Fosi Audio GR70 Tube Headphone Amplifier

Fosi Audio GR70 Stereo Tube Headphone Amplifier With Tone Controls

Overview

The Fosi Audio GR70 Tube Headphone Amplifier blends classic tube warmth with modern engineering in a compact, elegant form. Designed for headphone enthusiasts and home-audio listeners alike, it captures the character of vintage amplification while providing clean, controlled power for today’s high-resolution sources.

At the heart of the GR70 from Fosi Audio are four vacuum tubes — two 5654W for voltage gain and two 6AC7 tubes for power amplification — forming a two-stage pure-tube topology. This design delivers a smooth, balanced presentation with rich midrange texture, silky treble, and an inviting sense of space. Every note flows naturally, revealing the subtle detail and musicality that make tube listening so distinctive.

Despite its compact footprint, the Fosi GR70 tube headphone amp is a capable performer. It outputs up to 300 mW @ 32 Ω with signal-to-noise ratio ≥ 97 dB, supporting headphones from 16 Ω to 300 Ω across low- and high-impedance modes. Whether driving sensitive IEMs or demanding over-ears, it maintains low distortion and consistent tonal balance.

Built from CNC-machined aluminium, the chassis feels reassuringly solid yet refined. Dual-side ventilation keeps the tubes running cool, while tactile controls — volume, bass, treble, and impedance selection — make the amplifier intuitive to operate. Both 6.35 mm and 3.5 mm headphone outputs, plus RCA input/output, allow integration into desktop or home-hi-fi systems.

For Groove Central headphones listeners, the Fosi GR70 tube amplifier offers a perfect meeting of nostalgia and precision. Its glow invites you in; its sound keeps you listening — open, warm, and effortlessly musical.

Key Features

• Four-tube design using two 5654W and two 6AC7 tubes for pure dual-stage amplification

• Supports both low (16 Ω – 120 Ω) and high (120 Ω – 300 Ω) impedance headphones

• Delivers up to 300 mW output @ 32 Ω with SNR ≥ 97 dB and THD ≤ 0.5 %

• Bass and treble controls allow fine-tuning of tonal balance to suit your music

• RCA input and output for integration with home hi-fi or powered speakers

• Front panel offers both 6.35 mm and 3.5 mm headphone outputs

• Durable CNC-machined aluminium enclosure with dual ventilation for thermal stability

• Compact 12 V design suitable for desktop or living-room audio systems

• Hand-finished controls for a refined user experience and classic tube aesthetic

Technical Stuff 

A Visual Intro - Fosi Audio GR70 Tube Headphone Amplifier ...

For More Information

Visit the manufacturer's website.

Returns Policy

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Should you wish to return your order, please notify us within 14 days of purchase with a valid reason for return. If we are unable to resolve your complaint or further assist you, we will process a refund upon timely receipt of the goods purchased. Unopened goods will be refunded in full. Refunds will be processed promptly and payment made by the same method that you made payment. All refunds are made at the discretion of groovecentral.com.au.

Shipping

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