Krell KSA-250 bias adjust

[willcycle]

Hi,

For those familiar with the KSA-250's internals (Anatech?) I would like to lower the bias a little on my unit. The output of an opamp used as part of a comparator circuit drives the input LED of an optical coupler (CNY-17) which controls the current into the base of a bias transistor. The comparator opamp drives the LED through a 511 ohm resistor designated as R156. Would increasing the value of this resistor reduce the bias? My thinking is reducing the current into the optical coupler will result in less current to the base of the driver transistor which should reduce bias.

Thanks,
Will