Mod advice needed for noise

[amc32]

This inquiry isnt related to another thread that I have began. I have a class D massive amp that has what seems to be excessive floor noise. That is still present when gain controls are high or low. I have verified that the ground sheild of the rca's and power supply transformer secondary center tap is common. With a resistance of 220 ohms.

My question is there a mod that I may add internally to the amp to help reduce this noise?

Iam using a jcv head unit on my test bench as my reference not an ipod and an regulated powersupply (pyramid 50amps max. with voltage and current meters)

[Perry Babin]

Noise isn't typically a problem with these amps (clone used by power acoustik and many others). Does the noise decrease when you switch from master to slave?

Can you hear the noise through a woofer?

Does the output at the speaker terminals have a lot (more than a volt) of high frequency noise with a load connected?

[amc32]

dc off-set at speaker terminals is 1.8volts. There is no master slave switch. This a 3000.1 model. Dc offset remains the same regardless of gain and/or sub-sonic controls. But when installed in car it has more floor than usual. When I short rca shield to transformer tap the noise is greatly reduced but still a little bit there.
Any suggestions?

[Perry Babin]

It doesn't need modification, it needs to be repaired.

Precisely what model Massive is it?