I'm happy to get a manual from this rare old amp. The pdf is from good qualty.
Text excerpt from page 278 (click to view)
8-5. White balance Adjustment
1. Connect the oscilloscope to �MON_CB� and �MON_G� on the VFK1308P. 2. Open the �LCD adjustment menu�. 3. Select �5. White balance adjustment� in the LCD adjustment menu, and then press the �Enter� key.
4. Adjust level difference between �a� (MON_CB) and �b� (MON_G) to become +50mV±50mV as shown in figure. Note: 1) Signal level can be adjusted by press arrow keys on keyboard. 2) Waveform (figure) can be displayed by press F2 key. 5. When adjustment is finished, press ENTER key to adjusted data write to EEPROM, then change the display indicated as below.
6. Connect the oscilloscope to �MON_B� and �MON_G� on the VFK1308P. 7. Adjust level difference between �a� (MON_B) and �b� (MON_G) to become +300mV±50mV as shown in figure. Note: 1) Signal level can be adjusted by press arrow keys on keyboard. 2) Waveform (figure) can be displayed by press F2 key. 8. When adjustment is finished, press ENTER key to adjusted data write to EEPROM.