I'm putting a small first system together for my youngest son. I've already selected a tube amp and speakers from what I have on hand. I wanted to put together a simple preamp to go with them.
I bought a Zerozone M7 line stage board kit and the recommended R-Core transformer.
I haven't used R-Core's before. The board has connections for the two orange 14v heater winding wires, and the two blue B+ wires. There is a wire marked "N:yellow/green". A dumb question, but
Is this a center tap? I can't get any readings using an ohm meter. Not reading to the frame either.
There isn't any connection for a center tap on the board.
Below is a picture of the transformer and the end of the board where the wires connect. I'm used to heavy iron core and toroidal that come with diagrams of the windings.
Thanks.
I bought a Zerozone M7 line stage board kit and the recommended R-Core transformer.
I haven't used R-Core's before. The board has connections for the two orange 14v heater winding wires, and the two blue B+ wires. There is a wire marked "N:yellow/green". A dumb question, but
Is this a center tap? I can't get any readings using an ohm meter. Not reading to the frame either.
There isn't any connection for a center tap on the board.
Below is a picture of the transformer and the end of the board where the wires connect. I'm used to heavy iron core and toroidal that come with diagrams of the windings.
Thanks.
Attachments
I’m looking at an R core I used for a dac I built and I believe that yellow/green is a ground wire. The N is neutral but also is tied to the ground buss. Don’t wish to mislead you so let’s see what others think
Yellow/Green is for AC line ground (presumably its for some sort of shielding in the transformer). Neutral is only connected to ground (in the US anyway) in two places: Where the power comes into the building, and at the power distribution transformer on the telephone/power pole. In both of those places there is also a ground rod connected to neutral and ground.
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Thanks guys. Earth ground it is.
I found a couple pictures of preamps that were sold under a couple brand names using this board and transformer. All I could see was a small bit of that wire right where it comes from the transformer. I couldn't see where it was connected anywhere. I thought maybe it was grounded at one of the mounting screws of the transformer closest to the wire.
Thanks again, this clears things up.
I found a couple pictures of preamps that were sold under a couple brand names using this board and transformer. All I could see was a small bit of that wire right where it comes from the transformer. I couldn't see where it was connected anywhere. I thought maybe it was grounded at one of the mounting screws of the transformer closest to the wire.
Thanks again, this clears things up.
The yellow-green wire is going to the electrostatic screen. It shall be connected to chassis ground. Example in the preamp I built.
Sometimes the transformer has a label with wires destination (here in a phono preamp I built years ago) ...
Sometimes the transformer has a label with wires destination (here in a phono preamp I built years ago) ...
Thank you. I'll connect it to the chassis and the earth ground on the IEC socket.
Other than the grounds for the signal input and output, there isn't Any ground connection on this board for a chassis or earth ground. Kind of odd, it's the first board I've used like that.
Other than the grounds for the signal input and output, there isn't Any ground connection on this board for a chassis or earth ground. Kind of odd, it's the first board I've used like that.