X4 vs Music Hall Mini
The Mini's signal-to-noise is 80 dB against the X4's 70 dB, its mm gain 42 dB against 40 dB, its thd 0.020% against 0.100%, and its output voltage 0.6V RMS against 0.7V RMS.
AI-generated product photo — not official manufacturer imagery.
AmplifiersPhono Pre-AmpsHeadphone Amplifiers
Estimated price (community-sourced)
$43
Around — community and catalog average, updates slowly
About the X4
The Fosi Audio BOX X4 (often listed as Fosi Audio X4) is a compact, two-channel hybrid tube phono preamplifier and headphone amplifier for moving-magnet (MM) turntables. It uses two JAN 5654W vacuum tubes and includes volume, bass, and treble controls. The unit accepts an MM phono source or a 3.5 mm AUX source, and provides an RCA line output for powered speakers or a separate amplifier plus a 3.5 mm headphone output. It is a preamplifier rather than a power amplifier, so it cannot directly drive passive speakers. The product is still listed by Fosi Audio and multiple retailers; therefore, it does not appear to be discontinued.
Specifications
Analog Output
Analog signal output specifications
- THD
- 0.100%
- SNR
- 70 dB
- Output Voltage
- 0.7V RMS
Phono Preamplifier
Phono stage specifications
- MM Gain
- 40 dB
- Adjustable Loading
- No
- Loading Options
- 47000Ω
- Adjustable Capacitance
- No
Connectivity
Input and output connections
- Analog Inputs
- MM phono input via RCA, 3.5 mm AUX analog input
- Analog Outputs
- stereo RCA line/preamp output, 3.5 mm headphone output
Physical Dimensions
Size, weight, and appearance
- Dimensions
- 120 × 35 × 101 mm (W × H × D)
- Weight
- 0.34 kg (1 lbs)
- Available Colors
- black
Specifications are community-contributed and may not be accurate or complete. Verify all details with the manufacturer before making purchasing decisions. Terms & Conditions