Does the Schiit Valhalla 2 drive the Koss Porta Pro?

Computed from measured specifications · target SPL 110 dB · load 50 Ω

Ample OTL-compatible pairing

The Schiit Valhalla 2 drives the Koss Porta Pro with ample headroom (~18.2 dB headroom at 50 ohms; needs ~2.8 mW, delivers 180 mW). This OTL tube amp suits the headphone's impedance (72 Ω) — a classically compatible pairing for high-output-impedance tube sources.

Headroom
18.2 dB
Required (110 dB SPL)
2.8 mW
Delivered (@ 50 Ω)
180 mW
Required voltage
0.45 Vrms

Power Headroom

Headroom: 18.2 dB 0 · target 18.2 dB below target marginal adequate ample -14 dB +10 +20 +36 dB

Scale shows dB headroom above the 2.8 mW required to reach 110 dB SPL. Amp delivers 180 mW at 50 Ω (+18.2 dB above target).

Koss Porta Pro Dynamic · on-ear
Impedance (rated) 60 Ω
Impedance (measured) Source: reference-audio-analyzer.pro/en/r… 72.15 Ω measured
Sensitivity (rated) 101.0 dB/mW
Sensitivity (measured) 105.6 dB/mW measured
Driver Dynamic
Spec basis Measured
Measured by Reference Audio Analyzer (https://reference-audio-analyzer.pro/en/report/hp/koss-porta-pro.php) · Source ↗
Schiit Valhalla 2 Desktop Tube · Single Ended
Output impedance manufacturer 14.0 Ω
Power @ 50 Ω 180 mW
Power @ 300 Ω 800 mW
Power @ 600 Ω 450 mW
Power source Manufacturer
Schiit Valhalla 2 manufacturer spec (Audiophonics retailer, citing Schiit official): 180/800/450 mW at 50/300/600 Ω. OTL/hybrid topology: more power into 300 Ω than 50 Ω (normal for OTL). Output impedance 14 Ω (hi-gain) / 3.5 Ω (lo-gain) from Schiit PDF manual and Schiit Europe. Using 14 Ω as worst-case for damping check. · Source ↗
Impedance compatibility

This OTL tube amp's high output impedance (14 Ω) is a good match for the Koss Porta Pro's 72 Ω impedance. The impedance ratio (5.2×) falls within the recommended range for high-output-impedance tube sources — a classically well-matched pairing.

Where to buy

Schiit Valhalla 2 on Amazon ↗ Koss Porta Pro 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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Little Dot MkII Ample 15.6 dB
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See all amplifiers for the Koss Porta Pro →

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AKG K240 Studio Adequate 3.6 dB
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See all headphones for the Schiit Valhalla 2 →