Parasound A21+ 2 Channel Power Amplifier

• 250 → 300 Watts (8Ω)
• 400 → 500 Watts (4Ω)
• 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 Ω RMS, both channels driven
• 500 watts x 2 @ 4 Ω RMS, both channels driven
• 1000 watts x 1 @ 8 Ω, in bridged mode
• CircuHigh bias Class A/AB operation
• 60 amperes peak current per channel
• Stable with speaker impedance dips to 1.5 Ω
• 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 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
• 4 rack space chassis with rear carry handles
• Rack mount hardware is included
• Available in silver or blackitry designed by legendary John Curl

Power Output – Stereo Mode (0.1% THD) 300 watts x 2, 8 Ω both channels driven 500 watts x 2, 4 Ω both channels driven

Power Output – Bridged Mode (0.1% THD) 1000 watts x 1, 8 Ω Bridged 4 Ω 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 kΩ Balanced: 66 kΩ,(33 kΩ per leg)

Total Gain 29 dB

Input Sensitivity for 28.28 V Output into 8 Ω 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