The Parasound HALO A21+ isn’t just an amplifier—it’s a full-force powerhouse built to deliver clean, controlled energy to any speaker you throw at it. With 300 watts per channel into 8 ohms (500W into 4 ohms) and a circuit designed by legendary engineer John Curl, the A21+ has the muscle, finesse, and musicality to elevate any listening space. Whether you're building a reference two-channel setup or anchoring the front end of a high-performance home theater, the A21+ is your foundation for breathtaking sound.
🟦 Key Features
🔹 Massive Two-Channel Power
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300 watts per channel @ 8 ohms | 500 watts @ 4 ohms
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1,000 watts bridged mono into 8 ohms
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Stable down to 2 ohms, making it ideal for difficult speaker loads
🔹 Refined John Curl Circuit Design
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High bias Class A/AB topology for smoother, richer sound
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Fully discrete circuitry with dual-mono construction for optimal separation and dynamics
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Balanced XLR and unbalanced RCA inputs with gold-plated connectors
🔹 Low Noise, High Damping Factor
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Superior control over bass drivers thanks to high damping factor
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Quiet operation with minimal distortion across the frequency range
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Fast transient response makes music feel immediate and alive
🔹 Built to Perform
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Heavy-duty toroidal power transformer
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High-speed soft-recovery bridge rectifiers
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Audiophile-grade 1% precision resistors and capacitors
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Independent power supplies for each channel
🔹 Flexible for Any System
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Works with any high-end preamp or surround processor
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Perfect for stereo, bi-amp, or home theater front-channel configurations
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Trigger input and loop output for integration into automated systems
🟦 Performance Specifications
🔹 Power Output
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300W @ 8 ohms per channel
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500W @ 4 ohms per channel
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1000W @ 8 ohms bridged mono
🔹 Distortion & Bandwidth
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Total Harmonic Distortion: < 0.1% at full rated power
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Frequency Response: 5 Hz – 100 kHz, +0/-3 dB
🔹 Input Impedance
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Balanced XLR: 66 kΩ per leg
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Unbalanced RCA: 33 kΩ
🔹 Signal-to-Noise Ratio
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112 dB, input shorted, IHF A-weighted
🔹 Damping Factor
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1100 @ 20 Hz
🟦 Design & Build Quality
🔹 Dimensions:
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17.25" W x 21.25" D (with handles) x 7.625" H (with feet)
🔹 Weight:
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Net: 71 lbs | Shipping: 83 lbs
🔹 Finish:
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Sleek silver or black chassis with sandblasted aluminum end caps and subtle gold accents
From jazz trios to film scores, from intimate acoustic sessions to arena-level rock, the Parasound HALO A21+ delivers the depth, scale, and authority that brings every recording to life. If you're ready to hear what your speakers are truly capable of—this is the amp to do it.
