Musical Fidelity X-A50 monoblock amp help

[Ianmac]

Trying to bring a pair of these back to life.
Does anyone know the correct procedure for setting the quiescent current for the output transistors and what this current should be ?

[Firebottle]

I have found a picture of a clone board, this has only one adjustable resistor on it.
Assuming the real thing is similar then this will be the adjustment for the quiescent current. For a 50W amp I would suggest setting the current between 50 to 100mA.

If you get any distortion at very low levels with 50mA then set it higher.
You need to measure the current consumption of the pcb, preferably just the current in the output transistors. If you can only measure the total current of the pcb then add another 10mA to the above figures.

[Ianmac]

I have managed to get a cct of the original MF design and the equivalent for the output transistors.
There is one pot on the board which will set the bias on the output transistors. I want to change to a multi turn pot
Ill go for 50mA as you suggest and work upwards if needed.
Many thanks for your help.