• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Grounding

Can anyone tell me the correct way to ground a circuit when using two or more power transformers. I am supplying the power tubes (300B) with one transformer and the and the input tube (6sn7) with another transformer. The first circuit uses tube rectification and the second uses SS. I usually ground the circuits together. Also always use house ground.
 
Last edited:

6A3sUMMER

Member
2016-06-07 6:50 am
First make the ground loops, local loops.
Example:

B+ #1, CLC or CRC filter #1
Connect B+ center tap to the first filter cap negative, then connect from the first filter cap negative to the second cap negative. Keep these wires short (parts close together).

B+ #2, CLC or CRC filter #2
Connect B+ #2 center tap to the first filter cap negative, then connect from the first filter cap negative to the second cap negative. Keep these wires short (parts close together).

Now, connect the negative of the 2nd filter cap of B+ #1 to the negative of the 2nd filter cap of B+ #2. Then connect from there to the amplifier's central common ground.

The idea is to keep the impulse transients of the two B+ circuits local, and not onto the amplifier's common ground. (The local loop is Rectifier, Cap +, Cap -, Center tap; then first cap -, second cap -).