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
300 watts per channel @ 8 ohms | 500 watts @ 4 ohms
1,000 watts bridged mono into 8 ohms
Stable down to 2 ohms, making it ideal for difficult speaker loads
🔹 Refined John Curl Circuit Design
High bias Class A/AB topology for smoother, richer sound
Fully discrete circuitry with dual-mono construction for optimal separation and dynamics
Balanced XLR and unbalanced RCA inputs with gold-plated connectors
🔹 Low Noise, High Damping Factor
Superior control over bass drivers thanks to high damping factor
Quiet operation with minimal distortion across the frequency range
Fast transient response makes music feel immediate and alive
🔹 Built to Perform
Heavy-duty toroidal power transformer
High-speed soft-recovery bridge rectifiers
Audiophile-grade 1% precision resistors and capacitors
Independent power supplies for each channel
🔹 Flexible for Any System
Works with any high-end preamp or surround processor
Perfect for stereo, bi-amp, or home theater front-channel configurations
Trigger input and loop output for integration into automated systems
🟦 Performance Specifications
🔹 Power Output
300W @ 8 ohms per channel
500W @ 4 ohms per channel
1000W @ 8 ohms bridged mono
🔹 Distortion & Bandwidth
Total Harmonic Distortion: < 0.1% at full rated power
Frequency Response: 5 Hz – 100 kHz, +0/-3 dB
🔹 Input Impedance
Balanced XLR: 66 kΩ per leg
Unbalanced RCA: 33 kΩ
🔹 Signal-to-Noise Ratio
112 dB, input shorted, IHF A-weighted
🔹 Damping Factor
1100 @ 20 Hz
🟦 Design & Build Quality
🔹 Dimensions:
17.25" W x 21.25" D (with handles) x 7.625" H (with feet)
🔹 Weight:
Net: 71 lbs | Shipping: 83 lbs
🔹 Finish:
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.
