Fosi Audio Fosi Audio GR70 Tube Headphone Amp

• Pure Tube Amplification
• Adjustable Impedance and bass & treble Control
• 2-in-1 Headphone Amp and Preamp
• Supports 16–300Ω Headphone Impedance

GR70 Vacuum Tube Headphone Amp

Featuring two replaceable 5654W and two 6Ж4/6Ж8 vacuum tubes, it offers a customizable auditory experience. Immerse yourself in the authentic warmth and smoothness of analog audio.

Integrating Vintage Charm with Modern Precision

The GR70 is a two-in-one headphone amp and preamp. Easily integrate this tube preamp into your home audio system with its multiple headphone jacks and RCA input/output options.

• Input: RCA; Output: RCA, 6.35mm/3.5mm Headphone Output;
• Rated Power Output: 90mW@32Ω; Max Power Output: 300mW@32Ω; Power Input: DC 12V/3A;
• Headphone Impedance: Low Mode: 16Ω-120Ω, High Mode: 120Ω-300Ω;

Quad-Tube Dual-Stage Amplification

Thoughtfully selected tube combination for a musical and immersive sound.

Ideal for Headphone Enthusiasts

It pairs excellently with over-ear and in-ear headphones for superior audio.

Ideal Partner to V3 & Q6

It pairs perfectly with power amps and passive speakers for a top-notch audio setup.

Customize Your Unique Sound

With central detents to easily restore the natural sound.

Large Top-Mounted Volume Knob

Built-in precision damped potentiometer for smooth, accurate control.

Switchable Output Impedance

Ensuring optimal control and cleaner sound across a wide range of full-size cans and IEMs.

Efficient Cooling and Thermal Stability

Keeps dust out while maintaining airflow to protect internal components.

A Blend of Metal and Elegance

Full aluminum alloy body, finely sandblasted, featuring a minimalist and durable design.

• Pure Tube-Amplification: The GR70 headphone tube amp combines vintage charm with modern tech, delivering authentic tube essence. Perfect for headphone enthusiasts, it pairs excellently with over-ear and in-ear headphones for superior audio
• Quad Tubes: Features two 5654W and two 6Ж4/6Ж8 vacuum tubes for two-stage amplification. The 5654W tubes boost voltage, while the 6Ж4/6Ж8 tubes handle power amplification. This setup delivers balanced, transparent, and textured sound
• User-Friendly Design: This tube headphone amp preamplifier offers intuitive controls, including a large volume knob, dual-side ventilation holes, bass & treble controls, high and low impedance mode switching, making it versatile enough
• Two-in-One: It supports low and high impedance modes switching to adapt 16Ω-300Ω headphones, and features 6.35mm/3.5mm headphone jacks on the front and RCA Input/Output on the rear for home audio HiFi system integration
• Compact Yet Powerful: Crafted with a CNC-machined aluminum alloy body, the GR70 is both durable and refined. Despite its compact size, it delivers up to 300mW power output and 1.2V RCA output with SNR ≥97dB—offering warm, clean, and dynamic sound

• GR70 Main Unit *1
• 6Ж4/6Ж8 Vacuum Tubes *2
• 5654 Vacuum Tubes *2
• Tube Protection Covers *2
• 12V/3A Power Supply *1
• User Manual