Parasound Halo JC 3+ Brochure & Specs

Halo JC 3+ Phono Preamplifier
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A new improved version of our award-winning JC 3
Six years ago we asked legendary audio designer John Curl if he would create a reasonably priced Parasound
Halo phono preamplifier in the spirit of his masterpiece, the Vendetta. Three years later we introduced the
remarkable Parasound Halo JC 3 which has earned rave reviews from the audiophile press and a legion of
vinyl enthusiasts. During the design phase of the original JC 3, Curl had rejected variable load adjustment
because potentiometers generally have higher thermal self-noise, which is an anathema to the creation of
an ultra low noise phono stage. Our decision to bring the JC 3 to market with limited switched input load
impedance choices disappointed some vinyl enthusiasts who consider input load fine-tuning to be essential
for certain cartridges.
Curl and circuit board designer Carl Thompson eventually consented to a redesign with variable load
impedance adjustments, but with these caveats for the potentiometers: 1) They must comply with stringent
performance requirements. 2) They must be manufactured by Vishay, a highly-regarded manufacturer of
low-noise component parts.
We took this opportunity to make additional performance improvements. Curl has narrowed the spectrum
of Johnson/Nyquist noise in the resistor that loads the input stage. Circuit-board designer Carl Thompson
tweaked the phono module board layouts to further optimize every performance parameter. The phono
modules copper circuit board traces now have 24 karat gold-plating where each part is soldered to provide
exceptional transparency and musical detail.
As a result of these changes, the MC signal to noise ratio is improved to 87dB, A-weighted. MM gain has
been increased slightly to 48dB, while MC gain has been lowered from 68dB to 64dB so that extra-high
output MC cartridges won’t cause the JC 3+ to overload the inputs of some line stage preamps or integrated
amps.
The JC 3+ power supply has also been significantly upgraded with 47 percent larger low-ESD power supply
filter capacitors and an 82 percent larger R-core power transformer. This provides much greater current
reserves for head-snapping dynamics. Finally, we added an on/off switch for the front P logo illumination.

Parasound Halo JC 3+ Specifications

Frequency Response and Distortion

frequency response	20 Hz – 20 kHz, +/- 0.2 dB
total harmonic distortion	< 0.01% at 1 kHz

Signal to Noise Ratio

signal to noise ratio, MM, IHF A-weighted	87 dB
signal to noise ratio, MM, unweighted	78 dB
signal to noise ratio, MC, IHF A-weighted	87 dB
signal to noise ratio, MC, unweighted	67 dB

Power Requirements

power on consumption	12 watts
standby power consumption	1 watt
AC power requirement	115 or 230 VAC 50 - 60 Hz

Input and Output Impedance

input impedance, MM	47k Ω
input impedance, MC	50 – 550 Ω variable, 47k Ω fixed
output impedance, unbalanced	< 100 Ω
output impedance, balanced	< 100 Ω per leg

Gain and Sensitivity

total gain, MM	48 dB
total gain, MC	64 dB
input sensitivity at 1 kHz, MM	4mV for 1 V output
input sensitivity at 1 kHz, MC	600µV for 1 V output

Weight and 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)
net weight	19 lbs. (8.6 Kg)
shipping weight	26 lbs. (11.8 Kg)