Parasound A21 Plus 2 Channel Power Amplifier

The Parasound A21 Plus takes one of our favourite 2 channel amplifiers the “A21” to a whole new level. The A21 + has more power better THD, less cross talk and a larger power supply. We thought the “A21” was special and when hearing the “+” version for the first time the performance levels are mind-blowing for the price

Parasound A21 Plus Key Information:

Changes from the original A 21→A 21+

• 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 aluminium 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
• 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 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 amperes, 60 MHz bipolar output transistors
• 1.3 kVA shielded toroid transformer w/ independent windings for each channel
• Independent power supplies for the 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
• Rackmount hardware is included
• Available in silver or black