Parasound Halo A 23+

Features:

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

Specs:

Power Output – Stereo Mode (0.06% THD)
160 watts x 2, 8 Ω both channels driven
240 watts x 2, 4 Ω both channels driven Power Output – Stereo Mode (0.9% THD)
210 watts x 2, 8 Ω both channels driven
300 watts x 2, 4 Ω both channels driven Power Output – Bridged Mode (0.06% THD)
500 watts x 1, 8 Ω
Bridged 4 Ω operation is not recommended Power 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