Sounds like these grounding boxes do make a difference in your system, I have always had doubts on how useful the grounding device is. The Puritan grounding system is a lot more reasonable than CAD. I’ll give them a try first in future.
Enjoy your lunch or breakfast on a tiny table 
The next time you come to Paris send me a message because I live in Paris…
Very kind of you, Fred. Thanks. We’ll be in Montmartre this morning, then walking (slowly) around the center without specific plans, that is my usual and preferred way to visit a city. It’n not my first time here, though.
Any audiophile advice around Louvre/Royale area?
Unfortunately, this area is not very audiophile. I live in the 17th arrondissement, 10 mm from the Arc de Triomphe…And my wife speaks Italian perfectly. So see you next time in Paris
Note @luca.pelliccioli is using different devices to address earth ground (puritan) and signal ground (CAD device) on each particular audio component. That is fine. But also note CAD recommends that you do not use the same grounding device to connect both an earth and signal ground on the same audio device. Just wanted to give a heads up on not mixing earth and signal ground on the same audio component.
You are right. And things seem to be even more complex. CAD recommends not mixing in the same Ground Control device, Signal and Chassis ground. My scheme connection was suggested by Scott himself, who wrote me how tu use his products in my system.
Puritan mentions a third ground level, called Earth, that GroundMaster and GM City are able to manage in conjunction with the PSM156 conditioner, more related to the existing ground in a home circuit (or connected to a dedicated specific rod).
http://www.puritanaudiolabs.com/wp-content/uploads/2022/04/RouteMaster-Usage-Notes.pdf
I’m wondering how power cords should be considered between the three types, guessing they are more in the Earth ground camp.
Stealth recommends in fact a full loom of Dream cables to manage grounding issues, too.
Shunyata, EntreQ, Nordost and many other brands have their products and philosophy on this argument.
MSB is also recommending a ground connection between DAC and Amp, that I’ve tried and I can assure it’s really effective.
All devices I tried to manage these ground solutions brought the same benefits, sonically speaking: blacker background, depth, clarity, openness without any alteration to tonal balance. At least in my system and to my ears.
This grounding business is getting crazy! I’ll keep it simple by keeping it within Puritan family. At least it can coexist with PSA family.
And I’m getting great results star grounding almost everything to a Synergistic Active Ground Block SE and having two electrician-installed ground rods at my service panel.
There are definitely benefits to observing better grounding practices and it doesn’t necessarily require expensive gadgets to begin–you can start with some wire and a male AC plug, connecting chassis grounds to the ground prong on the plug to access house ground. If you like the results, go from there…
Sorry for my ignorance, I’m trying to learn something more: couldn’t power cords themselves be considered a star grounding if the components are all plugged into the same power conditioner/regen?
Can’t grasp the meaning of chassis vs earth ground path, while signal ground it’s easier to understand. I mean, the third pin in every IEC inlet is not directly connected to its own chassis for safe grounding purpose? Even if a ground lug could permit a direct and cleaner ground way, there alway is the power cord ground wire that should do the same job, isn’t it?
The Puritan site explained going back in time, the signal ground and chassis ground were all one and the same since the incoming power cord gave a direct connection of both to the ground pin of the power plug. However, modern components sometime use assorted grounding practices which result in “lifted” ground levels (no detail explaination on this).
okay, even I believe in the theory, why do we need grounding devices selling for $$$ to level the grounding? It should be a very simple cheap fix to cure the issue. If the sonic benefit is from lowering the ground to the same level, the improvement should be all the same. This is the part I do not understand, just like external clock business.
I use CAD Gound control devices. The Why question gets answered quickly when you use them. I can’t think of anyone who has tried one saying “nope, doesn’t work, it’s going back”.
It just like any other audiophile tweak, and do not think about why. I should know that better. 
As much as it seems like an advertisement for them this video does good job explaining the science.
yes, I remember watching it, and I will order GroundMaster City and RouteMaster to try out. Thanks!
The CAD website has a good white paper explain the basic phenomenon and science of signal ground and earth ground and how they impact the sounds we hear. I think it is has “background paper” in the title. I can’t provide a direct link because it is a PDF on their site.
You should be able to post the URL.
Thanks, I’m reading it now (better than Sunday morning newspapers):
My posting skills are clearly deficient 
Can’t say what causes it, but last set up is sounding really… NICE!
Need to let it burn in but seems to improve the sound hour after hour, and I haven’t still played with the collar. Very promising.
Don’t know why… and frankly don’t even want to know… just listening to.
Sounds like you better take some real good notes on this one.
Enjoy the music my long distance friend.