Ampeg SVT 4 Pro- A channel weak

[Bigdrums]

Some time back I took in this amp for repair finding a TLO74 (IC101) had burnt. I socketed and replaced both A & B channel. The A channel remained with a weak output. I checked everything I could.
It occured to me that it might be something in the vicinity of the burnt TLO74 so I started looking at a J176 (Q101) and the optocoupler (OC101) right near it. When I measured the J-FET I got high but even readings with the ohm meter about G-S 1.025, G-D 1.041. But checking the B channel more like 0.025. Neither seems right but the B channel works so I'm assuming I need to change the A channel J-Fet.
Checking the optocoupler I measure 1.775 diode mode and nothing on the sensor side. These are not consistent with the working channel. So I need to replace the coupler also.

My question is if these two devices are bad, will it affect the speaker outputs? Ampeg_svt_4pro_sch.pdf Pg 4

[x-pro]

The optocoupler with the control circuitry is a limiter. If this node is defective, the limiter will not work. How can it affect the speakers? If the signal is too large, there may be distortion. There will also be no display of the limiter indication if the control circuitry is defective. If the chip was defective, check diodes D101, D192 in the meantime