Mark Levinson JC-2

Good afternoon, I bought some boards like these but they didn't send the voltage values I have to have at each point. I needed help figuring out these values. Thanks

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Bear in mind that these boards are unauthorized copies, and may differ in a number of respects from the real boards.
There is no way to know what the voltages should be, or what the actual schematic of the board is.
They also illegally use the Mark Levinson logo.
 
I wanted to know if someone had bought a similar board because several preamps already assembled with the same board are sold, I wanted to know what values I have to have at points A, B, C and D because the power supply speaker can already know it has to be 15v.
 
The 15 volt regulators are not the original JC power supply, but are OK, but better to use Jung super regulator, but that takes more space and money.
the line amp is not the same as the original, the jfets and transistors are different and the schematic is not the original so who knows what the design Is. You need to show the bottom of the pc board. Match the jfets for idss within 10% or better
 
I wanted to know if someone had bought a similar board because several preamps already assembled with the same board are sold, I wanted to know what values I have to have at points A, B, C and D because the power supply speaker can already know it has to be 15v.
You have not marked A,B,C and D:
Speaker 15v?
You mean supply regulator's
Alvalues are marked on the PCB