I have used the Binary 260 Series 4K Audio Extractor and have had no issues. This unit does not convert from surround to 2 channel but it does have an EDID switch so you can force the device to send the desired audio format. If you want one that will maintain surround and also downmix a stereo output I think the Atlona AT-HDR-M2C will do that. The Atlona is obviously much more expensive.