Parasound Halo JC1+ Mono Power Amplifier

A 450 W, ultra-high-bias class A and AB amp designed by John Curl.

With circuitry designed by the legendary John Curl, the flagship Parasound Halo JC1+ is a world-class reference quality power amp. It offers 25 W of class-A power before switching (if ever needed) into class AB operation. A new John Curl driver stage employs a cascode circuit for greater open-loop bandwidth and superior linearity.

The Upscale View

Parasound is one of the industry's low-key, high-return brands. It's not always the first name on a customer's lips, yet is a hugely respected and loved brand by people who work in high-end audio. This isn't just because of the legendary John Curl who is behind most of its top-flight designs, but also because Parasound uses such expensive and solid engineering, yet is able to price its products so reasonably. Parasound is the brand of choice for someone who really knows good sound, but doesn't have the budget for audio jewellery.

The JC series of amps are extra special because they use John Curl's innovative designs that offer elaborate noise control and protection, but are extremely straightforward from the signal's point of view.  The result is dynamic, high power with grace, musicality, detail, and ease. This is extremely difficult to pull off, but John Curl and Parasound have done it. 

Noise Suppression

Parasound uses a very special kind of power supply rail in its input stage called Bybee Music Rails. Noise on the input stage is going to be amplified and affect everything in the signal chain after it, so it's essential that an amp's input stage be as quiet as possible. The Bybee rails offer active high-frequency filtration for the input stage, greatly dropping noise issues early in the amplifcation process. .Gain can be set to 29 dB or 23 dB gain for optimum compatibility with high-gain preamps or extremely efficient speakers.

In addition to special rails, a separate R-core transformer for the input stage suppresses noise on the power line. The 22,400 uF input stage power supply filter capacitors are independent of the main power supply. These smooth out the current and also offer a reservoir of current for rapid transients, greatly improving dynamics.

The output stage in turn has six massive 33,000 uF Nichicon Gold Tune filter capacitors, ensuring that all ripple and other issues are smoothed out long before they can corrupt the signal.

Direct Connections, Great Power

The JC1+ uses a direct coupled signal path, which means that no capacitors or inductors get in the way of great sound. The JFET input stage is connected to a MOSFET driver stage, and the amp uses 24 beta-matched 15 ampere, 60 MHz bipolar output transistors. All this means lightning fast response but also excellent linearity and low noise. 

The 83 lb. amp uses a 2.1 kVA shielded toroidal transformer with a premium H18 grade core. There are independent power supplies for the input, driver, and output stages. The output stage uses Harris hyper-fast soft-recovery bridge diode rectifiers and REL & Nichicon Muse capacitors continue the theme of expensive, overspecified design that results in a sound with huge power and headroom. Full power is rated all the way down to 2 Hz for unrestricted low-end bass

The result is a power amp that can deliver 450 W into 8 ohms, and 850 W into 4 ohms. Your speakers are protected from runaway issues with DC servo and relay based protection circuits.

Features

• DC Servo and relay protection circuits
• AC turn-on inrush surge protection with relay bypass
• Automatic turn-on by 12 V trigger or audio sensing
• 4 rack space chassis with rear carry handles
• Rack mount hardware included

Specifications

Power Output (8, 4, 2 Ohm): 450 W, 850 W, 1,300 W

Inputs: Stereo RCA, stereo XLR, DC trigger

Input Impedance: 100 kΩ

Gain: 23, 29 dB

Dimensions (WHD): 17-5/8" x 7-1/8" x 20"

Weight: 83 lb.