Parasound Halo A31 Amplifier

Power You Can Feel

Drop the A31 into your system and everything locks in: voices stand center‑stage, low end digs deeper without bloat, and effects surge with head‑turning impact. It’s the missing muscle your movies and music have been asking for.

Designed by legendary audio engineer John Curl, it runs high‑bias Class A/AB (the first ~7 watts in pure Class A) with a direct‑coupled signal path for maximum clarity. A 1.5 kVA toroidal transformer and 98,400 µF of filter capacitance supply clean current on demand, while 250 W x3 into 8 Ω (400 W x3 into 4 Ω), balanced XLR and RCA inputs, and THX Ultra2 certification make integration straightforward in serious home theaters. 

Praised by audiophiles and reviewers alike:

• “Clear, detailed sound that belies its price…a joy to listen to.” — SoundStage! Access (Reviewers’ Choice)
• “Impeccable in fit and finish…powerful but refined.” — Secrets of Home Theater & High Fidelity 

Awards & Recognition

• Stereophile — Recommended Components (2012, Surround‑Sound Components). 
• SoundStage! Access — Reviewers’ Choice (2015).
• Secrets of Home Theater & High Fidelity — Best of 2012: Best Multichannel Amplifier.

Specifications: 

Continuous power output:
250 watts RMS x 3, 20 Hz - 20 kHz, 8 Ω, all channels driven
400 watts RMS x 3, 20 Hz - 20 kHz, 4 Ω, all channels driven

Current capacity:
60 amperes peak per channel

Power bandwidth:
5 Hz - 100 kHz, +0/-3 dB at 1 watt

Total harmonic distortion:
< 0.2 % at full power

IM distortion: balanced 16 V rms
< 0.04 %

Slew rate:
> 130 V/µsecond

Dynamic headroom:
> 1.5 dB

Interchannel crosstalk:
> 78 dB at 1 kHz;
> 63 dB at 20 kHz

Input sensitivity:
1 V for 28.28 V (THX Reference)

Input impedance:
47 k Ω unbalanced; 94 k Ω balanced

S/N ratio:
112 dB, input shorted, IHF A-weighted

Damping factor:
> 1100 at 20 Hz

Dimensions:
17-1/2" w x 7-5/8" h x 20" d, 7" h without feet

Net weight: 65 lb.

Shipping weight: 79 lb.