Em field from tube amp rack style mounting

[Thurgood]

em field from tube amp
Hello all: Due to size constraints and overall economy of space (and convenience) I ask to you fine folks: Will the EM field of a marshall dsl amplifier interfere with rack mounted Comp (vla and older Quadraverb) if mounted close to one another? By close I mean 2.5" (inches). I need to stack the rack units atop the marshall head. I am giving 2.5" of air space between the head and the units for cooling (another issue). I have rarely combined amplifier heads and efx in the same rack unit. I did once have a Mesa 2/something 90? with a lexicon pcm and power conditioner etc in an anvil type case and it was fine.
Note the comp/efx and DSl will share the same power source but will probably not be connected directly. EFX and comp will be "outboard hardware" for other uses. I do realize potential (lol) ground loop issues) but my main concern before I start building stuff is the "buzz factor" inductance etc..?? Helps please. Thanks in advance.

[Enzo]

Set them up there and find out.

[Thurgood]

Enzo, thats probably what is gonna happen. The truth of the matter will probably be some sort of ground loop. As I stated earlier I have racked amps with processors without trouble and "stacked" (read piled) these thing on top/under one another without problem. I am just LAZY b/c to do what I plan means a good bit of unplug/re-plug test, unplug move etc.. Maybe I should have phrased teh question "are marshall dsl's notorious for a huge emmitence?. I appreciate your prompt response, thanks.

PS: My sinus headache and aggrevated bad vision are keeping me away from my current 5e3 build so I am occupying my time with something not so taxing to my eyes and head. I guess I should be careful for what I wish as this may be an even bigger headache. . Be Well All. WS

[Enzo]

Ground loops don't depend upon being stacked, they occur when grounds are connected together that have different potentials. That can happen with signal cables, but can also happen through rack rail ears.

Stacking something over a tube amp, I worry more about the power transformer magnetic field coupling into the gain circuits sitting atop it.

I had a customer bringing me his DJ mixer that hummed bad, but it worked here. I sent him home with it and it still hummed, so I invited him to bring the whole rack in. We found that he was sitting the moxer right on top of the power amp, and the amp PT was coupling into the mixer. All it took was moving the amp a coupole inches away down the rack. For some reason he didn;t have the amp at the bottom.

[Thurgood]

Thanks again. I get the potential ground loop issue ( that could arise even if the amp etc were across state lines) EM and heat are my issues. I will craft a "riser" today that will provide an approx 3" airway betweeen the head and efx units. That should do it. I did place the head and efx right next to one another (front to back) for test. No hum. So I should be ok with the EM issue and the grounding seems good at least from what I could hear at low volume (late at night so I could not open the amp up a bit) We shall see what this day brings. Thanks for your input. Now off to shoehorn the 5e3 board into the chassis. oompa loompa hands. WS