The Quality of sound of sound was much better with my 6035 analog mode. I tried to force the 7135 to stay in analog mode but it goes right back to digital mode after the call. I tried so many ways but couldn't force it to saty in ANALOG only. Is there anyone who has been succesful? I called verizon and they said ..Yes it is a tri-mode and it should but they couldn't figure it. They send me another phone, but it wasn't the phone. Any suggestions?