Parasound Halo JC 1+ Reference Mono Power Amplifier (450 Watts)

Changes from the JC 1 to JC 1+

Read the JC 1+ development story here

• 400 → 450 Watts @ 8Ω
• 800 → 850 Watts @ 4Ω
• 1200 → 1300 Watts @ 2Ω
• Filter capacitance: 132,000 → 198,000 uF
• Transformer capacity: 1.9 → 2.1 kVA
• Output transistors: 18 → 24 Sanken 60Mz devices
• Peak current: 135 → 180 amps
• Weight: 64 → 83 lbs net
• Bybee Music Rails™ active high frequency noise filters
• John Curl driver stage employs a new cascode circuit design
• FR-408 input circuit board material improves HF signal integrity
• Gain switch to select 29 dB or 23 dB of gain
• R-core power transformer for input stage
• Input circuit board is shielded
• Double thickness copper on output/power supply circuit boards
• Gold-plated internal audio signal path connectors
• Custom CHK Infinium speaker binding posts
• Looping Neutrik XLR output for easier bi-amping
• Front panel power indicator LED
• Updated auto turn on circuits with 3.5mm 12V trigger jacks

All Features:

• Circuitry designed by legendary John Curl
• Ultra-high bias Class A/AB operation
• 25 watts of pure Class A power
• Stable with speaker impedance dips below 1Ω
• Bybee Music Rails™ - active high frequency filters for input stage
• New John Curl driver stage employs a cascode circuit for greater open loop bandwidth & superior linearity
• Gain switch to select 29 dB or 23 dB gain for optimum compatibility with high gain preamps or extremely efficient speakers
• R-core transformer for input stage suppresses noise on power line
• 6 massive 33,000 uF Nichicon Gold Tune filter capacitors for output stage
• 22,400 uF input stage power supply filter capacitors, independent of the main power supply
• Dual CHK Infinium, custom 5-way speaker binding posts for easy bi-wiring
• Neutrik locking XLR balanced input & loop output jacks
• Vampire 24k gold-plated RCA input & loop output jacks
• Direct-coupled signal path, no capacitors or inductors in the audio path
• JFET input stage, MOSFET driver stage
• 24 beta-matched 15 ampere, 230V, 60 MHz bipolar output transistors
• 2.1 kVA shielded toroid power transformer with premium H18 grade core
• Independent power supplies for input stage, driver stage & output stage
• Full power is rated all the way down to 2Hz for unrestricted low-end bass
• Harris hyper-fast soft-recovery bridge diode rectifiers
• REL & Nichicon Muse capacitors
• DC servo & 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 is included
• Available in silver or black

Power Output 
450 x1 watts @ 8 Ω 
850 x1 watts @ 4 Ω 
1300 x1 watts @ 2 Ω

Power measurements are with 120 VAC: 
0.15% THD, RMS continuous power, 
full audio band (20 Hz - 20 kHz)

Class A Power Output 
25 Watts, bias switch set to high 
10 Watts, bias switch set to low

Current Capacity 
180 amps, peak

Slew Rate > 130 volts per microsecond

Frequency Response 
2 Hz - 120 kHz, +0/-2 dB 
20 Hz - 20 kHz, +0/-0.25 dB

Total Harmonic Distortion (THD) 
< 0.15 % at full power 
< 0.02 % at typical listening levels

IM Distortion 
< 0.03 %

TIM 
Unmeasurable

Damping Factor 
> 1200 at 20 Hz

Input Impedance 
Unbalanced: 50 kΩ 
Balanced: 100 kΩ, (50 kΩ per leg)

S/N Ratio, inputs shorted 
>122 dB, IHF A-weighted, bias set to Low 
>120 dB, IHF A-weighted, bias set to High 
>113 dB, Unweighted, bias set to Low 
>111 dB, Unweighted, bias set to High

Total Gain 
29 dB (Gain switch set to normal) 
23 dB (Gain switch set to low)

Input Sensitivity for 28.28 V Output into 8 Ω 
Unbalanced: 1 V 
Balanced: 1 V per leg 
(Gain switch set to normal)

DC Trigger Requirements 
+9 Vdc to +12 Vdc, 5 mA

Audio Trigger Requirement 
2.5 mV - 10 mV

XLR Pin Identification 
1 = Ground (Shield) 
2 = Positive 
3 = Negative (Return)

Dimensions 
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)

Shipping Carton Dimensions 
Width: 29-1/2" (750 mm) 
Depth: 27-1/2" (700 mm) 
Height: 15-3/4" (400 mm)

Net Weight 
83 lb. (37.6 kg)

Shipping Weight 
107 lb. (48.5 kg)

Power Requirement 
Standby: <1 Watt 
Idle (bias set to low): 145 Watts 
Idle (bias set to high): 275 Watts 
Typical Listening levels: 400 Watts 
Maximum: 1500 Watts

Stereophile (John Atkinson), May 2020 
"With JC 1+ amplifiers, the feeling of listening to a Steinway D in a real space was very satisfying. High frequencies were smooth and clean, more like what I experience from a good tube amplifier. Dynamics were extraordinary. Low-frequency power and delicacy! The improvement in its sound quality and the recent explosion of the prices of high-end, high-power amplifiers keep the JC 1+ competitive. This is a superb-sounding amplifier that will get the best from every loudspeaker with which it is partnered. Well done, Mr. Curl." 
Manufacture Comments to the Stereophile Review

Secrets of Home Theater & High Fidelity (John Johnson), June 2020 
"Parasound has long been admired for their preamplifiers and power amplifiers. The JC 1+ power amplifier is truly an achievement to the highest degree. The sound is exemplary and reflects its amazing design, while parts quality is a statement on its own. Proof of Performance for the Parasound has been verified. They are worth the price."

Positive Feedback May 2020 
"I cannot think of a pair of monoblocks that offer a view anywhere near this close to the top of the heap for anywhere near their asking price. I can tell you that if I were shopping for a pair of monoblocks under $25,000, the Parasound Halo JC 1+ would be my first choice. Go give these new over-achievers a listen and be prepared to be bowled over by what you will hear. Most enthusiastically recommended."