Does the FiiO K7 drive the HiFiMan Sundara?

Computed from measured specifications · target SPL 110 dB · load 32 Ω

Verdict

Ample

The FiiO K7 drives the HiFiMan Sundara with ample headroom (~13.5 dB headroom at 32 ohms; needs ~54.3 mW, delivers 1220 mW).

Headroom
13.5 dB
Required (110 dB SPL)
54.3 mW
Delivered (@ 32 Ω)
1220 mW
Required voltage
1.46 Vrms

Power Headroom

Headroom: 13.5 dB 0 · target 13.5 dB below target marginal adequate ample -14 dB +10 +20 +36 dB

Scale shows dB headroom above the 54.3 mW required to reach 110 dB SPL. Amp delivers 1220 mW at 32 Ω (+13.5 dB above target).

HiFiMan Sundara Planar · over-ear
Impedance (rated) 37 Ω
Impedance (measured) Source: reference-audio-analyzer.pro/en/r… 39.25 Ω measured
Sensitivity (rated) 94.0 dB/mW
Sensitivity (measured) 92.65 dB/mW measured
Driver Planar
Spec basis Measured
Measured by Reference Audio Analyzer (https://reference-audio-analyzer.pro/en/report/hp/hifiman-sundara.php) · Source ↗
FiiO K7 Dac Amp · Single Ended
Output impedance manufacturer 1.0 Ω
Power @ 32 Ω 1220 mW
Power @ 300 Ω 140 mW
Power @ 600 Ω 70 mW *est.
Power source Manufacturer
* Loads marked "est." are derived from the published voltage ceiling at a lower-impedance load (V = √(P·R) → P_higher = V²/R_higher). All derivations are upward only.
FiiO K7 SE headphone output from manufacturer spec page (fiio.com/k7_parameters): L+R ≥ 1220 mW+1220 mW @ 32 Ω, L+R ≥ 140 mW+140 mW @ 300 Ω (THD+N<1%). Output impedance <1 Ω @ 32 Ω from manufacturer. 600 Ω derived from 300 Ω. · Source ↗
Planar driver note

Planar-magnetic headphones can have high current demands that are not fully captured by the power headroom model. Even with adequate headroom, some solid-state amps may struggle to deliver sufficient peak current for transient dynamics. Prefer amps rated for low-impedance planars.

Where to buy

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Drop THX AAA 789 Ample 15.2 dB
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Little Dot MkII Marginal 2.7 dB
Apple USB-C to 3.5mm Insufficient -2.4 dB
HeadphoneHeadroom
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