Parasound Halo A23+ 2 Channel Power Amplifier

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 aluminum 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

All 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 silver or black
• 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 channel
• Slew Rate
  > 130 volts per microsecond
• Frequency Response
  5 Hz – 100 kHz, +0/-3 dB
  20 Hz – 20 kHz, +0/-0.25 dB
• Total Harmonic Distortion (THD)
  < 0.06 % at full power
  < 0.03 % at typical listening levels
• IM Distortion
  < 0.04 %
• TIM
  Unmeasurable
• Inter-channel Crosstalk
  > 85 dB at 1 kHz
  > 70 dB at 20 kHz
• Input Impedance
  Unbalanced: 33 kΩ
  Balanced: 66 kΩ,(33 kΩ per leg)
• Total Gain
  29 dB
• Input Sensitivity for 28.28 V Out (8 Ω Load)
  Unbalanced: 1 V
  Balanced: 1 V per leg
• S/N Ratio
  > 112 dB, input shorted, IHF A-weighted
  > 107 dB, input shorted, unweighted
• Damping Factor
  > 800 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)
  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), 2U
• Net Weight
  27 lb. (12.2 kg)
• Shipping Weight
  34 lb. (14.4 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