Description
Fosi Audio GR70 Tube Headphone Amplifier
Experience rich, warm, and detailed sound with the Fosi Audio GR70 Tube Headphone Amplifier
A compact Class-A tube headphone amplifier and preamp, perfect for your desktop HiFi setup. Whether you’re pairing it with headphones or speakers, the GR70 offers flexibility, style, and outstanding sonic performance.
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Features
- 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 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;
- 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.
FAQs
- Does the GR70 come with a black knob? Are other colors available? The GR70 comes with a black knob by default. Orange knobs are available for separate purchase.
- GR70 acting as both a preamp and headphone amplifier, do the tone controls work in both cases? Yes, the tone controls work in both scenarios.
- Can the GR70 function simultaneously as a headphone amplifier and preamp? Yes, the GR70 supports simultaneous audio signal output through both the headphone jacks and RCA port. However, for optimal listening experience, we recommend selecting only one output at a time during use.
- How to choose the appropriate impedance mode? The low impedance mode is suitable for headphones ranging from 32Ω to 120Ω, while the high impedance mode is suitable for headphones from 120Ω to 300Ω. Please verify the impedance of your headphones and select the corresponding mode accordingly.
- What type of tube amplifier is the GR70? The GR70 is an OTL (Output Transformer-Less) tube amplifier.
- What are the dimensions of the GR70 unit? The Fosi Audio GR70 measures 187 × 129 × 42 mm (W × D × H).
- How do I adjust the bass and treble on the GR70? Start by setting the bass and treble knobs to the center (neutral) position. Then adjust based on your listening preferences and the characteristics of your headphones or speakers.
What‘s in the box
- GR70 Main Unit *1
- 6Ж4 Vacuum Tubes *2
- 5654 Vacuum Tubes *2
- Tube Protection Covers *2
- 12V/3A Power Supply *1
- User Manual
