Compact HiFi Tube Headphone Amplifier for Audiophile Listening

The Fosi Audio P2 Headphone Amplifier is a compact desktop HiFi tube headphone amplifier and stereo preamp designed for audiophiles who want warm analog sound, low-noise performance, and premium headphone amplification in a minimalist desktop setup.

Featuring dual 5725 vacuum tubes, the reliable NE5532 op-amp, RCA and 3.5mm stereo inputs, and support for headphones up to 600Ω impedance, the P2 delivers smooth, rich, and immersive sound for both casual and critical listening. Its all-aluminum alloy chassis and tube rolling compatibility make it an excellent entry-level tube amplifier for music lovers and headphone enthusiasts.

Perfect for desktop HiFi systems, audiophile headphones, music streaming, gaming, and personal listening setups.

Warm Vacuum Tube Audio with Audiophile Tuning

The P2 combines classic vacuum tube sound with modern low-noise audio engineering for a musical and fatigue-free listening experience.

Included Tubes:

• 2 × 5725 Vacuum Tubes

Tube Sound Benefits:

• Warm analog tonality
• Smooth vocals
• Rich midrange texture
• Softer treble response
• Relaxed listening presentation

Designed for audiophiles seeking:

• More musical sound
• Improved vocal richness
• Natural instrument timbre
• Tube-enhanced listening

The P2 creates a more organic sound signature compared to standard solid-state headphone amplifiers.

Powerful Headphone Amplification

The P2 is engineered to drive a wide range of headphones, including demanding audiophile models.

Supported Headphone Impedance:

• 32Ω–600Ω

Compatible Headphones:

• Sennheiser HD580
• Sennheiser HD600
• Sennheiser HD650
• AKG K701
• AKG K702
• AKG Q701
• Many other audiophile headphones

This dedicated amplification stage improves:

• Dynamic range
• Bass control
• Volume headroom
• Instrument separation
• Overall listening immersion

Ideal for:

• Over-ear headphones
• Studio headphones
• Audiophile listening
• Desktop music systems

Stereo Preamp Functionality

The P2 is not only a headphone amplifier but also functions as a stereo preamplifier for home audio systems.

Input Options:

• 3.5mm Audio Input
• Stereo RCA Input

Output:

• 6.35mm Headphone Output

Included:

• 6.35mm to 3.5mm adapter

The versatile connectivity makes the P2 compatible with:

• PCs and laptops
• DACs
• Smartphones
• CD players
• Audio streamers
• Desktop audio systems

Perfect for compact HiFi setups and personal audio systems.

Tube Rolling for Sound Customization

The P2 supports a wide range of compatible vacuum tubes, allowing users to personalize their listening experience.

Compatible Tube Types:

• JAN 5654W
• 6J1
• 6J4
• GE5654
• 6AK5
• 6*1n
• E180F
• 6ж9П
• EF861
• 6688

Tube rolling allows:

• Different tonal characteristics
• Warmer or brighter sound tuning
• Personalized sound profiles
• DIY audiophile experimentation

Perfect for tube audio enthusiasts.

Low-Noise HiFi Audio Circuit Design

The P2 is optimized for clean and stable audio playback with minimal background noise.

Audio Performance:

• THD: ≤0.03%
• SNR: ≥95dB
• Frequency Response: 20Hz–20kHz (±3dB)

Built-In Protection:

• Output protection circuitry
• Low ground noise design
• Safe operation for premium headphones

This ensures:

• Clean signal amplification
• Low distortion playback
• Quiet background performance
• Smooth listening experience

Premium Compact Aluminum Design

The P2 features a durable all-aluminum alloy enclosure with a compact desktop-friendly footprint.

Design Features:

• CNC aluminum alloy shell
• Compact minimalist chassis
• Lightweight construction
• Visible vacuum tube design
• Desktop-friendly size

Perfect for:

• Desktop audio systems
• Small HiFi setups
• Office listening stations
• Minimalist workspaces

Technical Specifications

• Model: P2
• Product Type: Tube Headphone Amplifier & Stereo Preamp
• Op-Amp:
  • NE5532
• Vacuum Tubes:
  • 2 × 5725
• Inputs:
  • 3.5mm Audio Input
  • Stereo RCA Input
• Outputs:
  • 6.35mm Headphone Output
• Headphone Output:
  • 16Ω–64Ω
• Supported Headphone Impedance:
  • 32Ω–600Ω
• Frequency Response:
  • 20Hz–20kHz (±3dB)
• THD:
  • ≤0.03%
• Signal-to-Noise Ratio:
  • ≥95dB
• Input Sensitivity:
  • 0.2mV
• Operating Voltage:
  • DC 12V
• Dimensions:
  • 99 × 98 × 33mm
• Weight:
  • 0.25kg

Key Features

• HiFi tube headphone amplifier
• Dual 5725 vacuum tubes
• Stereo preamp functionality
• Supports 32Ω–600Ω headphones
• Tube rolling compatibility
• NE5532 audio op-amp
• Low-noise audio circuit
• Compact aluminum chassis
• RCA and 3.5mm inputs
• Warm analog-style sound