Parasound Halo A 23+ Stereo Amplifier

This Halo Shines More Beautifully Than Ever

Parasound already brings listeners heavenly sound, but its halo now shines more beautifully than ever with its brand new version of the Halo A 23 two-channel power amplifier. Meet the Halo A 23+ and enjoy performance upgrades for cleaner, ultra-low distortion sound, revised front panel cosmetics, and a revised rear panel layout offering enhanced features, too.

"Together, the Parasound P 6 and A 23+ are dynamite," raves Roy Ervin Solstad, Stereo+ (Norway), January 2019. "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."

Impressive Performance Upgrades

The performance upgrades are impressive, beginning with a big 25% to 30% increase in output power compared to the previous model. The A 23+ delivers 160 watts-per-channel at 8 ohms compared to 125 watts-per-channel for the A 23, 240 watts-per-channel compared to 225 watts-per-channel at 4 ohms, and 500 watts in bridged mono mode compared to 400 watts with the A 23.

The performance of a power amplifier is highly dependent on the quality of its power supply, and Parasound went the extra mile with the A 23+, which boasts a 10% to 15% larger main power transformer compared to the previous model A 23. Transformer size has been increased from 1.0 to 1.1kVA, and the filter capacitance increases 20-30% from 40,000 uF for the A 23 to 54,400 uF for the new A 23+. You'll hear the advantages of these upgrades as the A23+ presents lower distortion at full power.

Other performance upgrades include tweaked input circuits for improved crosstalk specs (70 dB at 20 kHz compared to 63 dB) and upgraded internal gold on gold audio connections, resulting in a cleaner signal path that's also more reliable.

Rear Panel Layout and Features Upgrades

The rear panel of the A 23+ has been revised in terms of layout and new features. It boasts upgraded speaker terminals, using identical terminals to the HINT 6 integrated amp, a new jack/terminal layout with more space and more clear text/labels, and a master "Vacation" AC switch. The 2.5mm trigger jacks of the A 23 have been replaced with 3.5mm jacks, and the audio trigger circuit has been updated for better low signal reliability.

Revised Halo Front Panel Cosmetics

The Halo series has always been known for its elegant aesthetics, and the look is even better than before. New front panel cosmetics include slim metal end caps replacing wider plastic end caps, an added gold metallic accent stripe along the end cap, gold feet now on black units, and an engraved metal "Parasound" badge replacing the red "P."

Advanced John Curl-Designed Circuitry

The circuitry of the A 23 was engineered by legendary audio designer John Curl. Its direct-coupled topology uses no capacitors or inductors in the signal path for pure, uncolored sound. Balanced inputs with discrete circuits and XLR connectors yield dead quiet operation. The complementary JFET input stage and MOSFET drive stage incorporates 12 beta-matched 15 amp, 60 MHz bipolar output transistors for pristine sound. The high-bias "Class A"/"Class AB" operation blends best sound with highest efficiency performance.

The A 23's custom-made, high-current power supply is specially designed for exceptionally quiet operation along with ample power for climactic music passages. The 1.1KVA encapsulated toroidal power transformer uses independent secondary windings for each channel along with a 54,400 µF power supply filter capacitance. DC servo and relay protection circuits keep operation safe and reliable. And Parasound backs the A 23+'s reliability with an impressive warranty.

No Need for a Remote

The front panel of the A 23+ looks great even when the unit is turned off. When you switch the Halo on, LEDs display AC-present, channel, and high temperature status. Adjustable signal sensing can be set to automatically power up the A23 when it receives a signal from your preamp or other compatible component (or when it receives a 12-volt trigger command), eliminating the need for yet another wireless remote!

'Instant Warm-up' Feature

Like all the other amps in the Halo product series, the A 23+ has Parasound's exclusive bias circuit, which permits the amplifier to sound perfect from the instant it's turned on, rather than having to wait for bias to gradually build up as the amp warms up over time. Even Halo's implementation of its automatic turn-on feature is exceptional. Special relays bypass the AC "soft start" circuitry after it's done its job for the purest AC and the purest sound.

A23+ Performance Upgrades

• Power up 25-30%
• Filter capacitance up 20-30%
• 10-15% Larger main power transformer
• Upgraded internal gold on gold audio connections (cleaner signal path and more reliable)
• Tweaked input circuits for Improved Crosstalk specs
• Improved power supply for lower distortion at full power
• Filter capacitance: 54,400 uF
• Transformer size: 1.1kVA

• Slim metal end caps replace wider plastic end caps
• Added gold metallic accent stripe along end cap
• Engraved metal PARASOUND badge replaces the red P
• Gold feet now on black units

• Upgraded speaker terminals (A23+ gets HINT 6 terminals)
• New jack/terminal layout with more space and more clear text/labels
• 2.5mm trigger jacks replaced with 3.5mm jacks
• Audio trigger circuit has been updated for better low signal reliability
• Master AC "vacation" switch on the rear panel

Power Output – Stereo Mode (0.06% THD)

• 160 watts x 2, 8Ω both channels driven
• 240 watts x 2, 4Ω both channels driven

• 500 watts x 1, 8Ω
• Bridged 4 Ω operation is not recommended

• 210 watts x 2, 8Ω both channels driven
• 300 watts x 2, 4Ω both channels driven

• 600 watts x 1, 8Ω
• Bridged 4 Ω operation is not recommended
• All Power measurement are at 120 VAC, RMS continuous power, full audio band (20 Hz - 20 kHz)

• 45 amps peak, per channel

• > 130 volts per microsecond

• 5Hz - 100kHz, +0/-3dB 20Hz - 20kHz, +0/-0.25dB

• < 0.06% at full power
• < 0.03% at typical listening levels

• < 0.04%

• Unmeasurable

• > 85dB at 1kHz
• > 70dB at 20kHz

• Unbalanced: 33kΩ
• Balanced: 66kΩ,(33kΩ per leg)

• 29dB

• Unbalanced: 1 V
• Balanced: 1V per leg

• > 112dB, input shorted, IHF A-weighted
• > 107dB, input shorted, unweighted

• > 800 at 20 Hz

• +9 Vdc to +12 Vdc, 5 mA

• 2 mV - 10 mV

• 1 = Ground (Shield)
• 2 = Positive
• 3 = Negative (Return)

• Width: 17-1/4"
• Depth: 15”-1/4”
• Depth, with cables 17”
• Height, with feet: 4-1/8”
• Height, without feet: 3-1/2”, 2U
• Weight: 27 lbs.

• Standby: 1 Watt
• Idle (no music playing): 75 Watts
• Typical Listening levels: 3125 Watts
• Maximum: 800 Watts

"There is a lot to like in the reasonably-priced PARASOUND HALO A23+ STEREO AMPLIFIER. It is stylish, packs sufficient amplification power, and delivers solid high-fidelity sonic performance."

"Parasound’s tradition of offering good quality and high value audio components continues in the A23+ amplifier. This amplifier is well built and looks stylish with its gold accent lines and lettering. In general, the sonic attributes of the A23+ score highly in my scorecard. The A23+ delivers neutral-character vivid sounds with excellent dynamics. Sonic presentation seems well balanced across the audible frequency spectrum with extended treble and punchy bass. It is capable of portraying satisfying soundstage too."

- Yongki Go, P.H.D., Secrets of Home Theater and High Fidelity, November 18, 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."

- Raphael Vogt, Low Beats, November 2020

"Parasound provides great value in the Halo A 23+ power amplifier. Always detailed, accurate and balanced. I haven’t heard better sound or seen higher quality at this price. An impressive power amplifier."

- Sathyan Sundaram, SoundStage! Access, September 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."

- Roy Ervin Solstad, Stereo+ (Norway), January 2019