Parasound - HALO A23+ - Power Amplifier

The Halo A 23+ power amplifier combines exceptional power and performance. With two channels delivering 125 watts per channel into 8 Ω, it offers a compelling audio experience. The high bias Class A/AB operation ensures accurate and detailed sound reproduction. Its stable operation into 2 Ω loads provides flexibility for various speaker configurations. The direct-coupled design, free from capacitors in the signal path, maintains signal purity and enhances transparency. With balanced XLR and unbalanced RCA inputs, it offers versatility and compatibility. Experience exceptional power and performance with the Halo A 23+ power amplifier.- Two channels @ 125 watts per channel @ 8 Ω

- High bias Class A/AB operation

- Stable into 2 Ω loads

- Direct-coupled without capacitors in the signal path

- Balanced XLR and unbalanced RCA inputs

- A/B speaker terminals

Changes from the original A 23→A 23+

• 125 → 160 Watts (8Ω)
• 225 → 240 Watts (4Ω)
• 400 → 500 Watts (bridged)
• Filter cap: 40,000 uF →54,400 uF
• Crosstalk (20kHz): 63dB → 70dB
• Transformer size: 1.0 kVA → 1.1 kVA
• Refined Halo cosmetic with aluminium end caps & gold highlights
• Updated rear panel with heavy duty speaker terminals from HINT 6
• Upgraded internal gold on gold audio connections
• Updated auto turn on circuit

Features

• 160 watts x 2 @ 8 Ω RMS, both channels driven
• 240 watts x 2 @ 4 Ω RMS, both channels driven
• 500 watts x 1 @ 8 Ω, in bridged mode
• Circuitry designed by legendary John Curl
• High bias Class A/AB operation
• 45 amperes peak current per channel
• Stable with speaker impedance dips below 2 Ω
• Balanced inputs with discrete circuits
• Heavy-duty 24k gold-plated 5-way speaker binding posts
• Gold-plated RCA input & loop output jacks
• Direct-coupled signal path, no capacitors or inductors
• DC Servo and relay protection circuits
• AC turn-on inrush surge protection with relay bypass
• JFET input stage, MOSFET driver stage
• 12 beta-matched 15 ampere, 60 MHz bipolar output transistors
• 1.1 kVA shielded toroid transformer w/ independent windings for each channel
• Independent power supplies for input stage, driver stage and output stage
• 54,400 µF filter capacitors for output stages
• Full power is rated all the way down to 5Hz for unrestricted low-end bass
• Harris hyper-fast soft-recovery bridge diode rectifiers
• Automatic turn-on by 12 V trigger or audio sensing
• 2 rack space chassis with rear carry handles
• Rack mount hardware available separately
• Available in black

Specifications

Power Output – Stereo Mode (0.06% THD): 160 watts x 2, 8 Ω both channels driven; 240 watts x 2, 4 Ω both channels drivenPower Output – Stereo Mode (0.9% THD): 210 watts x 2, 8 Ω both channels driven; 300 watts x 2, 4 Ω both channels drivenPower Output – Bridged Mode (0.06% THD): 500 watts x 1, 8 Ω: Bridged 4 Ω operation is not recommendedPower Output – Bridged Mode (0.9% THD): 600 watts x 1, 8 Ω; Bridged 4 Ω operation is not recommended (*All Power measurement are at 120 VAC, RMS continuous power, full audio band (20 Hz - 20 kHz))Current Capacity: 45 amps peak, per channelSlew Rate: > 130 volts per microsecondFrequency Response: 5 Hz - 100 kHz, +0/-3 dB; 20 Hz - 20 kHz, +0/-0.25 dBTotal Harmonic Distortion (THD): < 0.06 % at full power; < 0.03 % at typical listening levelsIM Distortion: < 0.04 %TIM: UnmeasurableInter-channel Crosstalk: > 85 dB at 1 kHz, > 70 dB at 20 kHzInput Impedance: Unbalanced: 33 kΩ, Balanced: 66 kΩ,(33 kΩ per leg)Total Gain: 29 dBInput Sensitivity for 28.28 V Out (8 Ω Load): Unbalanced: 1 V, Balanced: 1 V per legS/N Ratio: > 112 dB, input shorted, IHF A-weighted; > 107 dB, input shorted, unweightedDamping Factor: > 800 at 20 HzDC Trigger Requirements: +9 Vdc to +12 Vdc, 5 mAAudio Trigger Requirements: 2 mV - 10 mVXLR Pin Identification: 1 = Ground (Shield), 2 = Positive, 3 = Negative (Return)Dimensions: Width: 17-1/4" (437 mm), Depth: 15"-1/4" (388 mm), Depth, with cables 17" (432 mm), Height, with feet: 4-1/8" (105 mm), Height, without feet: 3-1/2" (89 mm), 2UNet Weight: 27 lb. (12.2 kg)Power Requirement: Standby: <1 Watt, Idle (no music playing): 75 Watts, Typical Listening levels: 125 Watts, Maximum: 800 Watts, 110-125 VAC 60 Hz or 220-250 VAC 50 Hz (AC mains voltage is set on rear panel)