I bought a Kenwood KA-7150 the other day and had trouble with the left channel, there was either no volume or very low volume. I took it to my service tech and they cleaned all the pots and switches. When I got it home it was still doing the same thing except the problem sometimes occurs on the right channel also. I took it back to the tech. Today I received a call telling me the speaker switch is failing. They say they cannot find a replacement (not a surprise to me on an amp this old.) Has anyone else had this problem? Is there any replacement available? Thanks for any replies or help.