Fosi Audio Gr70 headphone amplifier and preamplifier first impressions and quick test, personal opinion.
It is important to note that the manufacturer does not provide financial support and I can always describe my full and honest experiences.
I recently received a new headphone amplifier and preamplifier from Fosi Audio. This little jewel box is called the GR70. Let's see what we get first, the contents of the box:
1. The GR70
2. 2 pcs 5654W tubes
3. 2 pcs 6Ж4 tubes
4. Wall power supply.
5. User manual
After assembly, you may understand why I called it a jewelry box. I really like it! It can also be a decoration for the table.
I will introduce the device in two parts. Let’s see the first impressions and the use as a preamplifier.
So, the appearance is completely fantastic for me! I simply love it. It's pretty, elegant, modern. Yet it has a retro feel to it because of the tubes. The huge volume knob, which is also the power button, completely dominates the top
The tubes are 5654W and two 6Ж4. The 5654w is responsible for the current amplification, while the 6Ж4 is responsible for the sound. The tubes can be replaced as needed…
On the front, from left to right, you can find the gain level switch. The two types of jack outputs are 6.3 mm and 3.5mm, then the two equalizer buttons. Unfortunately, for some reason there is no general system in the arrangement of the buttons. For example, in the zp3 and normal hifi components, the order of the treble and bass is reverse. Generally, the bass is on the left and the treble adjustment button is to the right. Here it's reversed. It must have been just a funny, tangled elf who ran into the factory
The high volume button is very smooth. It can be easily switched delicately. A little too easy, I accidentally turned it off a few times. Once you get used to it, it's perfect. The preamplification level is impeccable. It supports the v3 mono at the right level and the volume can be adjusted very finely.
The back:
You can see the serious size connectors, good quality, mountable RCA sockets. The connections are stable. Much more solid than the sockets you are used to. Plus point for the designer!
from the side:
The two-sized headphone output is a good idea. The connectors on my older headphones are 6.35mm/ 3.5mm size (but many modern headphones use the 4,4mm.. it's not here)
As a preamplifier, I have to say that it's excellent! It's simply magical how it brings tube warmth to the sound without losing even a little bit of its clarity, even the smallest details remain. There is no distorted or blurry detail. I tested it in two ways, but both are preamplifier mode. In one, I put it after the zp3 preamplifier in front of the power amps just because of its sound, in the other mode I used it directly as a preamplifier between the dac and the power amps. The sound was simply enchanting. It may be the wrong word, but I hear the sound much more analog this way. Every little detail remains and we get the warm tube sound. It's fantastic what it can bring out of instrumental music. Of course, it's important that the quality of the music played is as good as possible. It was able to bring on the most in the sound of the instruments, they are much more lifelike than when listening without the gr70. But in fact, it's not only jazz or big orchestrals that can sound good, but anything. be it vocals with acoustic accompaniment or electronic music. Its sound is full of life and warm. It can be listened to for a long time. It gives the warm of the tube sound while preserving the smallest details. It adds even more spatial depth to the music. It's all very enjoyable. Since tubes can be used to go upgrade, its sound can also be taken to a higher level. It seems to handle the low sound a little richer. Technical content. You can find a more detailed description and price on the manufacturer's website.
Let's see how it works as a headphone amplifier: First, I tested the volume with some headphones that I use with my phone. Well, while as a preamp you get plenty of volume, with the small headphones I couldn't get it too loud. The higher output level proved to be sufficient, but the headphone volume was not very much. However, the Fosi Audio i5 headphones arrived. The situation was completely different. The signal level here proved to be ample. When switched to the higher level, the gr70 was already very loud at about half the volume. I'm not saying that they matched perfectly in sound, but they sounded very pleasant. The sound is extremely clean, warm and detailed. The volume control is just as impeccable as if I were using it only as a preamp. The jack sockets are tight, both make good contact. The resulting sound quality is very good. A little spare volume is still missing to be able to drive any headphones. The i5 also feels better if its support is higher. But the GR70 is still very enjoyable in every way. Bass control seems a bit lacking with headphones. preamp mode the bass perfect. Actually, the layout of the tone buttons and the slightly higher performance are the only things that could be mentioned. I really liked the rest.
I definitely recommend it. Very good value for money! Even as a preamplifier it really improved the sound.
Pros: The device is very nice, excellent stable construction, strong massive connectors.
Very good, pleasant warm tube sound while retaining fine details.
Sufficiently good preamplification level on the RCA output.
Two-level headphone amplification (switchable)
This is the most finely adjustable volume control so far.
Cons: It's easy to accidentally turn it off.
I would reverse the order of the tone buttons and try not to assign them to devices
randomly in the future.
The headphone outputs need a little more power.
Bass control seems a bit lacking with headphones. preamp mode the bass perfect
