Fosi Audio Box X4 MM Turntable Phono Preamplifier.

•  The updated version for BOX X2. Next-generation phono preamp for unrivaled sound quality.
• JAN 5654W Tube MM Phono Preamplifier: The BOX X4 phono preamp supports 3.5MM AUX and MM turntable input, converting phono signals to Line Level signals with low-noise integrated circuits and high-quality components to remove low-frequency noise ensure clear sound quality. Designed with a grounding post to protect your turntable.
• Tube Headphone Amplifier & Preamplifier: The BOX X4 is designed with a 3.5MM AUX headphone and RCA output, highly useful beyond imagination.
• Applicable Vacuum Tube Model: 5654W/6K4/6J1/6J4/GE5654/6AK5/66*In vacuum tubes, etc. You can replace the vacuum tubes to DIY your stereo system. Different tubes with different sounds.

• Specifications

  
  
  

  Specifications	Details
  Model	BOX X4
  Applicable headphone types	16 Ω
  Input Mode	MM turntable + 3.5mm AUX
  Output Mode	RCA + 3.5mm headphone output
  Output	Active(powered) speakers, Amplifier, Headphones
  Frequency Response	Standard RIAA
  THD	≤ 0.1%
  SNR	≥ 70dB
  Device Dimension	4.72 x 3.97 x 1.37 inches
  DC Input Range	12V
  Input Voltage Range	AC 110V – 240V
  Output Voltage Level	1kHz and 650mV
  Power Supply	12V 1.5A