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Pass Labs

HPA-1c

The 'c' revision adds local regulation to the servo circuit and an upgraded power supply, which Pass Labs says cut noise by about 10 dB.

Type
Solid-state headphone amplifier
Output
3.5 W into 20 ohms
Weight
6.4 kg
List
$4,045

Output into any load

The line is what the HPA-1c delivers, estimated from its published ratings. Each square is a headphone in the catalog at the power it needs for a loud 110 dB peak.

Grado Signature HP100 SE: needs 0.20 mW at 38 ohmsFocal Stellia: needs 2.51 mW at 35 ohmsAudeze MM-520: needs 6.31 mW at 18 ohmsFocal Clear MG: needs 3.98 mW at 55 ohmsFostex TH900mk2: needs 10.0 mW at 25 ohmsMeze Audio Elite: needs 7.94 mW at 32 ohmsFocal Utopia (2022): needs 3.98 mW at 80 ohmsRosson Audio Design RAD-0: needs 15.8 mW at 29 ohmsYamaha YH-5000SE: needs 15.8 mW at 34 ohmsSony MDR-Z1R: needs 10.0 mW at 64 ohmsHIFIMAN HE1000se: needs 25.1 mW at 35 ohmsFinal D8000 Pro Edition: needs 15.8 mW at 60 ohmsZMF Caldera: needs 31.6 mW at 60 ohmsDan Clark Audio Stealth: needs 100 mW at 23 ohmsDan Clark Audio Expanse: needs 100 mW at 26 ohmsMeze Audio Empyrean II: needs 100 mW at 32 ohmsAudeze LCD-5s: needs 100 mW at 35 ohmsMeze Audio ARTA: needs 15.8 mW at 225 ohmsZMF Vérité Closed: needs 12.6 mW at 300 ohmsAudio-Technica ATH-ADX5000: needs 10.0 mW at 420 ohmsSennheiser HD 820: needs 16.6 mW at 300 ohmsSennheiser HD 800 S: needs 20.9 mW at 300 ohmsAbyss Diana TC Signature: needs 100 mW at 72 ohmsAbyss AB-1266 Phi TC: needs 158 mW at 50 ohmsHIFIMAN Susvara: needs 501 mW at 60 ohmsPublished: 3.5 W into 20 ohmsPublished: 200 mW into 300 ohms
Output into each loadPublished ratingHeadphone it drives at 110 dB (25)Needs more (0)Load in ohms across, power up, both on log scales

Build a setup with it

Start with the Dan Clark Audio Stealth, the hardest headphone here it drives with power in reserve.

Open in the setup builder →

Where to buy

$4,045

Price: silver; black is $4,545 at Moon Audio.

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Title block

Maker
Pass Labs
Model
HPA-1c
Type
Solid-state headphone amplifier
Made in
USA
Output impedance
2 ohms
Weight
6.4 kg
List price
$4,045 USD
Output power
3.5 W into 20 ohms; 200 mW into 300 ohms
Topology
Class A, low feedback, wide bandwidth; discrete JFET input stage and direct-coupled MOSFET output stage; single-ended 6.35 mm output; also works as a line preamp
Finish
Brushed aluminium chassis, black or silver (per Moon Audio)

What it drives

How the matching works

Plenty in reserve

10 dB or more above loud 110 dB peaks.

22

Other solid-state amplifiers

Sources