Chassis and ground

[Prune]

Consider the following setup:
DAC is housed in one chassis and power supply in another, and both are put in a bigger chassis; also, a ground loop breaker is used to separate signal ground (10 ohm resistor paralleled by a small capacitor to pass high frequencies, and two antiparallel diodes in case of large fault currents) as I've found that it solves ground loop problems.

Question: should all three containers be grounded? Should all be grounded at the same point, or should, say, the DAC inner chassis be grounded after the ground loop breaker (at signal ground)?