If you want an entry-level DAC for your computer, the iFi Zen DAC is the way to go. The sound produced by this little device is truly crystal clear and sweet to the point where I would say it is as good as a preamplifier with five times the price. When you purchase it, don't forget to upgrade the firmware, which you can download from the iFi website. Also, if you want to get 100% out of the DAC, I would recommend the iPower power supply from iFi for an additional 60 euros. As a headphone amplifier, it is not very powerful, but if combined with the iFi Zen CAN, it can work perfectly with headphones like Sennheiser HD 650, 600, 560s, 660s, etc. I highly recommend it, but be aware that when you hear the sound and realize how big the difference is, you will be so amazed that you will end up buying the whole package.

Wonderful warm sound, buying a 5V power supply takes it even further, and the 5.3c firmware improves it by upscaling the mp3s.

I have to say that the Phoenix 41 is excellent, it knows a lot about sound and to tell the truth, I read the review about the Koss KPH30i and I thought I wouldn't try them for 40 euros to see what they're like... and it was absolutely right.

The only thing I have to add, since I have the IFI nano, is that in Single Ended, meaning Unbalanced, the Nano was much more powerful. In all the headphones I tried, HD 600, 650, 660, 1990, Sundara, 770 250ohm, it was equally weak. This is because the HD 660s that I have in the box had a Balanced 4.4 pentagon that I don't need because I have FOW clair hybrid 3.5 for Sennheiser. I thought I wouldn't try the 4.4 to see if it makes a difference. And yes, with the 4.4, the Zen is much more powerful. I dare to say that it's slightly above the Nano's maximum volume. In terms of sound quality, to tell the truth, I don't notice any difference at least in my ears. Also, the Nano even in SE sounded warmer, cleaner, I don't know, maybe because it has the built-in IFI purifier and it provides a better signal than USB? Maybe...

If someone intends to have only 4.4 balanced, they should go for the Zen. However, if someone is like me, who has many headphones and they are all 3.5 or with a 6.3 adapter, then due to power and convenience, they should blindly go for the IFI nano.

The problem with the 4.4 is that it's difficult to find cables for headphones like the Sundara, HD6 series, and besides that, there are also headphones that don't support Balanced, like the Beyers, so there will be a problem there.

The IFI nano can also work with 3.5 Balanced, but it's extremely difficult to find a good quality cable under 150 euros for 3.5. Also, the 3.5 IFI has a completely different internal connection, and when you buy it, it will only work with the specific IFI 3.5, which in essence has been abandoned by IFI itself for the 4.4 Pentacon.

For its price, it's amazing, and I would keep it in place of the nano if it had the same power as SE, so it could work with all headphones.

PS. I tried it with USB and not 5v.

For those who are too lazy to read... If your headphones are up to 150 ohms and have a sensitivity of over 100, then it will be great (unbalanced). Otherwise, go for the IFI micro or Fiio k5pro.

It's perfect for an entry-level audio upgrade (always talking about pc). Amplifier/DAC combo, you avoid all the hassle with one purchase. USB from the pc and you're ready.

In terms of "power", you can't really call it the most powerful machine that has ever existed, quite the opposite actually. Compared to the Schiit Magni 3, it gives significantly fewer mW to headphones with the same Ohms, so it "forces" you to press the power match (the name ifi uses for the high/low gain switch) more often to give the output of the high gain. However, for its price, which is almost ridiculous, it gives you a 4.4 pentaconn balanced output, so if you have good headphones/iems, it would be good to invest in 4.4mm cables as it will significantly improve the sound, both with the additional power provided by the balanced connection and with the greater separation and noise reduction. (Update: the 4.4 cables I ordered finally arrived. O.M.G.! The difference is huge)

(It doesn't come with an external power transformer, for starters it connects and draws power only from the USB. The power supply from the computer's USB is unreliable at best and causes a lot of interference. It is recommended to purchase a power supply as it will improve the sound due to better and higher quality power supply)

The sound is, in one word, smooth, and in a second word, effortless. It may lose some details in the highs compared to the Magni (sorry for mentioning it constantly, but I currently have it as a comparison benchmark), but it definitely makes you want to keep listening for a much longer time. It doesn't lack at all in the midrange/lows, only the highs have been pulled back for the sake of "smoothness".

Lastly, the elephant in the room, the bass boost. It works, it doesn't overshadow the mids like other bass boosts do, it does what it promises and nothing else, and it does it well. The only limitation is the headphones you use. If they are bass light, then turn it on and leave it open forever, you won't regret it. But if you have headphones that are either bass cannons or simply more balanced in frequency response, then it's better to leave it closed as it shakes your head and becomes tiring after a while. It might make some songs that don't have bass on their own a bit more interesting, but you have to be constantly click-on click-off.

Fantastic Construction / Fantastic Sound!
This little thing works wonders.... There is an upgrade compared to the smartphone when playing directly from the amplifier, the sound became even more detailed than it was before, it remained balanced without being tiring, the low range went down a little bit. Metal Jazz shines. All songs play with the same quality. Wiring "dynavox 207619 perfect sound".