Power amplifiers stereo — Parasound HALO A51

The HALO A51 is a stereo power amplifier from Parasound, sharing the HALO A31's electrical specifications within a somewhat deeper chassis. The HALO A51 brings Parasound's considered engineering to dedicated stereo power amplification.

Key specs that matter

Input sensitivity is 1,000mV, matching the HALO A31. Input impedance is 94,000 ohms balanced or 47,000 ohms single-ended, also matching. Output power is 250W into 8 ohms, rising to 400W into 4 ohms, also matching. Signal-to-noise ratio is 112dB, matching. Damping factor exceeds an extraordinary 1,100, also matching. At 194 x 445 x 508mm and 36.3kg, the HALO A51 is somewhat deeper and heavier than the HALO A31 despite matching electrical performance.

Sound and use context

Expect exceptionally clean, tightly controlled amplification reflecting the extraordinary over-1,100 damping factor, matching the HALO A31's electrical performance within a somewhat more substantial chassis.

Pairing

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

Alternatives

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