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A 21+ Stereo Power Amplifier

Parasound A21
Halo Collection

Quick Specs

  • Type: Amplifier
  • Width: 17 1/4"
  • Height: 7 5/8"
  • Depth: 19 1/8"
  • Energy Star Rated: No

This item has purchase restrictions.

We currently only offer this product for purchase within 150 miles of our store. Questions? Contact us for more information.

 
Changes from the original A 21 A 21+
  • 250 300 Watts (8 )
  • 400 500 Watts (4 )
  • 750 1000 Watts (bridged)
  • Filter cap: 88,000 uF 108,000 uF
  • S/N: 112dB 115 dB
  • THD (at full power): 0.2% 0.1%
  • Crosstalk (20kHz): 63dB 70dB
  • Transformer size: 1.2 kVA 1.3 kVA
  • Weight: 60 LB 71 LB
  • Refined Halo cosmetic with aluminum end caps & gold highlights
  • Updated rear panel with heavy duty speaker terminals from JC 5
  • Upgraded internal gold on gold audio connections
  • Updated auto turn on circuit
All Features
  • 300 watts x 2 @ 8 RMS, both channels driven
  • 500 watts x 2 @ 4 RMS, both channels driven
  • 1000 watts x 1 @ 8 , in bridged mode
  • Circuitry designed by legendary John Curl
  • High bias Class A/AB operation
  • 60 amperes peak current per channel
  • Stable with speaker impedance dips to 1.5
  • Balanced inputs with discrete circuits
  • CHK Infinium, custom 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
  • 16 beta-matched 15 ampere, 60 MHz bipolar output transistors
  • 1.3 kVA shielded toroid transformer w/ independent windings for each channel
  • Independent power supplies for input stage, driver stage and output stage
  • 108,000 F 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
  • 4 rack space chassis with rear carry handles
  • Rack mount hardware is included
  • Available in silver or black
Power Output - Stereo Mode (0.1% THD) 300 watts x 2, 8 both channels driven
500 watts x 2, 4 both channels driven
Power Output - Bridged Mode (0.1% THD) 1000 watts x 1, 8
Bridged 4 operation is not recommended

Power measurement are at 120 VAC:
0.1% THD, RMS continuous power,
full audio band (20 Hz - 20 kHz)
Current Capacity 60 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) < 0.1 % at full power
< 0.03 % at typical listening levels
IM Distortion < 0.04 %
TIM Unmeasurable
Inter-channel Crosstalk > 80 dB at 1 kHz
> 70 dB at 20 kHz
Input Impedance Unbalanced: 33 k
Balanced: 66 k ,(33 k per leg)
Total Gain 29 dB
Input Sensitivity for 28.28 V Output into 8 Unbalanced: 1 V
Balanced: 1 V per leg
S/N Ratio > 115 dB, input shorted, IHF A-weighted
> 110 dB, input shorted, unweighted
Damping Factor > 1100 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: 17-5/8" (448 mm)
Height without feet: 7-1/8" (181 mm)
Height with feet: 7-3/4" " (197 mm)
Depth: 20" (508 mm)
Depth with cables: 21-1/2" (546 mm)
Net Weight 71 lb. (32.2 kg)
Shipping Weight 88 lb. (39.9 kg)
Power Requirement Standby: 1 Watt
Idle (no music playing): 160 Watts
Typical Listening levels: 300 Watts
Maximum: 1400 Watts

Quick Specs


  • Appearance

  • Type: Amplifier

  • Dimensions

  • Width: 17 1/4"
  • Height: 7 5/8"
  • Depth: 19 1/8"

  • Features

  • Energy Star Rated: No

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