Hello, I have two M267 Series mixers, they look identical. Both units have the switchable peak limiter with the red LED. Unit one has a LIMITER THRESHOLD ADJUST CONTROL accessable through the bottom of the chassis to set the desired level. Unit two does not have this adjustment on the bottom of the chassis. I would like to set the peak limiter to the same level on both units. How do I adjust the peak limiter on unit two and where is it located?
How do I adjust the peak limiter on unit two and where is it located?
* The older unit that you have does not have an adjustment. The limiter threshold was preset by component values on the circuit board. The unit with an adjustable limiter had a redesigned limiter circuit.
For the older unit:
R254 should be a 22kohm resistor. Find it near C227.
Add a 22kohm resistor in parallel to R254 drops the threshold by 6dB.
Add a 56kohm resistor in parallel to R254 drops the threshold by 3dB.
Adding a variable resistor across R254 will give you a variable limiter threshold.
One more thing: the LED indicator will not track the new threshold.