Parasound HALO A21+ Power Amp

Parasound HALO A21+ Power Amplifier

Experience reference-grade clarity and effortless power with the Parasound HALO A21+, engineered for audiophiles who demand precision and control.

The Parasound HALO A21+ is a high-current, two-channel power amplifier delivering 300 watts per channel into 8 ohms and 500 watts per channel into 4 ohms. Designed by legendary engineer John Curl, it features a high-bias Class A/AB topology for pure, detailed sound and dynamic musicality.

With a massive 1.3 kVA toroidal transformer and 108,000 µF of filter capacitance, the Parasound HALO A21+ maintains composure even under the most demanding loads. It delivers extraordinary current capability and is stable down to 2 ohms, ensuring full control of even the most challenging loudspeakers.

The dual-mono construction with separate power supplies for each channel produces exceptional channel separation and low distortion. Balanced XLR and unbalanced RCA inputs, loop-output, and 12 V trigger control make the Parasound HALO A21+ ideal for both high-end stereo and home-theater systems.

Build quality is exceptional, with premium components, heavy-duty binding posts, and precision machining that matches its sonic pedigree. The Parasound HALO A21+ delivers the power, transparency, and refinement expected of a true reference-grade amplifier.

In Stock. For assistance or product questions, call 443-402-5055 or text 443-402-5064 to reach our team. All Elite Audio is an authorized Maryland dealer and operates a full home audio showroom.

Key Specifications
Power Output (Stereo): 300 W × 2 @ 8 ohms
Power Output (Stereo): 500 W × 2 @ 4 ohms
Power Output (Bridged Mono): 1,000 W @ 8 ohms
Frequency Response: 5 Hz – 100 kHz (+0/-3 dB)
THD: < 0.1% at full rated power
Damping Factor: > 1,100 @ 20 Hz
Input Impedance: Balanced 66 kΩ / Unbalanced 33 kΩ
Gain: 29 dB
Dimensions (W × H × D): 17-5/8" × 7-3/4" × 21-1/2"
Weight: 71 lbs
Finish: Black or Silver with Premium End Caps

Top 20 Questions About Parasound HALO A21+ Power Amplifier

What is the output power of the Parasound HALO A21+?
It delivers 300 watts per channel into 8 ohms, 500 watts per channel into 4 ohms, and 1,000 watts bridged mono into 8 ohms.

Is the Parasound HALO A21+ stable with low-impedance speakers?
Yes. It operates safely and cleanly down to 2 ohms, handling even difficult speaker loads with ease.

What circuit design does the Parasound HALO A21+ use?
It uses John Curl’s high-bias Class A/AB dual-mono design with independent power supplies per channel.

What inputs are available on the Parasound HALO A21+?
Balanced XLR and unbalanced RCA inputs are provided, plus level controls, 12 V trigger, and loop-output for system integration.

Can the Parasound HALO A21+ be used in a home-theater system?
Yes. Its high power and low noise make it perfect for front-channel duty in premium home theaters.

What is the damping factor of the Parasound HALO A21+?
It exceeds 1,100 at 20 Hz, ensuring tight, accurate bass and superior speaker control.

How large is the Parasound HALO A21+?
It measures 17-5/8" wide, 7-3/4" high, and 21-1/2" deep and weighs 71 pounds.

Does the Parasound HALO A21+ include protection features?
Yes. It has soft-start, DC-servo speaker protection, and thermal sensors to ensure long-term reliability.

What type of power supply does the Parasound HALO A21+ use?
A 1.3 kVA toroidal transformer with 108,000 µF filter capacitance delivers massive current reserves.

What is the Warranty for the Parasound HALO A21+ Power Amplifier?
It includes a five-year parts and labor warranty from All Elite Audio.

Can the Parasound HALO A21+ be bridged for mono use?
Yes. Bridging provides up to 1,000 watts into 8 ohms for ultra-high-power applications.

Which speakers pair best with the Parasound HALO A21+?
It pairs beautifully with low-sensitivity or full-range speakers that benefit from high current and control.

What are the key improvements over the previous HALO A21?
More power, larger transformer, greater filter capacitance, lower distortion, and higher signal-to-noise ratio.

Does the Parasound HALO A21+ require special cooling?
Provide adequate airflow around the chassis to maintain optimum performance during extended listening.

Which preamp matches the Parasound HALO A21+ best?
High-quality balanced preamps or processors like the Parasoubd P6  let you take full advantage of its low-noise balanced inputs.

Can it be used for bi-amping?
Yes. Independent level controls allow fine-tuned bi-amp and multi-amp configurations.

Is the Parasound HALO A21+ good for analog and digital systems?
Yes. Its transparency and low noise make it ideal for vinyl, digital, and hybrid sources.

What makes the Parasound HALO A21+ stand out?
Exceptional power, precision engineering, and refined musicality make it a benchmark amplifier in its class.

How can I get expert help before purchasing the Parasound HALO A21+?
For assistance or product questions, call 443-402-5055 or text 443-402-5064 to reach our team at All Elite Audio, your authorized Maryland dealer with a full home audio showroom.