Parasound JC-3 Jr. Phono Preamplifier

Hear the dynamics in the groove

Parasound's JC 3 Jr. brings your vinyl to life with warm, articulate — and quiet — signal boosting and equalization. This phono stage offers flexible gain and impedance controls to give you the freedom to experiment with cartridges and get the best out of your favorites. And balanced and unbalanced outputs let you connect to any amplifier or stereo preamp you choose.

Designed to capture detail

With its toroidal transformer, aluminum shielding, and efficient topology, the JC 3 Jr. achieves a very low signal-to-noise ratio. It shares many of the same top-quality components of its bigger brother, the JC 3+ with a recognizably similar open and detailed soundstage. But despite the Jr.'s smaller price and profile, there's no doubt that it punches above its weight.

The legacy of John Curl

The JC 3 Jr. features circuitry designed by by John Curl, a legend in audio engineering. He started his career in the 1970s, designing tape and video recorders at Ampex, and he had a hand in building the Grateful Dead's Wall of Sound. Curl has worked with Parasound since 1989, designing all of their high-power amplifiers and more. The power supply, transistors, capacitors and other parts in the JC 3 Jr. were chosen to offer high performance at a reasonable price.

Product highlights:

• compatible with moving magnet and moving coil phono cartridges
• 3-way cartridge select switch:
• moving magnet: 47k ohm
• moving coil: 47k ohm
• moving coil: variable 50-550 ohms — independent knob adjustment in 10 ohm increments
• 3-way gain select switch
• 40/50/60 dB (when using unbalanced RCA outputs)
• 46/56/66 dB (when using balanced XLR outputs)
• signal-to-noise ratio:
• 40 dB gain setting: 85 dB
• 50 dB gain setting: 89 dB
• 60 dB gain setting: 94 dB
• total harmonic distortion: < 0.02% at 1 kHz
• selectable mono or stereo output
• aluminum shield separates power supply from audio circuits, reducing noise
• shielded toroid power transformer

Connections:

• 1 pair unbalanced RCA inputs
• 1 pair unbalanced RCA outputs
• 1 pair balanced XLR outputs
• 3.5mm 12V trigger input and output jacks

Dimensions and warranty:

• 17-1/4" W x 2-1/2"H x 17"D (1U rack space)
• rack-mountable with the Parasound RMK 11 sold separately
• weight: 13 lbs.
• warranty: 5 years
• MFR # JC3 JR. SILVER

Features & specs

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Features

High-Quality Design: The Parasound JC 3 jr phono preamp features high-quality design and construction to deliver the best possible sound from your vinyl recording. The sensitive phono circuitry is isolated by a thick aluminum partition. This separates critical audio signals from the non-audio circuits and wiring. The JC 3 jr's power supply uses a high capacity toroid power transformer. The transformer is encased in epoxy within a steel enclosure to further reduce any vibration or noise contamination. The JC 3 jr. employs a common mode inductor to reduce noise from the AC power source from coming into the power supply board. The resulting extremely low noise levels enable musical nuances to emerge from an utterly silent background.

MM or MC Compatible: The Parasound JC 3 jr phono preamplifier is compatible with turntables that are equipped with MM (moving magnet) or MC (moving coil) cartridges. There is a switch located at the back panel that allows you to select between MM (47k ohm), MC (variable), or MC (Fixed). The MM setting is fixed at 47,000 ohms, while the MC setting is variable and can be adjusted from 50 to 550 ohms. There is also a MC Fixed setting that provides an alternative fixed 47,000 ohm load for select MC cartridges.

Input Impedance Control: The JC 3 jr's Input Impedance Control enables you to fine tune the input impedance for MC cartridges over a range of 50 ohms to 550 ohms. Cartridge manufacturers recommend what they consider to be an optimal load impedance. However, their spec won't necessarily give you the best results in your system. You should experiment with this control and use whichever load impedance you feel results in the best performance of your system in your listening room.

Gain Control: The Gain Control allows you to select the appropriate gain for your turntable's MM or MC cartridge. Select 40dB, 50dB, or 60dB. Whether you have an MC or MM cartridge you can experiment with which of the three gain settings gives you the best with your line stage preamp or integrated amplifier.

• 40dB: The lowest gain settings that is typically used with moving magnet (MM) cartridges.
• 50dB: For high output moving coil cartridges or low output moving magnet cartridges.
• 60dB: For low output moving coil cartridges whose output is typically less than 0.5mV.

Mono Button: Press the JC 3 jr's Mono button to parallel the left and right stereo channels to mono. Press it again to return to stereo. The Mono button glows blue when stereo is selected and changes to amber when mono is selected. Older mono records and stereo records pressed with high levels of rumble will sound cleaner when you select mono on the JC 3 jr.

Balanced & Unbalanced Connectivity: The Parasound JC 3 jr phono preamplifier is outfitted with both balanced XLR and unbalanced RCA connections. In most systems balanced XLR connections will give you the best sound.

• Unbalanced RCA Inputs: For its analog inputs, the JC 3 jr phono preamplifier is equipped a set of unbalanced stereo RCA inputs. These unbalanced stereo RCA inputs connect to your turntable.
• Balanced XLR and Unbalanced RCA Outputs: For its analog outputs, the JC 3 jr phono preamp is equipped with a set of balanced stereo XLR outputs and a set of unbalanced stereo RCA outputs. These balanced or unbalanced outputs connect to your line-level preamplifier or integrated amplifier. The balanced XLR outputs will provide maximum rejection of external noise sources.

Note: The balanced and unbalanced jacks are active simultaneously, but should not be used at the same time.

Ground Wire: To eliminate hum, your turntable's ground wire attaches to the JC 3 jr's ground terminal that is located on the rear-panel next to the right channel XLR balanced output.

12V In/Out: The Parasound JC 3 jr is equipped with a 12V trigger input (3.5mm) and output (3.5mm). The Trigger In allows the phono preamp to turn on automatically with your preamplifier or integrated amp that features a Trigger Out. The Trigger Out lets you loop or "daisy-chain" the incoming trigger voltage to another component. The JC 3 Jr. trigger circuit draws a negligible 10mA current from the triggering device.