FET10e Channel Noise

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Hello all! New user looking for assistance troubleshooting a fet10e. Recently right channel began "making noise". Narrowed down with O-scope to sinusiodal inputs resulting in 1/2 wave rectified output. Further checking, it appears the output transistors Q8, Q9 are not biased on (comp1 voltage is ~0.4v, while on good channel it is around 0.88v). I suspect component hfe drift, possbily requiring adjustment of pot or component replacement.

Anyone have any suggestions? Thx.
 
Official Court Jester
Joined 2003
Paid Member
Q8 and Q9 ?

on which schematic ?

this one ?
 

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