Halo is Parasound’s premier line with a reputation for going head-to-head with the most expensive equipment on the market, while costing a fraction of the price. Halo has earned honors and awards that are unmatched.
Halo is Parasound’s premier line with a reputation for going head-to-head with the most expensive equipment on the market while costing a fraction of the price. Halo has earned honors and awards that are unmatched. The Halo A series is a high-performance Class A/AB multi-channel amplifier. We are very proud of this achievement of Parasound engineering in concert with legendary audio equipment designer John Curl. John Curl has been designing for Parasound since 1989. He was already a legend in the '70s for designing and building mixing consoles for The Grateful Dead and Jefferson Airplane. He has designed some of the most iconic and highest regarded audio equipment in the world. Curl’s inspired designs have earned Parasound world-wide acclaim and our stunning A Series builds on this storied heritage.
Recording and broadcast studios use balanced connections exclusively because of their inherent ability to reject noise and hum, thus assuring the best sound. Certain high-quality preamplifiers and surround controllers built for residential use utilize balanced connections with XLR jacks for the same reasons. All Parasound Halo series power amplifiers have balanced inputs with XLR jacks so you can take full advantage of their inherent noise reduction capability.
To unleash greater dynamics, the A Series has a total of up to 164,000uF electrolytic filter capacitors, chosen for their low Equivalent Series Resistance (ESR), dielectric absorption and resistance to high temperature. In addition, these filter capacitors are bypassed with smaller polypropylene capacitors to reduce AC ripple in the DC supply and to further eliminate noise and interference that is generated in AC power lines from computers and other appliances in the home.
Every part within the A Series is carefully chosen for its accuracy, sound quality and long life. Its heavy-duty speaker terminals provide ample size and width to accommodate even the largest gauge speaker wire or spade connectors. High quality 24 K gold-plating on the speaker terminals, input connectors and internal audio signal connections assure sound quality that won’t be compromised by corrosion.
The heart of the A Series power supply is a massive toroid power transformer up to 2.2 kVA. It is custom designed for well-contained radiated hum, high efficiency, and high power. The transformer has independent secondary windings and this provides more than ample voltage to each channel's power supply under the most strenuous operating conditions. Separate windings for each channel improves stereo imaging by reducing interchannel crosstalk and allows each channel to deliver up to 400 watts per channel at the same time.
The setting of the rear panel Turn On Options switch determines how the amplifier turns on and off. There are three options for this switch. 1) Manually by the front panel power button. 2) By connecting a 12V trigger. 3) Automatically when an audio signal is detected at the L or R Input jacks.
PARA-A31 | PARA-A51 | PARA-A52P |
---|---|---|
5U |
5U |
4U |
3-Channel |
5-Channel |
5-Channel |
301-500W |
301-500W |
201-300W |
250W RMS x 3, 20 Hz - 20 kHz, 8 Ω, all channels driven |
250W RMS x 5, 20 Hz - 20 kHz, 8 Ω, all channels driven |
180W RMS x 5, 20 Hz - 20 kHz, 8 Ω, all channels driven |
400W RMS x 3, 20 Hz - 20 kHz, 4 Ω, all channels driven |
400W RMS x 5, 20 Hz - 20 kHz, 4 Ω, all channels driven |
255W RMS x 5, 20 Hz - 20 kHz, 4 Ω, all channels driven |
n/a |
n/a |
n/a |
Standby: 1W
Maximum: 1800W |
Standby: 25 Watts Full Power into 4Ω: 3000 Watts |
Standby: 1W Idle: 125W Maximum: 1500W |
60 amps peak, per channel |
60 amps peak, per channel |
45 amps peak, per channel |
< 0.2 % at full power < 0.03 % at typical listening levels |
< 0.2 % at full power |
0.05% THD, RMS continuous power,
full audio band (20 Hz - 20 kHz) |
Yes |
Yes |
Yes |
5 Hz - 100 kHz, +0/-3 dB at 1W |
5 Hz - 100 kHz, +0/-3 dB at 1W |
5 Hz - 100 kHz, +0/-3 dB 20 Hz - 20 kHz, +0/-0.3 dB |
> 78 dB at 1 kHz > 63 dB at 20 kHz |
> 78 dB at 1 kHz > 63 dB at 20 kHz |
> 78 dB at 1 kHz > 63 dB at 20 kHz |
Unbalanced: 47k Ω Balanced: 94k Ω per leg |
47 k Ω unbalanced 94 k Ω balanced |
Unbalanced: 47 kΩ Balanced: 94 kΩ, 47 kΩ per leg |
29 dB |
29 dB |
29 dB |
for 28.28 V Output into 8Ω Unbalanced: 1 V Balanced: 1 V per leg (Gain controls set to Normal / THX) |
Unbalanced: 1 V Balanced: 1 V per leg |
Unbalanced: 1 V Balanced: 1 V per leg |
> 112 dB, input shorted, IHF A-weighted > 102 dB, input shorted, unweigh |
> 112 dB, input shorted, IHF A-weighted > 102 dB, input shorted, unweigh |
> 112 dB, input shorted, IHF A-weighted > 102 dB, input shorted, unweigh |
Audio Trigger: 2 mV AC - 10 mV AC |
Audio Trigger: 50 mV AC - 250 mV AC |
Audio Trigger: 2 mV - 10 mV |
+9 Vdc to +12 Vdc, 2 mA |
+9 Vdc to +12 Vdc, 2 mA |
+9 Vdc to +12 Vdc, 2 mA |
XLR Pin Identification 1 = Ground (Shield) 2 = Positive 3 = Negative (Return) |
XLR Pin Identification 1 = Ground (Shield) 2 = Positive 3 = Negative (Return) |
XLR Pin Identification 1 = Ground (Shield) 2 = Positive 3 = Negative (Return) |
17.5" x 7" x 19.13" (445 x 178 x 485mm) (without feet) 17.5" x 7.63" x 19.13" (445 x 194 x 485mm) (with feet) |
17.5" x 7" x 20" (445 x 178 x 508mm) (without feet) 17.5" x 7.63" x 20" (448 x 194 x 508mm) (with feet) |
17.25" x 5.25" x 20" (437 x 133 x 508mm) (without feet) 17.25" x 5.88" x 20" (437 x 149 x 508mm) (with feet) Depth with cables: 21.25" (540mm) |
Net Weight:65 lbs (29.5 kg) Shipping Weight: 79 lbs (35.9 kg) |
Net Weight: 80 lbs (36.4 kg) Shipping Weight: 87 lbs (39.5 kg) |
Net Weight: 55 lbs (25 kg) Shipping Weight: 69 lbs (31.3 kg) |
Rack Spacing |
Channels |
Watts Per Channel |
Power Output @ 8 ohm |
Power Output @ 4 ohm |
Power Output Bridged @ 8 ohm |
Power Consumption |
Current Rating |
Total Harmonic Distortion (THD) |
Power RMS |
Frequency Response |
Audio Crosstalk |
Impedance Input |
Audio Gain |
Sensitivity Input |
Signal to Noise Ratio |
Amplifier Requirements |
External Trigger Voltage |
Connectors |
Dimensions (W x H x D) |
Weight |
We want to make our Affiliate program as easy as possible. That’s why we process all claims directly, without any third party telephone tag. Specific warranty terms and details from the manufacturer are below. View the full Parasound Warranty.
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