Does the Drop THX AAA 789 drive the Sennheiser HD 660S?

Computed from measured specifications · target SPL 110 dB · load 300 Ω

Ample

The Drop THX AAA 789 drives the Sennheiser HD 660S with ample headroom (~16.5 dB headroom at 300 ohms; needs ~4.5 mW, delivers 200 mW).

Headroom
16.5 dB
Required (110 dB SPL)
4.5 mW
Delivered (@ 300 Ω)
200 mW
Required voltage
0.99 Vrms

Power Headroom

Headroom: 16.5 dB 0 · target 16.5 dB below target marginal adequate ample -14 dB +10 +20 +36 dB

Scale shows dB headroom above the 4.5 mW required to reach 110 dB SPL. Amp delivers 200 mW at 300 Ω (+16.5 dB above target).

Sennheiser HD 660S Dynamic · over-ear
Impedance (rated) 150 Ω
Impedance (measured) Source: reference-audio-analyzer.pro/en/r… 216.75 Ω measured
Sensitivity (rated) 104.0 dB/mW
Sensitivity (measured) 103.45 dB/mW measured
Driver Dynamic
Spec basis Measured
Measured by Reference Audio Analyzer (https://reference-audio-analyzer.pro/en/report/hp/sennheiser-hd-660s.php) · Source ↗
Drop THX AAA 789 Desktop Ss · Single Ended
Output impedance manufacturer 0.1 Ω
Power @ 16 Ω 3000 mW
Power @ 32 Ω 1800 mW
Power @ 300 Ω 200 mW
Power @ 600 Ω 100 mW
Power source Manufacturer
Drop product page SE figures: 3000/1800/200/100 mW at 16/32/300/600 Ω. THX AAA topology, output impedance <0.1 Ω (class spec). · Source ↗

Where to buy

Drop THX AAA 789 on Amazon ↗ Sennheiser HD 660S on Amazon ↗

Disclosure: links above are Amazon affiliate links. As an Amazon Associate this site earns from qualifying purchases — at no extra cost to you. Affiliate commissions do not influence verdicts; all analysis is computed independently from the data.

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