Five Channel Power Amplifier

Not available for online sale. Please contact us or send us a trade-in form if you are interested in purchasing this product.

If you have a trade-in, request Trade-in Price.


“I expected the A51 to sound good. What I wasn’t prepared for was how good it sounded right out of the box. Its midrange was totally seductive, its soundstage and imaging capabilities in the same league as some of the best gear I’ve ever heard at any price.” — Barry Willis, Stereophile Guide to Home Theater, “Recommended Components,” March/April, 2004

Raw Power Meets Elegant Circuit Design

“Harmonic Rightness”

Barry Willis praises the Parasound A51 for its “harmonic rightness” in Stereophile Guide to Home Theater for October 2003. “Its midrange was totally seductive, its soundstaging and imaging abilities in the same league as some of the best gear I’ve ever heard at any price… With music, the A51 radiated sweetness and light. With action films, it rained thunder and lightning. There aren’t many amplifiers that can so effortlessly cover both ends of the sonic spectrum.”

The Jan / Feb. 2004 Top Choice Awards issue of DVD ETC. magazine praises the Halo A51 multichannel amp and the Halo C2 surround sound processor for their “sonic performance, auto calibration, complete feature set, programmability and upgradeability.”

Uncompromising Audiophile Performance

Parasound’s five-channel Halo A51 power amplifier combines raw power with elegant circuit design. Designed by legendary audio guru John Curl in collaboration with CTC Builders, the Halo brings uncompromising audiophile performance to home theater.

THX Ultra 2 certification ensures movie-house quality sonics, but the Halo surpasses this critical benchmark by delivering Parasound-quality sound derived from the ultra-high-end Parasound JC-1 400-watt mono amp. Matched JFET inputs, MOSFET drivers, and high-current bipolar outputs contribute to its exceptional performance.

Class A / AB Operation and Impressive Firepower

The A51 boasts balanced inputs with discrete circuits and XLR connectors. Beautifully implemented high-bias Class A / AB operation makes the most of an impressive 250-watt-per-channel power output at 8 ohms and 400-watts-per-channel at 4 ohms. The 2.2 kVA encapsulated toroidal power transformer with independent secondary windings for each channel and 164,000 µF power supply filter capacitance delivers an impressive current capacity of 60 amps per channel. The direct-coupled design uses no capacitors or inductors in signal path. The complementary MOSFET driver stage relies on the firepower of 40 beta-matched 15 amp, 60 MHz bipolar output transistors and works in combination with a JFET input stage.

“Instant” Warm-up Feature

Like all the other amps in the Halo product series, the A51 has Parasound’s exclusive bias circuit, which permits the amplifier to sound perfect from the instant it’s turned on, rather than having to wait for bias to gradually build up as the amp warms up over time. Very high bias allows greater Class operating range than others. Even Halo’s implementation of its automatic turn-on feature is exceptional. Special relays bypass the AC “soft start” circuitry after it’s done its job for the purest AC and the purest sound.

And That’s Not All…

AC present, channel status, and high temperature indicators team up with DC Servo and relay protection circuits to keep this powerhouse running safely at peak performance for years of reliable service. Auto turn-on by 12-volt trigger or audio signal simplifies home theater and multi-room operation. Other features include heavy-duty 24k gold-plated 5-way speaker terminals, gold-plated RCA input jacks, and a rear-panel ground lift switch.


Owner’s Manual (1mb PDF)

*Parasound’s Limited Warranty: 5 years on parts and five years on labor.




As the nationally recognized leader in the field of high-end audio, home theater and home electronics, Overture is proud to offer Parasound’s line of high-performance music components including the new Halo JC 1+ that is the ultimate achievement of Parasound legendary designer John Curl. In the complicated landscape of audio, many companies put stratospheric price tags on great performance. Parasound’s mission couldn’t be more different. Simply put, they offer the most performance for the money by finding the sweetest spot between price and diminishing returns. Everything they do at Parasound is customer-centric because that’s how they define value. When they develop a new product they take the carpenter’s adage “measure twice, cut once” to the extreme. Each new model is tested, improved and re-tested under worst-case conditions. It comes to market only when it is a finished product that’s ready to stand the test of time. In fact, they don’t really know how long their amplifiers last because people write to thank them because the Parasound amp they purchased in the mid-’80s still works perfectly 30 years later. When you choose Parasound you’re getting uncompromised quality for every model. They all use the best parts and each must pass their strictest quality assurance. They wouldn’t have it any other way. If you are interested in purchasing any Parasound products, such as the new Parasound Halo JC1+, A20+, A23+, P6, HINT6, JC5, or JC3+, you can trade-in another electronic component on it by filling out our Trade-In Form.