Color Preamp Heater Grounding
Hi all, I am building the color preamp and having a lot of fun doing it. THis is my first tube build and first point-to-point build so I'm learning a ton. One thing that has me stumped is how to ground the 6.3v heater circuit. I'm using the Hammond 269jx without the center tap. The schematic shows the resistors after the 12au7 tubes - but I'm assuming they are supposed to go in the power supply half of the amp? Right now I have the 2 green wires from the transforer that carry the 6.3v connected to the solder lug as shown in the video and then I used yellow & purple to connect that to the rectifier tube and 12au7 tubes. That same lug I connected one of the 2 resistors to each and the other end of each resistor to the ground lug. Is that correct? I don't have a picture of the resistors but you can see in the picture below to the right of the capacitor where I am talking about. If that's not correct where should I physically be putting those capacitors? Thanks!


Yes, you are creating a virtual center tap with the two 100ohm 2W resistors. On that tag strip, one end of each resistor goes to each of the heater wires, the other end to the star ground point.