Sound Oasis make good quality sound machines that are specifically made for people with tinnitus. Its primary purpose is to treat tinnitus and hyperacusis while you sleep, not necessarily to assist in getting you off to sleep. There could be more than one reason for it irritating your ears. Try using the streaming water app, which sounds softer than white noise and one of my favourites. You might also be setting the sound too loud. It should be at a volume where you are able to easily ignore it and should not be drawing attention to itself.Any suggestions? I have found that moving the speaker to a more central location and not 6 inches from my ear helps a bit but I have to turn the volume up.
The sound machine should be placed by your bedside and not too far away. Eighteen inches is about right. You might want to consider getting your hearing checked to see whether you have any hearing loss. All Oasis Sound machines are good but they do vary in sound quality. I have three models, the S-5000 is their best. S-650 is very popular and the model I regularly recommend. S-850 Travel, smallest of the Oasis Sound machines and is very high quality. Has in-built sound apps like the S-5000 so doesn't use sound cards like the S-650.
Michael