250Wpc Output, Robust Sound, THX Ultra2 Certification: Direct-Coupled Parasound A 31 Three-Channel Power Amplifier Has Beauty, Brains, and Brawn to Handle Music and Movies
Do your home-theater entertainment and two-channel music listening a major favor by allowing the Parasound A 31 three-channel power amplifier do the heavy lifting. Featuring John Curl-designed circuitry and high-bias Class A/AB operation, the direct-coupled A 31 possesses the brawn, beauty, and brains needed to drive the three most-important speakers in a multichannel configuration while taking a load off your receiver or pre/pro so the latter can ably fuel the rear channels. Or, use A 31 to drive your center and rear channels and a separate amp to power the mains. Smart – and easy!
Outputting 250Wpc into eight ohms, the THX Ultra2-certified A 31 leans on a massive 1.5kVA encapsulated toroidal transformer with independent secondary windings for each channel. A complementary MOSFET driver stage and JEFT input stage interface with 24 beta-matched 15A/60MHz bipolar output transistors. And let's not forget about A 31's 98,400uF of power supply filter capacitance. Or its DC servo and relay protection circuits, which accompany AC present, channel status, and high-temp indicators. Indeed, this versatile and hefty 65-pound unit is one honey of an amp.
A 31 also has you covered in terms of ease of use. Adjustable gain for up to 6dB over THX Reference level, auto turn-on via 12V trigger or audio signal, and supplied carry handles and a rack-mounting adapter all come standard. And you'll never sweat when hooking up your speakers. A 31's heavy-duty 24k gold-plated, five-way terminals handle all types of terminations.
Dynamic and detailed, transparent and focused, controlled and defined, A 31 bridges the gap between music and film needs. Ultra-low THD ratings (less the 0.2% at full power) and an incredible 112dV signal-to-noise ratio confirm its abilities. Parasound's hallmark build quality and five-year manufacturer warranty, along with our 100% Music Direct Satisfaction Guarantee, give you all the extra confidence and security you require.
"The Halo A 31 has a clear, detailed sound that belies its price, combined with just a touch of warmth. This blend of qualities made it a joy to listen to. Add to that its prodigious power output and rock-solid build quality, and I can assure you: It's the real deal."
– Roger Kanno, SoundStage! Access
"Immediately, I was struck by the Halo A 31's treble. Whether in two channels or more, it seemed to reveal more detail across the soundstage, and not only in terms of minor matters not noticed before. It also revealed subtleties of texture, such as the changes in harmonic structure that accompany changes in bow-on-string pressure, whether in solo passages or with massed strings."
– Kalman Rubinson, Stereophile
"The Halo A 31 is a wonderful amplifier. By staying out of the way and letting me enjoy the music, the A 31 made this review a challenge to find new ways to say that it sounded wonderful. The Halo A 31 is able to drive any speaker you are going to throw at it and not complain, as well as impeccably built and beautiful in appearance."
– Secrets of Home Theater and High Fidelity
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
> 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 (WHD): 17-1/2" x 7-5/8" x 20"
Weight: 65 lbs.
User Manual (PDF, 1.4 MB)