That is strange. Have you tried going to the on-board sound? I use that, via HDMI. It shows as video, and also as SonyAmp, so it takes some playing with the audio controls in the, in my case, Realtek controls and connect the SonyAmp. There is no equalizer control using this, but I don't want that in the audio stream anyway, since it can be adjusted better using the receiver's options. I'd like to upgrade to a good sound card, but for now, it sounds phenomenal! A pair of KEF C-40s, with dual 8" drivers and a Polk Audio PSW505 sub, and the upgrade in sound quality is amazing!
Picking up a pair of B&W 601Se speakers tomorrow! Surround for gaming and music.
EDIT: Of course, in your case, the selection will be different; mebbe something like "YamahaAmp" or similar.
i7-6700k @4ghz/gtx 980ti SC+/Sandisk256gb SSD-Toshiba 2TB HDD/Asrock z170 Extreme 4 mobo/16gb 2133 ram/Sound via Pioneer Elite vsx-90/B&W 601se/KEF C-40(dual-8"driver mini-towers)/SVS PB-2000 sub/FiiO E17 Alpen DAC/Audio Technica M50 headphones(never used! heheh)/Crossover 2560x1440 monitor