I felt I must go overboard on the ratings to rectify the ratings from other reviewers who misunderstand what this product is meant for. It is designed to split one signal into two, not combine two into one. I don't completely remember the science behind it but there is a valid reason. So, for those who want to listen to two or more things at once, you will need a mixer.

The thing with this little splitter is, from a stereo it can split that into 2 stereo signals say an output headphone jack to 2 headphones, not the other way around. It won't allow you to combine 2 signals and route them into one jack. That would be a miracle or a noisey mess.

I play bass, and use earbuds to listen to a song, while using studio headset over the earbuds plugged into the amp.. The earbuds were driving me crazy so I bought this to plug my bass and MP3 Player into the amp and have only the studio headset.

My bass went threw clearly, until I turned on the MP3 Player, then it went threw, but not my bass. Basically saying, it has two jacks, but will only take one at a time.

I bought this thing for my bass because earbuds damage your ability to hear bass but where the only thing that would fit in my studio headset. (I play my bass on my amp with the studio headset, and MP3 player with earbuds.)

When I first plugged the guitar in, it came out clearly and well, but when I plugged the MP3 player it compleately dropped the guitar. I then unplugged my MP3 player and plugged in my keyboard instead (so I had a guitar and keyboard plugged in). They both came threw but with TERRIBLE quality. I then plugged my MP3 player back in and it worked that time, but I could barely hear the guitar.

I'm not going to bother taking it back because it's cheep, but I was really disappointed with it, and I've only had it for a few hours.