I checked - I had purchased this from Amazon - it did not work for me. I don't know if it was defective or it is not meant to convert stereo signal into mono in the first place and I used it incorrectly - hard to tell from descriptions. The 1-BUD Stereo-to-Mono Converter does work tho - so I don't know if the Amazon product was a defective Chinese product or my incorrect use of it.