Halo by Parasound® Phono Preamplifier

• Circuitry designed by legendary John Curl
• Circuit board layout by Carl Thompson
• Cartridge options for 47k O 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)

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 O
• MC Variable: 50- 550 O

Output Impedance

• Unbalanced: < 100 O
• Balanced: < 100 O per leg

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

• 115 VAC or 230 VAC 50 - 60 H

Dimensions

• Depth without cables: 14.75
• Height without feet: 1.75

Useful Documents