OK....this is the final set of pics from my EMT 240. I said I would take inside pics when I replaced the pilot bulb and made adjustments to the main springs, so here's the whole sequence for anyone interested or needed EMT240 info.
The inner sealed chamber that houses the actual gold foil plate. As you can see, it has two main springs that hold it up, and then side springs in the middle and at both front and back of each side to keep it from swaying too much and basically 100% suspended in the air.
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This is a close up of the bottom metal bracket, and you can see that now it is up about 1/4" off the fiber pad. Initially, the main springs must have sagged over the years, and that plate was touching the fiber pad, so any floor/room vibrations were affecting the main chamber. Now it is 100% floating. There are similar brackets at all the sides, and now all four have about the same 1/4" spacing from the fiber pads and outer case.
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Close up of the main spring.
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Close up of the adjustment nut for the main spring height/tension.
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Some of the main power electrical stuff (most of the actual amp/reverb electronics is not visible as it is inside the inner chamber, and also in each of the EMT262 amp sections, which are inside that metal housing right above, and what you see at the front of the unit, and where you adjust I/O levels and bass cut.
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Some adjustment pots...but nothing I messed with at this point.
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This is the replacement LED bulb and the new rubber feet I got (Peavey cab feet). Picked up some screws from Home Depot by eye, and they were perfect size/thread for the unit. so the feet went in like OEM, and even better, as they are beefier and little taller.
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Just a shot of the pilot light in its glowing glory with the new LED bulb.
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And finally, this is the "sandwich" I made to decouple the unit from the floor even more effectively than it sitting just on its rubber feet. It's a piece of 2"x4", with a rubber pads from a typical outdoor rubber doormat that I got at Home Depot. Just put a few drops of epoxy on either side, and glued them to the wood.
Then under that sandwich, I added a 1/2" piece of packing foam....a very rubbery kind of foam, not the Styrofoam stuff....and it doesn't compress 100%, rather it acts like a spring, so if I rock the unit, it just has this springy wobble to it, but it is firmly in place. There is a second "sandwich" also under the rear feet.
Works like a charm, and after a few days, the unit has settled into place so it's quite steady.
I used the small piece of cork at the one side of the unit, front and back, as shims to make level, since it sits on a carpeted floor and it wasn't perfectly level, plus the rubber/foam wasn't compressing 100% identically on both sides, since the unit has a bit more weight on one side....but it's set now.