The JC3 Jr. Phono preamplifier is an amazing sounding product with desirable features including MM and MC cartridge options, gain and impedance adjustment and balanced or unbalanced output.
- Circuitry designed by legendary John Curl
- Circuit board layout by Carl Thompson
- Cartridge options for 47k Ω MM and MC/MI
- Variable MC impedance adjustment of 50-550 ohms
- Gain select for 40 dB/50 dB/60 dB unbalanced (46 dB/56 dB/66 dB balanced)
- Balanced and unbalanced outputs
- Mono switch can improve sound of mono & older LPs
- Convenient auto turn-on by 12V trigger
- RIAA accurate to within 0.2 dB
- Incredible S/N up to 94 dB and THD less than 0.02%
- Vishay-Dale resistors in the audio path
- Aluminum shield separates power supply and audio circuits
- Shielded toroid power transformer
- High speed-soft recovery bridge rectifiers and common mode inductors
- Vampire brand 24k gold-plated RCA jacks
- Neutrik brand locking balanced XLR outputs connectors
- Compact 1U chassis (2.5" high with feet)
- Available in silver or black
Specs
Frequency Response:
20-20Khz, +/- 0.2dB
Total Harmonic Distortion
< 0.02% at 1 kHz
Signal to Noise Ratio, 40 dB Setting
>85dB, input shorted, IHF A-weighted
>80dB, input shorted, unweighted
Signal to Noise Ratio, 50 dB Setting
>89dB, input shorted, IHF A-weighted
>84dB, input shorted unweighted
Signal to Noise Ratio, 60 dB Setting
> 94dB, input shorted, IHF A-weighted
> 91dB, input shorted, unweighted
Inter-channel Crosstalk
>80 dB at 1 kHz
Input Impedance
MM or MI: 47k Ω
MC Variable: 50- 550 Ω
Output Impedance
Unbalanced: < 100 Ω
Balanced: < 100 Ω per leg
Input Capacitance
150 pF
Input Sensitivity at 1 kHz, 4mV Input
40 dB: 4 mV for 450mV output
50 dB: 4 mV for 1.4 Volts output
60 dB: 4 mV for 4.25 Volts output
Input Sensitivity at 1 kHz, 1V Output
40 dB: 9 mV for 1.0 Volt output
50 dB: 3 mV for 1.0 Volt output
60 dB: 0.9 mV for 1.0 Volt output
Total Gain
40 dB / 50 dB / 60 dB (unbalanced output)
46 dB / 56 dB / 66 dB (balanced output)
XLR Pin Identification
1 = Ground (Shield)
2 = Positive
3 = Negative (Return)
AC Power Requirement
Standby: <1 watt
Power On: 9 watts
115 VAC or 230 VAC 50 - 60 Hz
Dimensions
Width: 17-1/4” (437mm)
Depth: 14-3/4” (375mm)
Depth with cables: 17” (432mm)
Height: 2-1/2” (63.5mm)
Height, without feet: 1-3/4” (45mm)
Weight
Net: 13 lbs. (5.9 Kg)
Shipping: 19 lbs. (8.6 kg)