The Talking Machine Forum — For All Antique Phonographs & Recordings

Hello all~

I'm hoping you may be able to help diagnose a problem with my Brunswick Panatrope 148c (1926). I had to replace the original volume control because the original had failed. The original was an exposed wire resistor with a wiper that touched various points of the resistor. The resistor was open, not measuring varying stages of resistance.

When I replaced it with a more contemporary potentiometer I experience annoying hum in the middle of the volume control. If it's at max, there's no hum, but it's way too loud to be enjoyable. If it's all the way down, you obviously can't hear the music, but the hum is gone. One friend suggested putting a .1mfd capacitor between the center terminal (wiper) and one of the other terminals. Another friend suggested I create a dead short between the center terminal (wiper) and one of the others. I don't want to damage the unit with putting a capacitor in the wrong place and I would also not want a capacitor that was incorrectly wired to blow up on me.

Damon
St. Louis, MO

You should be able to stop the hum by adding a ground wire to the case of the volume control.The Victor 9-55 uses the same volume control and amp mine also had open segments I was able to melt out the tar like substance and add resistors to the open segments.