What is the perfect sound card for the Tiamat 7.1 v2?

Hello, I'm new to the community. But I think I come up with a topic that can help many of us ... First of all I just got a Tiamat 7.1 v2 and I have a motherboard that supports this Razer headset. But the discussion itself is not what I have, but the INTERNAL sound card that has 7.1 support that is perfect to get the best point out of these headphones. And although I searched quite a bit, I came to the conclusion that the Asus Strix Raid DLX could be perfect and not extremely expensive, The problem started when I realized that after placing the Asus sound card, you have to connect the volume controller that occupies 3 analog outputs, leaving only 4. Automatically I realized that it was not going to work with my headphones or I would have to leave aside the Asus volume controller. So I came to the conclusion that there is something that I am lacking in knowledge of the subject and I am looking for a person who can advise me wisely. From already thank you very much.