Amplifier circuit making clicking and screeching noises

[abdullahseba]

Hi
I made a complex multi amplifier circuit which had a very decent sound output when I first made it.
A few weeks later (in which it was not used) I was installing it and all I got was clicking sounds and random loud screeching almost like an old analog radio that not tuned in properly.
The speaker still produces sound and sometimes stops the screeching but the clicking is still there.
Its not the usual 50Hz hum afaik but more spaced out probably about 250ms (I dont have oscilloscope to measure it) and the TDA7266D (U3) also makes a similer noise since it was made but much lower that I wasn't bothered about it.
The main amplifier is the TPA3124D2 (U5 & U8).
Dont think this has anything to do with it but when no speaker is connected you can hear the audio coming from the PCB, probably through the inductors .
I thought that the TPA3124D2 may have got damaged by static so I replaced it with the the same result.
The circuit is powered by a 12V and 24V switch mode supply.

I made a sort of main unit that plugs in to the amplifier (see third schematic) which has the audio on it and uses the pcm2901 USB to audio chip.
This works fine except that it generates  the same clicking noise that the amp does and other low weird noises.
Just to be clear all these amplifier problems occur with or without the unit plugged in, and with a mic or audio input.

I'm wandering if I made the same mistake in both circuits even though the amplifier worked fine at first.

And I dont think its the PSU's otherwise the amp would have done this from the start.

Anyone have any idea?
Is it something obvious?
Thanks in advance.

(Edit woops double upload, first two is the amp, last is the contoller)

[Audioguru]

Your schematics have very tiny symbols and text. The images are backwards negatives (yellow lines on a black background instead of normal black lines on a white background so I cannot see anything.

[abdullahseba]

Your schematics have very tiny symbols and text. The images are backwards negatives (yellow lines on a black background instead of normal black lines on a white background so I cannot see anything.

Not sure why, they high res but here ya go.

[abdullahseba]

Hmm I figured it out - for anyone who might come across this thread...
Looks like I had serious ground loop issues with the test wiring, and I might have to use 24v to 12v dc-dc converter instead of two supplies.
http://www.rane.com/note151.html