Parasound HALO A51 Five Channel Power Amp

Parasound HALO A51 Power Amplifier

The Parasound HALO A51 Power Amplifier delivers uncompromising five-channel performance for high-end home theaters and multi-channel music systems.

The Parasound HALO A51 is a high-current, five-channel Class A/AB power amplifier designed by legendary audio engineer John Curl. It produces 250 watts per channel into 8 ohms and 400 watts per channel into 4 ohms with all channels driven, providing incredible control and musicality across every speaker in your system.

This amplifier combines the warmth of Class A with the dynamic power of Class AB for rich, detailed sound at every level. Its fully discrete circuitry, balanced signal path, and enormous 2.2 kVA toroidal transformer deliver low distortion, exceptional channel separation, and clean headroom even under demanding playback conditions.

The Parasound HALO A51 features both balanced XLR and unbalanced RCA inputs, adjustable gain controls per channel, 12V trigger, and loop outputs for flexible integration. Its THX Ultra2 certification confirms its capability for professional-level cinema sound in your home.

Silent, fanless operation and robust construction make the Parasound HALO A51 Power Amplifier a long-term reference component built to last.

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 (All Channels Driven): 250 W × 5 @ 8 ohms
Power Output (All Channels Driven): 400 W × 5 @ 4 ohms
Amplification Type: Class A/AB, high bias (first watts in Class A)
Frequency Response: 5 Hz – 100 kHz (+0 / -3 dB)
THD: < 0.2% at full rated power
Signal-to-Noise Ratio: > 112 dB (A-weighted)
Damping Factor: > 1100 @ 20 Hz
Current Capacity: 60 A peak per channel
Input Impedance: Balanced 94 kΩ / Unbalanced 47 kΩ
Inputs: 5 × XLR balanced / 5 × RCA unbalanced
Gain Adjustment: Up to +6 dB per channel
Power Supply: 2.2 kVA toroidal transformer, 164,000 µF filter capacitance
Dimensions (W × H × D): 17.25" × 7.6" × 20"
Weight: 80 lbs
Finish: Black or Silver
Certification: THX Ultra2

Top 20 Questions About Parasound HALO A51 Power Amplifier

What is the power output of the Parasound HALO A51 Power Amplifier?
It delivers 250 watts per channel into 8 ohms and 400 watts per channel into 4 ohms with all five channels driven.

Is the Parasound HALO A51 suitable for demanding speakers?
Yes. With 60 amps peak current per channel and a damping factor above 1100, it controls even the most power-hungry speakers with precision.

What class of amplification does the Parasound HALO A51 use?
The HALO A51 runs in high-bias Class A/AB, providing Class A warmth at lower levels and powerful Class AB dynamics at higher volumes.

Who designed the Parasound HALO A51 Power Amplifier?
It was engineered by John Curl, one of the most respected amplifier designers in high-end audio.

What makes the Parasound HALO A51 ideal for home theater use?
Its five identical high-current channels deliver matched performance across front and surround speakers, making it perfect for 5.1 or immersive setups.

Does the Parasound HALO A51 include balanced inputs?
Yes. It features balanced XLR and unbalanced RCA inputs for all five channels.

Is the Parasound HALO A51 THX certified?
Yes. It meets THX Ultra2 standards for reference-level accuracy and performance.

What kind of power supply does the Parasound HALO A51 use?
A 2.2 kVA toroidal transformer with 164,000 µF of filter capacitance for instantaneous current delivery and low noise.

Does the Parasound HALO A51 run quietly?
Yes. It operates silently with no cooling fan, relying on efficient heat sinks for thermal management.

Can the Parasound HALO A51 Power Amplifier be rack-mounted?
Yes. Rack handles and mounting accessories are available for custom installations.

What protection circuits are built into the Parasound HALO A51?
It includes DC offset, short circuit, and thermal protection for safe, reliable operation.

What is the frequency response of the Parasound HALO A51 Power Amplifier?
The response is 5 Hz to 100 kHz, ensuring wide bandwidth and transparency.

How heavy is the Parasound HALO A51?
It weighs approximately 80 pounds, reflecting its robust transformer and component quality.

Can I use the Parasound HALO A51 for both music and movies?
Yes. It excels equally with high-fidelity music playback and cinematic surround sound.

Does the Parasound HALO A51 Power Amplifier require special ventilation?
It runs warm and should have open space above and around for airflow, especially in enclosed cabinets.

Is the Parasound HALO A52+ a good match for AVR preamps?
Yes. It pairs perfectly with any brand AVR's that features pre outs for individual channels.

What kind of sound can I expect from the Parasound HALO A51?
The sound is powerful yet refined, with deep bass, detailed midrange, and a natural treble presentation.

Is the Parasound HALO A51 Power Amplifier easy to set up?
Yes. Connect inputs from your preamp or processor, set gains, and it’s ready to perform.

What is the Warranty for the Parasound HALO A51 Power Amplifier?
It includes a five-year parts and labor warranty from All Elite Audio.

How can I get expert help before buying the Parasound HALO A51?
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.