Hello, This is a follow up on a privious post concerning the buzz I'm getting through the speakers out of mt rebuilt Fisher. I did conclude that the buzz was coming from the 7199 driver tubes. I bought some adaptors and replaced the 7199's with 6gh8 . These 6gh8 tubes came out of a working tuner. I still have the buzzing. But I have discovered that I inadvertently left out the heater reference circuit for the amp section . Just dont know the best way to fix it sense I have installed the IBAM and individul carhode resistors. I have so far no discussion here on it so any suggestions or resources is appreciated.