I solved the level issue today. I did not realize that I had to place a 600 ohm load on the input. I discovered that after reading through a Panasonic VP-7721A audio Analyzer manual. This unit is very similar to the Meguro MAK-6581. And manual is much better than the Meguro manual. Luckily I have a Leader Dummy Load, and I confirmed the reading. Without the 600 ohm termination the unit would read 6dB higher than what the digital readout is showing.
If anyone need the Panasonic manual they can message me.
I also have a Meguro MAK 6581. When I turn on the unit all the lights comes on and stay on. The troubleshooting section in the manual said the to "press the CPU reset switch". But I could not find that anywhere. It took me a long time to figure out that the switch is in the hole on the side of the unit. Terrible instructions.
I also notice that (for example) when I set the output level to 0.775v at 1kHz and measure it on the meter, the level doubles to 1.55v. Other levels such as 1.23v also doubles at the output to 2.46.
This is strange. Can you check your Meguro to see if it does this also? Pleasse let me know.