A 23+ Stereo Power Amplifier
Halo
A 23+
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
LowBeats (Germany) November 2020
"the Parasound P 6 and Parasound A 23+ play together in a pleasingly balanced and precise manner, while still musical with tonality that tends toward warmth. The consistently very supple reproduction and simultaneously true-to-size presentation and pin-point positioning of individual instruments and voices is amazing. Yes, this is how HiFi is fun."
» English Translation PDF
Secrets of Home Theater & High Fidelity, November 2020
"There is a lot to like in the reasonably-priced Parasound HALO A 23+ stereo amplifier. It is stylish, packs sufficient amplification power, and delivers solid high-fidelity sonic performance."
ON-OFF (Spain) September, 2019
"One strength is its capability to reproduce a wide sonic palette, with depth and plenty of micro information. Parasound's power amp is able to bring out the best bass from speakers. Different kinds of music made us appreciate the unusual character of this amplification. Outstanding!"
Soundstage Network July 2019
Reviewer's Choice
"Parasound provides great value in the Halo A 23+. I haven't heard better sound or seen higher build quality at this price. An impressive power amplifier."
Stereo+ (Norway) January 2019
"Together, the Parasound P 6 and A 23+ are dynamite. Pure sonic magic with brilliant dynamics, delicious midrange and impressive resolution. To get such good sound for the price of this duo seems almost unnatural. One incredibly appealing preamp-amplifier package from Parasound."
