9 dB more than the PURE to reach the same loudness — 0.35 mW against 0.29 mW.

The numbers that decide it

SpecificationHolaPURE
Impedance28 Ω13.8 Ω
Sensitivity104.5 dB/mW105.4 dB/mW
Sensitivity (voltage)120.0 dB/V124.0 dB/V
Power for 100 dB0.35 mW0.29 mW
Voltage for 100 dB100 mV63 mV
Current for 100 dB3.6 mA4.6 mA
Highest source impedance
that leaves them alone (one-eighth rule)
3.50 Ω1.73 Ω
Sources that reach 100 dB
out of 280
280280

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.

4 sources are low enough in output impedance for the Hola under the one-eighth rule but not for the PURE (Schiit Vali 2+, Astell&Kern HC3, RME Fireface UFX II, 1 more).

5 sources stay below the audible-hiss threshold with the Hola but cross it with the PURE (FiiO BTR11, FiiO K11 R2R, Schiit Valhalla 3, 2 more).

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 Hola is more demanding than 31% of the 567 non-electrostatic models in this database; the PURE than 18%. 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 SPLHola powerHola voltagePURE powerPURE voltage
803.5 µW10 mV2.9 µW6 mV
850.01 mW18 mV9.1 µW11 mV
900.04 mW32 mV0.03 mW20 mV
950.11 mW56 mV0.09 mW35 mV
1000.35 mW100 mV0.29 mW63 mV
1051.1 mW0.18 V0.91 mW0.11 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, HolaHeadroom, PUREOutput impedanceNoise
JadeAudio JA11$2018.7 dB16.5 dB0.5 Ω1.7 µV
FiiO KA11$2927.6 dB28.6 dB0.7 Ω1.7 µV
FiiO BTR13$5924.6 dB25.5 dB0.6 Ω1.0 µV

Of the 280 sources here, 280 reach 100 dB on both. That is the easy axis. 65 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 65 is the JadeAudio JA11, at $20. It leaves 18.7 dB of headroom on the Hola and 16.5 dB on the PURE, its output impedance is 0.5 Ω against a one-eighth limit of 3.50 Ω and 1.73 Ω, and its noise figure puts the hiss floor 15 dB and 11 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
Hola8-46kHz (IEC61094, Free Field)not printedIEC61094 (free field)
 20-20kHz (IEC60318-4, -3dB)-3 dBIEC60318-4
PURE7-40kHz (IEC61094, Free Field)not printedIEC61094 (free field)
 20-20kHz (IEC60318-4, -3dB)-3 dBIEC60318-4

Truthear prints two ranges, “8-46kHz (IEC61094, Free Field)” and “20-20kHz (IEC60318-4, -3dB)”, for the Hola and two ranges, “7-40kHz (IEC61094, Free Field)” and “20-20kHz (IEC60318-4, -3dB)”, for the PURE.

Both sheets print a tolerance, which is rare enough to be worth pointing at: only 58 of the 490 models with a printed range do. These two ranges can be set against each other, because each of them says how far down the response is allowed to be at the ends.

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: Truthear Hola and Truthear PURE. Every figure on this page comes from what Truthear published, or is derived from it — what that maker publishes, counted.

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