Parasound A21+ Stereo Power Amplifier
Clean and powerful, the A21+ outputs 300 Watts at 8 Ohms, 500 at 4, and up to 1,000 Watts bridged. This is supported by the high bias class A-AB operation and the amplifiers direct-coupled signal path, with no capacitors or inductors.
To ensure system quality and longevity, the A21+ also features an updated auto turn on circuit in conjunction with DC servo and relay protection circuits. This updated turn on circuit contains an AC turn-on inrush surge protector with relay bypass.
As for power, a 1.3kVA shielded toroidal transformer with an independent winding for each channel offers up to 1000 Watts, with unrestricted full power output reaching all the way down to 5Hz. The input stage, driver stage, and output stage each have independent power supplies within the A21+.
Full Features and Specifications
• 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 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 black