Fosi Audio GR70 Tube Headphone Amp

China flag
Fosi Audio Fosi Audio GR70 Tube Headphone Amp #1
Fosi Audio Fosi Audio GR70 Tube Headphone Amp variant 1
Fosi Audio Fosi Audio GR70 Tube Headphone Amp variant 2
Fosi Audio Fosi Audio GR70 Tube Headphone Amp variant 3
Fosi Audio Fosi Audio GR70 Tube Headphone Amp variant 4
Fosi Audio Fosi Audio GR70 Tube Headphone Amp variant 5
Fosi Audio Fosi Audio GR70 Tube Headphone Amp variant 6
Fosi Audio Fosi Audio GR70 Tube Headphone Amp variant 7
Fosi Audio Fosi Audio GR70 Tube Headphone Amp variant 8
Fosi Audio Fosi Audio GR70 Tube Headphone Amp variant 9

Fosi Audio Fosi Audio GR70 Tube Headphone Amp

View at Fosi Audio
Tone Controls
Pre-Out
  • 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 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;
  • 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 vacuum tubes for two-stage amplification. The 5654W tubes boost voltage, while the 6Ж4 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
  • 6AC7 Vacuum Tubes *2
  • 5654 Vacuum Tubes *2
  • Tube Protection Covers *2
  • 12V/3A Power Supply *1
  • User Manual

FAST, EASY & NEAR

Find Fosi Audio Verified Dealers Near You

Fosi Audio dealers in the map

HiFiGo
Altitudo Audio
Audio Magic - EU
ljudshopen
Hifi Passion
AV Cables
Acoustic Technologies
Audeos
AUDIOPHONICS
Kruunuradio
Audio Domain
Parts Express
The Audio Co.
Nonsolo Speakers

Join us at T.H.E. Vegas 2026!

T.H.E. Show

+

HiFi Hub Logo

Reviews

Online Reviews & Mentions

Forum Mentions

No forum mentions found yet

store
store
store
store
store
store