Dunu Vulkan 2: how much amplifier do you need?

The Dunu Vulkan 2 is 35Ω with a sensitivity of 113.0 dB/mW, which is 127.6 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 0.05 mW, or 42 mV across the drivers.

That puts it in the easy category. A phone, a laptop headphone jack or the cheapest USB dongle will drive it to painful levels. Of the 280 sources in the database, 280 have at least 10 dB of headroom and another 0 have enough. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.

The two numbers that decide everything

Impedance35 Ω
Sensitivity113.0 dB/mW
Sensitivity (voltage)127.6 dB/V
Power for 100 dB SPL0.05 mW
Voltage for 100 dB SPL42 mV
TypeIn-ear monitor
Easy to drive — anything will do it
All 280 sources at 100 dB SPL into 35Ω
Comfortable 280Enough 0Marginal 0Not enough 0
Cheapest portable source that does it
$9 · USB dongle · +27 dB headroom
Cheapest desktop amp with 10 dB to spare
$75 · desktop DAC/amp · +34 dB headroom

Sensitivity here is in dB per milliwatt. Why the unit matters.

Where this sensitivity figure comes from

Dunu publishes this directly as 113 dB/mW ((@1kHz) (DUNU also prints 128dB/Vrms (@1kHz))), per milliwatt, so nothing was converted.

Source: dunu-topsound.com. How this data was built.

What is printed there, and what it is worth

As it is labelledAs printedToleranceStandard
Frequency Response5Hz – 40kHznot printednot printed

Dunu prints 5Hz – 40kHz for the Dunu Vulkan 2, under the heading “Frequency Response”. Source: dunu-topsound.com.

No tolerance is printed with it, so “5Hz – 40kHz” says nothing about how loud this headphone actually is at 5 Hz.

Only what the maker printed; maker by maker.

Power, voltage and current by listening level

LevelWhat it isPowerVoltageCurrent
85 dB SPLquiet background listening0.00 mW7 mV0.2 mA
95 dB SPLnormal listening0.02 mW24 mV0.7 mA
100 dB SPLloud listening0.05 mW42 mV1.2 mA
105 dB SPLvery loud0.16 mW74 mV2.1 mA
110 dB SPLpeaks on dynamic music0.50 mW0.13 V3.8 mA

Most people listen between 75 and 85 dB; the 100 dB row leaves room for peaks.

The cheapest sources that drive them with room to spare

The 15 cheapest of the 280 sources here that reach 100 dB SPL into 35Ω with at least 10 dB of headroom and no known hiss or output-impedance problem with these headphones. All 280 sources, judged for these headphones.

SourceTypePricePower into 35ΩHeadroomVerdict
FiiO SnowSky Tiny AUSB dongle$2231 mW+28 dBComfortable
FiiO SnowSky Tiny BUSB dongle$2231 mW+28 dBComfortable
Tanchjim Stargate IIUSB dongle$4069 mW+31 dBComfortable
ddHiFi TC35ALUSB dongle$46192 mW+36 dBComfortable
ddHiFi TC35AirUSB dongle$46192 mW+36 dBComfortable
Fosi Audio N3Bluetooth receiver$50126 mW+34 dBComfortable
Hidizs SD2USB dongle$5064 mW+31 dBComfortable
iFi GO linkUSB dongle$5965 mW+31 dBComfortable
Kiwi Ears Allegro ProUSB dongle$6062 mW+31 dBComfortable
ddHiFi TC35Pro (Mountain2)USB dongle$6659 mW+31 dBComfortable
DUNU DTC 480USB dongle$7059 mW+31 dBComfortable
EPZ TP35 ProUSB dongle$70102 mW+33 dBComfortable
Aiyima A2 Prodesktop DAC/amp$75137 mW+34 dBComfortable
ddHiFi TC35Pro (Eye2)USB dongle$7659 mW+31 dBComfortable
ddHiFi TC44 Pro E2USB dongle$99229 mW+37 dBComfortable

The three ways a source goes wrong

Hiss. At 127.6 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Mjolnir 3, would put its hiss at roughly 36 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.

Output impedance. At 35Ω these want a source output impedance below 4.38Ω to satisfy the one-eighth rule; 35 of the 192 sources that publish one miss it. Check yours here.

Similar headphones

Compared with its stablemates: vs Alpha 3 · vs DN-142 · vs Glacier · vs Kima.

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