Parasound Halo A21+ Stereo Power Amplifier in Silver (Demo)
Showroom demo high-current Class A/AB stereo power amplifier • John Curl circuit topology • 300W x 2 into 8Ω / 500W x 2 into 4Ω / 1,000W bridged mono into 8Ω • 60 amps peak current per channel • 1.3 kVA encapsulated toroid power transformer with 108,000 µF filter capacitance • JFET input stage, MOSFET driver stage, & 16 beta-matched bipolar output transistors • balanced XLR & unbalanced RCA inputs with loop outputs • heavy-duty 24k gold-plated 5-way speaker terminals • brushed silver aluminum chassis with 4U rack-mount kit • showroom verified
Condition: Authorized Showroom Demo • Bench-Tested, Original Packaging, Full Manufacturer Warranty
The Parasound Halo A21+ Stereo Power Amplifier in Silver (Demo) delivers monumental high-current amplification, rich Class A warmth, and iron-fisted bass authority at an exceptional showroom-demo value. Designed by legendary circuit engineer John Curl, this flagship Halo Series two-channel power amplifier outputs a conservative 300 watts per channel into 8 ohms, 500 watts per channel into 4 ohms, and 1,000 watts in bridged mono mode, backed by 60 amps of peak current per channel. Built around a massive 1.3 kVA shielded toroidal transformer with independent secondary windings and 108,000 µF of filter capacitance, this brushed-silver demo unit has been gently auditioned in our climate-controlled reference showroom, thoroughly bench-tested, and includes all original accessories and full Parasound manufacturer warranty protection.
Key Features & Innovations
John Curl High-Bias Class A/AB Circuitry — the Parasound Halo A21+ Stereo Power Amplifier in Silver (Demo) combines matched JFET input stages and MOSFET driver stages with 16 beta-matched 15-amp, 60 MHz bipolar output transistors, operating in pure Class A at normal listening levels before transitioning seamlessly into high-current Class AB.
300W / 500W Stereo & 1,000W Bridged Mono Power — delivers 300 watts RMS per channel into 8 ohms and 500 watts RMS per channel into 4 ohms with both channels driven, effortlessly controlling low-impedance, difficult-to-drive reference floorstanding loudspeakers.
Massive 1.3 kVA Toroidal Power Supply & 60A Peak Current — anchored by a heavy-duty encapsulated 1.3 kVA toroid transformer with separate windings for each channel and 108,000 µF of power supply filter capacitance, generating 60 amps of instantaneous peak current per channel for explosive orchestral and cinematic transients.
Direct-Coupled Signal Path & Balanced XLR / RCA Loop-Outs — eliminates capacitors and inductors from the audio signal path for uncolored harmonic accuracy, offering discrete balanced XLR and gold-plated RCA inputs alongside loop outputs for bi-amping or daisy-chaining multiple amplifiers.
4U Heavy-Duty Brushed Silver Chassis & Custom Protection — finished in classic Parasound brushed silver anodized aluminum with heavy-duty rear carrying handles, custom 5-way speaker binding posts accepting up to 7 AWG wire, DC servo protection, and 12V trigger automation.
FAQ — Parasound Halo A21+ Silver (Demo)
What is the condition and warranty coverage of the Parasound Halo A21+ Stereo Power Amplifier in Silver (Demo)?
The Parasound Halo A21+ Stereo Power Amplifier in Silver (Demo) is a gently auditioned showroom display model in pristine cosmetic and electrical condition; it has passed full bench testing by our technicians, ships in its original double-boxed factory packaging with all accessories, and carries the full Parasound manufacturer warranty.
Can the Halo A21+ drive demanding 4-ohm or electrostatic speakers without strain?
Yes. With 500 watts RMS per channel into 4 ohms, 60 amps of peak current capability per channel, and a damping factor exceeding 1,100 at 20 Hz, the A21+ maintains total control over complex impedance dips in flagship loudspeakers from Bowers & Wilkins, MartinLogan, Magnepan, and Focal.
Can I bridge the A21+ into a 1,000-watt monoblock amplifier?
Yes. A rear-panel Stereo / Bridged Mono switch configures the A21+ as a single 1,000-watt RMS monoblock amplifier into an 8-ohm load, allowing you to pair two units for ultimate dual-mono reference systems.
Does the amplifier include rack-mount hardware?
Yes. Detachable 4U rack-mount ears and hardware are included in the box for custom equipment rack installations, or it can be placed on a standard audio shelf using its vibration-damping isolation feet.
Why Buy From Us
Authorized Parasound reference dealer verifying every showroom demo component for pristine condition and backing it with full factory warranty protection
Experienced two-channel and home theater specialists available to advise on preamplifier gain matching, balanced XLR cabling, and speaker load pairing
Dedicated post-purchase technical support for bridged mono configuration, bi-amping setups, and 12V trigger automation
White-glove, fully insured freight delivery in reinforced heavy-duty double-boxed Parasound packaging on every order
Related & System Matches
Parasound P6 HALO 2.1 Channel Pre-amplifier with Built-in DAC
