I'm working a design for an all op-amp MM phono stage and I'm going to use a Salas shunt regulator for the +/0/- power supply. Using op-amps outside of guitar effects pedals and shunt power supplies with a negative rail are new to me so I have a couple of questions. Forgive my ignorance if the answers seem obvious.
Where will the turntable and the preamp chassis ground? The 0V audio ground or the V negative rail?
According to my math my circuit will require less than 200mA. Is this enough load to keep the shunt regulator operating properly?
Thanks for your help.
Where will the turntable and the preamp chassis ground? The 0V audio ground or the V negative rail?
According to my math my circuit will require less than 200mA. Is this enough load to keep the shunt regulator operating properly?
Thanks for your help.
The 0V terminal of the dual +/- DC supply is the ground reference for both the supplies and the input and output signals. Do not use the + or the - rail for ground.
My experience with turntable grounding is that the separate ground wire should go to the phono preamplifier chassis ground, and it should be connected to the PE (protective earth) of your electricity. BUT: the chassis ground should be separated from the L and R channel signal ground, that is the RCA connectors should be mounted isolated from the chassis. In your case the signal ground is the 0V of the power supply.
Search also "ground loop breaker", it applies for Class I appliances, that is when the matal chassis and case is connected to the protective earth. For Class II phono preamplifier (isolated plastic or wooden case) and 2-prong mains cable this is not an issue.
Search also "ground loop breaker", it applies for Class I appliances, that is when the matal chassis and case is connected to the protective earth. For Class II phono preamplifier (isolated plastic or wooden case) and 2-prong mains cable this is not an issue.