Parasound Halo A52+ Multi Channel Amplifier

Parasound Halo A52+ Multi Channel Amplifier

The Parasound HALO A52+ is a new addition for 2018 to the HALO multichannel stable. The A 52+ is based on Parasound's previous and highly successful A 52 model, and features significant upgrades in power output, circuitry refinements, and of course features the latest Halo styling.

The new model increases available power from 125 to 180 watts per channel into 8 ohms and 255 watts into 4 ohms, with all channels driven. As with its predecessor, the Parasound Halo A 52+ is the work of audio legend John Curl, using high-bias Class A/AB and direct-coupled circuit topology.

The Parasound Halo A 52+ features a larger custom-made toroidal power transformer to support its higher power output. It has five RCA unbalanced and five balanced XLR inputs, a separate module for each channel, DC Servos and relays to protect the amp and speakers. Features include automatic turn-on, a 3U chassis with rear carry handles which is rack mountable with optional adaptors.

The Parasound Halo A 52+ has a black anodized extruded front panel with new solid aluminum end-caps that are milled and hand-polished. These represent a fresh and refined Halo aesthetic.

Features:

• 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)

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