Parasound Halo JC 3+ Phono Preamplifier by John Curl

Your new Parasound Halo JC 3+ Phono Preamplifier is the pinnacle of analog audio technology and value engineering. It is legendary designer John Curl’s latest phono preamplifier design, continuing his reputation for designing legendary phono preamplifiers that date back to the 1970s.

Design Overview

John Curl’s phono preamps are legendary. His approach to amplifying extremely low level signals gives the listener the best chance to experience the full emotional content of the source. In the JC 3+ the physical implementation of the circuits closely follows the actual circuit topology and the layout is as compact as possible to minimize pickup of external noise. The preservation of low level signals is achieved in several ways.

The phono module circuit boards are 14k gold plated for optimum electron flow. They are further protected by physically separating these critical audio signals from the non-audio circuits and non-audio wiring. Each channel has its own circuit board and each channel is fully enclosed in its own extruded aluminum “vault.” This vault shields the sensitive circuits from the JC 3+’s power supply and from external sources of noise.

The JC 3+ power supply uses a high capacity 1 ampere R-core power transformer. R-core transformers share the advantages of a toroid transformer for minimizing radiated hum. However, it is far superior to a toroid transformer in preventing noise carried on the AC power line from passing through to its secondary windings and into the power supply.

40,000uF of filter capacitance assures you will hear all of the dynamic contrasts that give additional life and presence to your LPs. A second level of shielding separates each phono vault from the power supply, power transformer and even the transformer wires running to the AC inlet on the rear panel. This shielding consists of two partitions of 3/8” low carbon “mild” steel to prevent any electromagnetic radiation from reaching the phono modules.

The rear panel of the JC 3+ is made of aluminum to prevent any electromagnetic interaction with the sensitive phono circuitry. The JC 3+ has an on-board AC line conditioner to filter out high frequency noise and distortion that may be present on your AC power line. This eliminates a potential source of noise before it ever reaches the JC 3+ power transformer. The resulting extremely low noise levels enable musical nuances to emerge from an utterly silent background.