Parasound JC 3+ Phono Preamplifier by John Curl Halo

Code: JC 3+

The original Halo JC 3 was designed by legendary audio designer John Curl, and he also did the honors with the JC 3+.

The new model includes a whole raft of improvements over the original, beginning with variable MC load impedance adjustment of 50-550 ohms for each channel using dual gang potentiometers specially made for Parasound by Vishay. This enables precise adjustment to optimize the sound of any MC cartridge. Vishay custom builds these potentiometers for Parasound, and John Curl agreed to adjustable input load only if Parasound used Vishay pots. Getting Vishay to make the pots wasn’t an easy deal. Vishay is a large company, and six months of the JC 3+ development time was spent in negotiations with them to build the custom potentiometers for Parasound. So this is a very big deal indeed.

In StockGET A QUOTE

Description

Features

  • Designed by John Curl – creator of the legendary Vendetta Research phono preamp
  • Inputs and outputs use Vampire brand 24k gold-plated RCA jacks
  • Balanced outputs use Neutrik brand premium XLR jacks
  • MM 47k ohm, MC 47k ohm or MC variable 50-550 Ohms
  • RIAA accurate within 0.2 dB
  • Exclusively Vishay-Dale resistors in the audio path
  • Triple shielding; low-carbon mild steel partitions isolate the power supplies & AC wires
  • Dual mono design; each audio channel is separately enclosed in its own extruded aluminum enclosure
  • Separate high speed-soft recovery rectifiers, filter caps and voltage regulators for each channel
  • Mono switch can improve sound of mono and older LPs
  • Built-in AC line conditioner to prevent AC noise from polluting the circuits
  • AC polarity reverse switch can reduce hum in many systems
  • Non-magnetic aluminum rear panel for purest sound
  • Turn On Options switch: manual or auto with 12v trigger input
  • Premium detachable heavy gauge IEC AC cord
  • 2u Chassis, rack mountable with HRA2 (sold separately)

How the JC 3+ improves on the original JC 3:

  • Variable MC load adjust independent for each channel from 50-550 ohms with dual gang potentiometers specially made for Parasound by Vishay.
  • Curl-Thompson tweaked circuits to further reduce the JC 3 silent background noise.
  • 24k gold plated copper traces on phono module boards for utmost conductivity and most transparency/detail in the music.
  • 47% larger low ESD power supply filter caps greater reserve for head-snapping dynamics.
  • Ability to turn off illumination of the front panel P logo.
  • Now Available in Silver or Black.

Specifications

Frequency Response
20 Hz – 20 kHz, +/- 0.2 dB

Total Harmonic Distortion
< 0.01% at 1 kHz

Signal to Noise Ratio, MM
> 87 dB, input shorted, IHF A-weighted
> 78 dB, input shorted, unweighted

Signal to Noise Ratio, MC
> 87 dB, input shorted, IHF A-weighted
> 67 dB, input shorted, unweighted

Interchannel Crosstalk 
72 dB at 1 kHz

Input Impedance
MM: 47k Ω
MC: 50 – 550 Ω variable, 47k Ω fixed

Output Impedance 
Unbalanced: < 100 Ω
Balanced: < 100 Ω per leg

Input Capacitance
150 pF

Input Sensitivity at 1 kHz 
MM: 4mV for 1 V output
MC: 600µV for 1 V output

Total Gain 
MM: 48 dB
MC: 64 dB

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

AC Power Requirement
Standby: 1 watt
Power On: 12 watts
115 or 230 VAC 50 – 60 Hz
(Selected on Chassis Bottom)

Dimensions
Width: 17-1/4″ (437mm)
Depth: 13-3/4″ (350mm)
Height, with feet: 4-1/8″ (105mm)
Height, without feet: 3-1/2″ (89mm)

Weight
Net: 19 lbs. (8.6 Kg)
Shipping: 26 lbs. (11.8 Kg)

Rack Mount Accessory
HRA 2 (may be purchased separately)