Toxic amplifier generating noises

[Mote]

This is Toxic TX960 amplifier.
When I received the amp, it seemed that it would be a easy fix, two blown output transistors, two emitter resistors read open. I replaced them.
I worked on it a week ago and I did not make any notes, because I thought it would be just a case of replacing transistors. So now I do not remember original symptoms, I think I had about 4V, 18V, 4V on outputs of one channel.
I measured about 1V on output of one of the opamps (number 1 on picture).
I removed the opamp and got clean audio on other three channels.
Original opamp was IL4558S-9, ofcourse local stores did not have in stock. So I replaced it with NJM4558L. It has one pin less, but the original opamp had two pins for V+ other pins are in inverted order so I could use them.
Now I get various loud noises from speaker outputs of all 4 channels. Noises change pitch/tone when I turn LPF, HPF knobs switches. Output on scope is on attached picture 2. Waveforms on various outputs of opamps are on other pictures.
Pictured 4 opamps are only for channels one and two. When I disconnect board with opamps for channels 3 and 4 I get no noises from outputs of channels 3 and 4. When board is connected and I remove opamps 3 and 4 from main PCB, then I get clean audio from channels 3 and 4.
Tomorrow I take opamps from board for channels 3 and 4 and insert them to main board, disconnect the other board and see if I can get clean audio on channels 1 and 2. So I can rule out fault in audio amplifier section of amp.

Any other suggestions what to do?

[Perry Babin]

If the noise only started when you added the non-inline op-amp, remove it to see if the problem goes away.

[Mote]

When I first installed the new opamp, I made a mistake and connected -V and +V together, I had RCA cable connected to that channel at the time, that must have damaged RCA shield -> Ground trace. It was broken in two places. I fix the trace and now amp plays clean audio on all 4 channels.