Fosi Audio GR70 is a new tube headphone amplifier with the ability to work as a preamplifier. This compact and stylish device combines classic analog sound with modern features, allowing you to get rich, warm and detailed sound with both over-ear and in-ear headphones. The GR70 supports two gain modes and allows you to connect headphones with an impedance of 16 to 300 ohms.
The design uses a cascade of four tubes: two miniature 5654W act as a driver, and two 6Ж4 tubes (analog 6AC7) work as an output cascade. This configuration provides a transparent and balanced feed, while users can experiment with replacing the tubes, selecting the sound to their preferences.
The device is equipped with bass and treble controls, an impedance switch and a large volume knob. The front panel provides 3.5 and 6.35 mm headphone outputs, and the back has an RCA input and RCA output, which simplifies integration into a home audio system. The body is made of solid aluminum, which makes the amplifier durable and resistant to vibrations. Despite its compact size, it produces up to 830 mW at 32 ohms at high gain.
Fosi Audio GR70 specifications:
- Lamp type: 6Ж4 ×2 / 5654 ×2
- Input: RCA
- Output: 3.5mm / 6.35mm / RCA
- Tone control: yes
- Output Power: 67mW (Low Gain) / 830mW (High Gain) into 32 Ohms
- Headphone support: 16-300 ohms
- Frequency range: 20 Hz – 20 kHz (±1 dB)
- Signal to noise ratio: 97 dB
- Dynamic range: 97 dB
- Distortion level: RCA ≤0.26% / headphones ≤0.5%
- Power supply: 12V, 3A
