Dash speakers white noise

2017 sequoia jbl
I bypassed the factory amp using a 5 channels amp.
Dash left and door are on channel 1.
Dash right and door on channel 2.
Rear left surround and door on channel 3.
Rear right surround and door on channel 4.
Sub on channel 5.

Currently on stock speakers.

Radio: joying sc9853i android
Amp: cerwin vega cvp2500.5D
Wiring kit Knukonceptz 4awg ofc
Stinger 4000 series rca 3 sets

Ground amp to, sanded, factory point under passenger seat.

Gain set very low using dso138 oscilloscope. No clipping.

Problem:
Im having what is think is white noise, coming through the dash speakers. When the radio is not playing any source. I can mute the radio and the noise will still be there. The radio have the sleep mode or delay turn off and enter sleep mode. About 30sec or so. So if the key is out of the ignition, the amp is still ON. Since the radio hasn't enter sleep mode, yet. During this time you can hear the white noise. Only when the amp is completely shut down, then the noise will stop.
I may need to change the amp turn on to acc wire instead of using the blue amp turn on lead on the radio's harness.

Is this a ground issue or an amp floor noise?
Is it possible to get rid of?
Is the amp crappy?

I did not have this problem when the factory was used.

 

Check the resistance from your amp ground point to the negative battery terminal. Make sure to account for the resistance in your wire leads.

Did you run the amp power near any signal wires?

 

Power wire ran from battery to driver's side floor. Rcas and amp turn on wire ran from passenger side floor.
They dont meet anywhere near each other.

 

That should be good then.
Check the resistance on your ground point to eliminate that.

If you have a spare amp i would swap it out and see what happens. If not, you might want to try to buy one and return it if it doesn't fix the problem. If that still doesn't fix it, then its your headunit.

I couldn't find anything on the head unit. What voltage is the head unit putting out through the rca's? You have the equalizer set to completely flat and any/all enhancements are turned off?

 

Ive did some process of elimination and determined i either have a faulty amp or just poorly built amp. Or combination of both.
I thought maybe the HU was producing rcas noise.
So, i unplugged all 6 rca lead from the amp.
Noise still there. No signal from the hu to the amp whatsoever, and it still there.
So, next i disconnect the Ground cable from the amp, while the amp is ON. Noise still present.
The amp was still sending noise to the speakers. Only when the amp is completely off, then the noise went away.

So it's the amp. I've arranged for a return and refund. Which the seller was happy to help.