Campfire Audio Andromeda 2023: how much amplifier do you need?

The Campfire Audio Andromeda 2023 is 9Ω with a sensitivity of 94.0 dB/mW, which is 114.5 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 4.0 mW, or 0.19 V 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 53 sources in the database, 52 have comfortable headroom. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.

The two numbers that decide everything

Impedance9 Ω
Sensitivity94.0 dB/mW
Sensitivity (voltage)114.5 dB/V
TypeIn-ear monitor
BrandCampfire Audio
Easy to drive — anything will do it

Sensitivity here is in dB per milliwatt. Manufacturers often quote dB per volt instead and leave the unit off, which is the single most common reason online calculators give answers that are 10–15 dB wrong. The converter explains the difference.

Power, voltage and current by listening level

LevelWhat it isPowerVoltageCurrent
85 dB SPLquiet background listening0.13 mW34 mV3.7 mA
95 dB SPLnormal listening1.3 mW0.11 V11.8 mA
100 dB SPLloud listening4.0 mW0.19 V21.0 mA
105 dB SPLvery loud13 mW0.34 V37.4 mA
110 dB SPLpeaks on dynamic music40 mW0.60 V66.5 mA

Most people listen between 75 and 85 dB. The 100 dB row is the one worth planning around: it gives you headroom for dynamic peaks without designing your system for a volume that would damage your hearing in under fifteen minutes. The safe listening calculator puts numbers on that.

What drives them, from a $9 dongle upwards

Every source in the database, judged at 100 dB SPL into 9Ω. “Headroom” is how much power is left over above what the headphone needs — 10 dB means ten times the required power, which is what you want for dynamic peaks.

SourceTypePricePower into 9ΩHeadroomVerdict
Schiit Ragnarok 2desktop amplifier$15006.8 W+32 dBComfortable
Schiit Mjolnir 3desktop amplifier$8002.2 W+28 dBComfortable audible hiss
Burson Soloist 3X GTdesktop amplifier$15002.2 W+28 dBComfortable
Chord Hugo TT 2desktop amplifier$50002.2 W+28 dBComfortable
Schiit Asgard 3desktop amplifier$2502.0 W+27 dBComfortable
Ferrum OORdesktop amplifier$18002.0 W+27 dBComfortable
Topping A90 Discretedesktop amplifier$4001.7 W+26 dBComfortable
Wells Audio Milodesktop amplifier$25001.7 W+26 dBComfortable
Topping A90desktop amplifier$5001.5 W+26 dBComfortable
Headamp GS-X Minidesktop amplifier$14001.4 W+25 dBComfortable
JDS Labs Element III MK2desktop DAC/amp$3501.3 W+25 dBComfortable
SMSL HO200desktop amplifier$3001.1 W+25 dBComfortable
iFi iCAN Prodesktop amplifier$6001.1 W+25 dBComfortable audible hiss
Topping L30 IIdesktop amplifier$130984 mW+24 dBComfortable
Cayin HA-6Adesktop amplifier$1800844 mW+23 dBComfortable audible hiss, damping
FiiO M17portable player$1800844 mW+23 dBComfortable faint hiss
Schiit Magni+desktop amplifier$109562 mW+21 dBComfortable
Fiio K7desktop DAC/amp$180562 mW+21 dBComfortable
Fiio K9 Prodesktop DAC/amp$380562 mW+21 dBComfortable
Geshelli Archel Prodesktop amplifier$200506 mW+21 dBComfortable
Schiit Magni Heresydesktop amplifier$100450 mW+21 dBComfortable
SMSL SH-9desktop amplifier$150422 mW+20 dBComfortable
JDS Labs Atom+ (2nd gen)desktop amplifier$100281 mW+18 dBComfortable
iFi Zen CANdesktop amplifier$200281 mW+18 dBComfortable
HiBy R6 Pro IIportable player$750211 mW+17 dBComfortable faint hiss
FiiO M11Sportable player$500188 mW+17 dBComfortable faint hiss
FiiO KA17USB dongle$150183 mW+17 dBComfortable faint hiss
FiiO BTR17Bluetooth receiver$200183 mW+17 dBComfortable faint hiss
Astell&Kern SP3000portable player$3700169 mW+16 dBComfortable faint hiss
FiiO KA13USB dongle$80155 mW+16 dBComfortable faint hiss
Qudelix T71Bluetooth receiver$200112 mW+14 dBComfortable faint hiss
Astell&Kern SR35portable player$800112 mW+14 dBComfortable faint hiss
FiiO BTR15Bluetooth receiver$11096 mW+14 dBComfortable faint hiss
FiiO BTR7Bluetooth receiver$20090 mW+14 dBComfortable faint hiss
Questyle M15USB dongle$25084 mW+13 dBComfortable faint hiss
Hidizs S9 ProUSB dongle$7576 mW+13 dBComfortable faint hiss
Sony NW-WM1AM2portable player$140070 mW+12 dBComfortable faint hiss
Qudelix 5KBluetooth receiver$11068 mW+12 dBComfortable faint hiss
Moondrop Dawn ProUSB dongle$6065 mW+12 dBComfortable faint hiss
iBasso DC04 ProUSB dongle$9065 mW+12 dBComfortable faint hiss
Shanling UP5Bluetooth receiver$13065 mW+12 dBComfortable faint hiss
Truthear SHIOUSB dongle$7060 mW+12 dBComfortable faint hiss
Schiit Vali 2+desktop amplifier$20056 mW+12 dBComfortable audible hiss, damping
FiiO KA11USB dongle$3056 mW+12 dBComfortable faint hiss
ddHiFi TC44 ProUSB dongle$11053 mW+11 dBComfortable faint hiss
Shanling UA5Bluetooth receiver$22051 mW+11 dBComfortable faint hiss
Tempotec Sonata BHD ProUSB dongle$4037 mW+10 dBEnough faint hiss
iBasso DC03 ProUSB dongle$6034 mW+9 dBEnough faint hiss
Generic CX31993 donglesUSB dongle$1217 mW+6 dBEnough audible hiss, damping
EarStudio ES100 MK2Bluetooth receiver$9017 mW+6 dBEnough faint hiss
Sony NW-A306portable player$35014 mW+5 dBEnough faint hiss, damping
Apple USB-C dongle (US)USB dongle$98.4 mW+3 dBEnough audible hiss
Apple USB-C dongle (EU)USB dongle$94.2 mW+0 dBMarginal audible hiss

The three ways a source goes wrong

Hiss. At 114.5 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Vali 2+, would put its hiss at roughly 22 dB SPL in these headphones — clearly audible in quiet passages. The hiss calculator lets you check your own amplifier's noise figure.

Output impedance. At 9Ω these want a source output impedance below 1.12Ω to satisfy the one-eighth rule. 4 of the 53 sources here miss it, the worst being the Schiit Vali 2+ at 6Ω. Above that threshold the source starts shaping the frequency response. Check yours here.

Similar headphones

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