HALO A52+ 5-Channel Power Amp
Big‑System Sound, Smaller Footprint
Drop the A52+ into your system and the whole room wakes up. Voices lock center‑stage, bass tightens without bloat, and big moments hit with the kind of weight that turns movie night into a grin‑inducing event—no rack overhaul required.
Designed by John Curl, the A52+ runs high‑bias Class A/AB in a direct‑coupled topology for effortless clarity. It delivers 180 W x5 into 8 Ω (255 W x5 into 4 Ω) with a custom 1.5 kVA toroidal transformer (independent secondary windings per channel) and 100,000 µF of reserve for clean current on demand. Full power is rated down to 5 Hz, and integration is simple: five XLR + five RCA inputs, plus 12 V trigger or audio‑sense auto‑on for any AVR/processor with pre‑outs.
Praised by audiophiles and reviewers alike:
- “Delivers clear, dynamic sound and has plenty of headroom to handle the explosive effects in movie soundtracks.” — Sound & Vision (Al Griffin).
- “Overall, I really liked Parasound’s Halo A 52+ in every way.” — Stereophile (Kalman Rubinson).
Power Output - All 5 Channels Driven
180 watts x 5, 8 Ω
255 watts x 5, 4 Ω
Power Output - 2 Channels Driven
225 watts x 2, 8 Ω
350 watts x 2, 4 Ω
Power measurements parameters with 120VAC
0.05% THD, RMS continuous power,
full audio band (20 Hz - 20 kHz)
Current Capacity:
45 amperes peak, per channel
Dynamic Headroom:
>1.5dB
Slew Rate
> 130 volts per microsecond
Frequency Response
5 Hz - 100 kHz, +0/-3 dB
20 Hz - 20 kHz, +0/-0.3 dB
Total Harmonic Distortion (THD)
< 0.05 % at full power
< 0.03 % at typical listening levels
IM Distortion
< 0.04 %
TIM
Unmeasurable
Interchannel Crosstalk
> 78 dB at 1 kHz
> 63 dB at 20 kHz
Input Impedance
Unbalanced: 47 kΩ
Balanced: 94 kΩ, 47 kΩ per leg
Input Sensitivity for 28.28 V Output into 8 Ω
Unbalanced: 1 V
Balanced: 1 V per leg
Total Gain: 29 dB
S/N Ratio
> 112 dB, input shorted, IHF A-weighted
> 102 dB, input shorted, unweighted
Damping Factor
> 1100 at 20 Hz
DC Trigger Requirements
+9 Vdc to +12 Vdc, 5 mA
Audio Trigger Requirements
2 mV - 10 mV
XLR Pin Identification
1 = Ground (Shield)
2 = Positive
3 = Negative (Return)
Dimensions
Width: 17-1/4" (437 mm)
Height without feet: 5-1/4" (133 mm)
Height with feet: 5-7/8" (149 mm)
Depth: 20" (508 mm)
Depth with cables: 21-1/4" (540 mm)
Net Weight
55 lb. (25 kg)
Shipping Weight
69 lb. (31.3 kg)
Power Requirement
Standby: 1 Watt
Idle: 125 Watts
Maximum: 1500 Watts
- 180 watts RMS x 5 @ 8 Ω
- 255 watts RMS x 5 @ 4 Ω
- 225 watts RMS x 2 @ 8 Ω
- 350 watts RMS x 2 @ 4 Ω
- Class A/AB circuitry designed by legendary John Curl
- Direct coupled - no capacitors or inductors in audio path ensures the cleanest signal
- Balanced XLR inputs with discrete circuits
- Full power is rated all the way down to 5Hz for unrestricted low-end bass
- Custom 1.5 kVA encapsulated toroid power transformer with independent secondary windings for each channel
- Hand-matched JFETs for input stage
- Hand-matched MOSFETs for driver stage
- Beta-matched 15 amp, 60 MHz bipolar output transistors (3 pairs per channel)
- 100,000 µF power supply filter capacitance
- DC Servo and relay protection circuits
- Auto turn on by audio signal or 12V trigger
- Heavy-duty 24k gold-plated, 5-way speaker terminals
- 3U chassis with updated cosmetics, rack mountable with HRA3 (sold separately)
HiFi Review (HK) December 2018
"If you are pursuing a cost-effective multi-channel amplifier, the A 52+ is a trust-worthy great value five-channel amplifier that worth having!"
Enjoy the Music July 2018
"At all volumes, the Parasound A52+ amplifier never gave ground, nor quarter, to the Martin Logan Summits. Electrostatic speakers are notorious power hogs, and the Martin Logan Summits are no exception. They are uniquely talented at exposing any amplifier weaknesses. Impressively, the Parasound A52+ five-channel amplifier didn't flinch."
Stereophile May 2018
"The Halo A 52+ provided all the power that my speakers could handle, and did so with aplomb. The soundstage was consistent with no blurring of individual voices or instrumental details. The new Parasound showed its superiority in more graceful smoothness in the upper midrange and treble, and low bass that seemed better integrated with the upper bass. Overall, I really liked Parasound's Halo A 52+ in every way."
Sound and Vision April 2018
"Listening with the Halo A 52+ in my system was a pleasure. Intense dynamic contrasts literally caused me to sit up straight on my couch. Stereo and multichannel music also sounded great, making it a versatile all-around performer for entry-level and advanced home theaters alike."