John Curlâs symmetrical circuits are well-respected and give the listener the best chance to experience the full emotional content of the source. In the JC 2 the physical implementation of the circuits closely follows the circuit topology and the layout is as literal as possible, commensurate with isolation of disparate or out-of-phase signals. All component parts are oriented for minimum interaction. The high current, low impedance audio power supply is larger than many ampliï¬ers and carefully integrated with the signal boards. The resulting musical output blooms with both absolute musical authority and clarity.
The chassis and PCB layout of the JC 2 are uncompromised in their pursuit of the highest design goals for a preampliï¬er. The shortest signal path is achieved by placing the master volume control and individual channel level potentiometers and high quality gold-plated input select relays right where the input circuitry is located to eliminate the need for long wires and traces. Each channel is on a separate PCB. The preservation of low level signals is achieved by the separation of critical audio signals from non-audio circuits. The audio power supply, control power supply and control circuits also have dedicated PCBs. To prevent the possibility of radiated noise getting into an audio circuit the power supplies and control functions are further isolated from each other by two 3/8 inch thick aluminum partitions that are the full height of the chassis and run side-to-side and front-to-back. The entire signal path is embedded on circuit boards in a continuous ground plane or carried in professional-grade Canare shielded wires.
Even within the audio circuitâs power supply section, AC power is isolated from regulated power by placing the power transformer high in the chassis on one of the aluminum partitions. The power transformer is an R-core type, which has the advantage of a toroid transformer for minimizing radiated hum but is superior at preventing noise carried on the AC power line from passing into its secondary windings. Ground return paths are low resistance, with substantial planes and thick wires, and sequenced precisely. Non-audio control circuitry, LEDs, relay coils and the motor for the master volume control are powered by a separate power supply whose transformer has a separate ground return. The resulting extremely low noise levels enable musical nuances to overlay an utterly silent background.
Home theater bypass enables seamless blending into a digital surround system Home theater bypass functions with both unbalanced & balanced inputs and outputs Home theater bypass function can be assigned to any input Bypass remains selected after unit has been turned off Improved remote control is included with the bypass assignment keys Specifications and sonic performance are 100% the same as the original JC 2 6 pairs unbalanced RCA line-level audio input jacks 2 input pairs can be switched to XLR balanced connectors Independent balanced/unbalanced select for the L & R channel Each channelâs input is switched by its own gold-on-silver contact relay 4 output jack pairs with specialized functions: 1 Main output jack pair is balanced XLR, polarity is switched by remote 1 Main output jack pair is unbalanced RCA, polarity is switched by remote 1 output jack pair is unbalanced RCA, inverted polarity only 1 output pair is unbalanced RCA, normal polarity, fixed level for recorders Dual-mono left & right channel circuit boards minimize crosstalk Hand-matched complementary FETs Direct DC servo-coupled, no capacitors in the signal path Premium 4-gang motor-driven analog master volume control Separate TKD brand analog gain controls for L & R channel 3/8" thick aluminum shielding around audio boards Shielding prevents noise from power supplies & control circuits Separate output jacks for simultaneous normal & non-inverting polarity Aluminum chassis rear panel Remote control polarity switching uses gold-on-silver contact relays Vampire brand 24k gold-plated RCA jacks Neutrik brand premium XLR connectors Canare brand internal wiring High capacity R-core audio power transformer & inductor Hyper-fast soft recovery audio bridge rectifiers diodes Independent power supply for controller, relay coils, triggers, LEDs Remote control handset controls all functions Discrete IR codes for remote control Four 12v trigger output jacks for power amp auto turn-on: Two 12v trigger jacks are switched by the remote handset Two 12v trigger jacks are live when the JC 2 is turned on Two-way RS-232 serial port connection Line level inputs only; no inputs for phono Audio mute is switched by independent L & R relays Rear panel IR repeater input & loop out jacks Premium detachable heavy gauge IEC AC cord 2 6â (2m) trigger wires included Remote handset also controls Parasound Halo T 3 Tuner 3u Chassis, rack mountable with HRA3 (sold separately) Parasound 5 year parts, 5 years labor warranty (For USA and Canada purchases only)
Stereophile, March 2008
POSITIVE FEEDBACK ONLINE - ISSUE 34 (Max Dudious)
Read reviews for all of the Halo line.
Frequency Response 5 Hz - 100 kHz, +0/-3 dB Distortion THD: < 0.003% at 100 Hz THD: < 0.005% at 20 kHz IM: < 0.003% S/N Ratio > 116 dB, input shorted, IHF A-weighted > 104 dB, input shorted, unweighted Crosstalk > 100 dB at 10 kHz > 90 dB at 20 kHz Gain 14 dB, maximum L, R Gain Control Range - 10 dB Input Impedance Unbalanced: 30k ohms Balanced: 30k ohms per leg Output Impedance Unbalanced: < 60 ohms Balanced: < 60 ohms per leg Input Sensitivity 200 mV for 1 V output Total Gain: 14 dB Maximum Output: 8 V XLR Pin Identification 1 = Ground (Shield) 2 = Positive 3 = Negative (Return) AC Power Requirement 110 - 120 V or 220-240 V, 50 - 60 Hzs (Set AC Voltage switch on rear panel) 25 watt standby; 30 watts when turned on Dimensions Width: 17 1/4" (437 mm) Depth: 16" (406 mm) Height, with feet: 5 7/8" (150 mm) Height, without feet: 5 1/4" (133 mm) Weight Net: 24 lbs. (11 kg) Shipping: 36 lbs. (16.4 kg) Rack Mount Accessory HRA 3 (May be purchased separately)