I also have a transformer "hummmmmm" coming from my Coronet. I contacted Jim Hagerman and he suggested that it might be due to my use of the original 270BX transformer. It is only rated for 210-215 volts. The 370BX transformer that is now used in his designs is rated to work on standard 220+ voltage.
He suggested either upgrading to the 370BX, with a few minor resistor changes, or putting a resistor in line with the mains to reduce the incoming voltage to about 210-215 (my home measures about 223 now).
Don't know if this is my true problem because I haven't had tme to try it. The hummmmm is very low and not noticeable when music is playing.
I do agree that the music coming out of this phono stage is very good. Excellent value for the money, and well worthwhile, especially with some cap upgrades (I used Sonicaps in mine).
Good luck,
Bob
He suggested either upgrading to the 370BX, with a few minor resistor changes, or putting a resistor in line with the mains to reduce the incoming voltage to about 210-215 (my home measures about 223 now).
Don't know if this is my true problem because I haven't had tme to try it. The hummmmm is very low and not noticeable when music is playing.
I do agree that the music coming out of this phono stage is very good. Excellent value for the money, and well worthwhile, especially with some cap upgrades (I used Sonicaps in mine).
Good luck,
Bob