I did a search for this subject and did not find anything. Has anyone ever used or heard one of these used on a bass ? I looked at one at a local shop yesterday, but no one could give me any info on it and its not exactly something i could try out because the tube goes into your mouth. I am not even sure if I could return the thing if I was to buy it only to find out I did not like it...I know I would not want to try a used one...ICK!!!