Ampeg SVT 4 Pro bias confusion

[Axtman]

I picked up a nonfunctioning Ampeg SVT 4 Pro amp bass head. The amp had soo many blown components on the main board that I installed a new main board.

The schematic I have (1999) says to bias the FETs at 25mv accross the source resistors. There is a guy on YouTube who is biasing the same amp. He shows instructions on the screen that says bias the FETs to 10mv. Which one is correct?

 

[agedhorse]

Good question, maybe a call to Ampeg might be helpful but generally I believe the manufacturer's information long before I believe some YouTube video... in fact YouTube videos are more often incorrect than correct IME.