Pure Direct sounding worse than straight stereo in HTPC setup?
I've been searching for answers on in the internet (including from these forums) of why my Pure Direct on Yamaha RX-A2030 sounds a bit worse (not much though) than straight stereo. Straight stereo has higher highs and wider bass on the lower end on my setup. I wonder why though, because I'm not using any EQ or enhancements on the receiver (set to "through") and am keeping the setting on straight 2-channel stereo. Only things that have been "set" are the distances of the speakers to the listener on the couch. Shouldn't the Pure Direct almost always sound best as it doesn't color the signal?
My setup is following: from my PC's GPU a HDMI cable goes all the way to the AVR on the other room, and from AVR the cables go to my two Amphion Argon 3L tower speakers on each side of my Sony TV. I'm using Sony TV as a secondary monitor to my PC from which I play almost all my music from Spotify Premium app from PC. To my knowledge, the pure direct setting bypasses all the DSP in the receiver using only the receiver's DAC? So is it the DAC to blame on on the RX-A2030? I had Yamaha RX-v767 before RX-A2030 and although the sound is much better now with a more powerful receiver, the pure direct mode on RX-v767 had the same problem, sounding worse on Pure Direct than "straight stereo". At least, I don't think the speakers are to blame because they're quite high-end 8ohm speakers with frequency response of 30 - 30k Hz, costing nearly 3000 € a new pair.
So if I'm using the Pure Direct on my setup, is the setting using the DAC on my GPU, or the one in the receiver? And in this case altogether, why does the "straight, 2-channel/stereo" settings are giving me fuller sound than pure direct, even though I'm not even using EQ or any other processed music mode?