This could be a longshot, but I had it happen to me. If you are using a video receiver or a multi-disk player that does its own decoding, it could be an obscure problem like this.
I recently reset the settings on my Oppo 105 universal disk player. In so doing, I chose the stereo settings since I am only using a stereo rig, but among the other settings I used neo 6 downmix settings. The first disk I put on was a james taylor recording that was recorded in multi-channel SACD. Just as you described there was a second slightly delayed and very electric sound on top of the stereo sound. I tried another strictly CD recording .... nothing, just normal. So I went back into the Oppo and illiminated the neo 6 downmix. That did the trick. As I said, a pretty esoteric thing but if nothing else seems to work .......
I recently reset the settings on my Oppo 105 universal disk player. In so doing, I chose the stereo settings since I am only using a stereo rig, but among the other settings I used neo 6 downmix settings. The first disk I put on was a james taylor recording that was recorded in multi-channel SACD. Just as you described there was a second slightly delayed and very electric sound on top of the stereo sound. I tried another strictly CD recording .... nothing, just normal. So I went back into the Oppo and illiminated the neo 6 downmix. That did the trick. As I said, a pretty esoteric thing but if nothing else seems to work .......