Halo A23+ 2 x 240W @ 4 Ohms 2 Channel Power Amp
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 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