audiobomber

Yes, I agree.

Check that the pins in the DAC USB port are correctly aligned. I managed to bend two pins while plugging a cable in. I straightened them by bending back into place with a tiny screwdriver, all good now. A computer repair tech told me this is a common problem with USB ports.

Crosby Stills & Nash were boring without Neil Young's rock edge.

My advice is to get this one; impeccable specs, pro build quality, audiophile approved sound quality, reasonable price: https://www.theabsolutesound.com/articles/oyaide-neo-d-class-a-usb-20-cable/

Check back with me in three years. I'm conducting a double blind test.

I've listened extensively for differences in USB cables from Oyaide, Ghent Audio, Vangard, Korg and several generics, including dual-head and USB 3.0. I hear significant differences among all of these in my main system and in my dedicated headphone system. I agree with whoever said that cost is not a determinant of SQ. Powering the DAC separately from the digital transport with a USB cable or iDefender is sometimes a major improvement, sometimes unnecessary. In my headphone system, I replaced a Ghent Audio dual-head USB cable with a USB A to B adapter (no cable, just a simple adapter), in my dedicated desktop system. The adapter is USB 3.0 because that is what iFi recommends with their iPurifier. I heard an immediate improvement in PRaT due to faster transient release and decay. I am very pleased with the Oyaide neo+ Class A in my main audio system, where it outperformed a more expensive Oyaide neo+ Class S cable and other USB cables mentioned above. If I could accommodate it physically, I would replace the Oyaide with a Sonore USB adapter. What is especially appealing with the Sonore is the 5V bus blocking switch. I use electrical tape to block the 5V pin on the Oyaide, which provides a significant improvement in the sound. My DAC does not use USB power and does not manage it well. YMMV, but do try blocking the USB 5V if your DAC is self-powered.

There's also a "Disagree" button, which is what I use when you post regarding cables. I agree, no effect, but it is therapeutic for me.

There's already an Off-Topic button. I pushed it on your post just to call your attention to this feature. 😁

Beyerdynamic applies the "Hi-Res Audio" logo to the Amiron Home, not to the DT 1990 Pro, despite broadly similar high frequency performance. IMO, "Hi-Res" is specified for the Amiron because it may matter to domestic consumers. Pro sound people are a lot less likely to care about this useless spec.

Who does this certification? I've never heard of it. The DT 1990 Pro was designed for music and sound professionals. Its bass and midrange frequency response with the Analytical pads is more accurate than the Amiron Home. High frequency response is broadly similar, so how could the Amiron be HI RES certified and not the 1990? Certifying the HD 660S and not the HD 650 is equally nonsensical. I had both the Amiron and 1990 at the same time, and sent the Amiron back because I value accurate sound over "fun" sound. Most people use the warmer Balanced pads with their DT 1990, I only use Analytical pads. The HD 650, another warm-sounding headphone, has been revered by audiophiles for decades, but again, I don't care for that sound. To me, the Amiron is like an HD 650 with more detail and better dynamics. I would say that most of the people at Head-Fi prefer the warmer sounding Amiron to the DT 1990. The Amiron can be easily configured for balanced operation with your DAP with a new cord. The DT 1990 has rather heavy clamping force, the Amiron clamping is best described as gentle. I believe the Amiron would be the safer choice for you, and for most people. The DT 1990 is the one for me. You might want to review this thread to help with your choice: https://www.head-fi.org/threads/professional-vs-home-beyerdynamic-dt-1990-pro-vs-beyerdynamic-amiron-home.838972/

It was already over.

That is the only part of your post I can agree with. I have a mechanical engineering background, people who design audio equipment have deep engineering and/or scientific backgrounds. Some of them post here. So your opinion that all engineers agree with your "measurements only" POV is clearly egotistical nonsense. My audio beliefs are based on extensive listening in my own system. Until I confirm it for myself, in my room, through my system, with my music, for an extended period, everything is just another opinion. I like to view measurements of audio gear, but measurements alone have not stood up to my personal reality test as a predictor of sound quality. I won't reply further, as this discussion is not about the Primo.

For anyone interested in the Primo, I recommend this video:

I assume you are saying this based on "scientific" theory and not actual listening experience? 🙄 I use Chromecast Audio, Raspberry Pi 3 B+ and SOtM sMs-200 streamers. I can assure you that none are broken, and none sound alike. The streamers even sound different from themselves when I change power supplies. This should not surprise anyone who actually listens and doesn't have a closed mind.

Porto, have you considered form factor? A larger, heavier open-back headphone like the DT 1990 is an unusual choice with a DAP. The supplied cords are also far from ideal for portability. Are you intending this combination for home use only?