Power amplifiers stereo — Parasound HALO A21+

The HALO A21+ is a stereo power amplifier from Parasound, part of the celebrated Halo series, built with an extraordinary damping factor and substantial output power. The HALO A21+ brings Parasound's more accomplished current engineering to dedicated stereo power amplification.

Key specs that matter

Input sensitivity is 1,000mV, with input impedance at 66,000 ohms balanced or 33,000 ohms single-ended. Output power is a substantial 300W into 8 ohms, rising to 500W into 4 ohms. Gain is 29dBu. Frequency response spans a wide 5Hz to 100,000Hz within plus-or-minus 3dB. Signal-to-noise ratio exceeds 115dB, with total harmonic distortion plus noise under 0.1% at 100% global feedback. Damping factor exceeds an extraordinary 1,100. At 448 x 181 x 197mm and 32.2kg, the HALO A21+ represents a serious power amplifier commitment reflecting Parasound's celebrated Halo-series engineering.

Sound and use context

Expect exceptionally clean, tightly controlled amplification reflecting the extraordinary over-1,100 damping factor combined with the substantial 500W-into-4-ohms output, representing Parasound's more accomplished current Halo-series engineering.

Pairing

The extraordinary over-1,100 damping factor suits demanding loudspeaker loads with excellent bass control.

Alternatives

Parasound's own HALO A31 offers a related model within the same broader Halo power amplifier catalogue.