Thanks, folks.
1. The springs came out the moment I saw them, before I even gave the Seduction its first listen. I'm an old pro, this was obvious for both microphonicity and why would you want an unnecessary piece of steel there, either?
2. Of course the top plate isn't what's microphonic - it's a resonator - but the tubes are mounted onto it, aren't they? No, now don't tell me it's the socket that is, not the tube. You must have a lot of time on your hands, Blackplate, and a Jesuit education for getting into dithering the details. Tapping on the top plate with a pen is like banging a drum on mine, and indicative of lower level effects affecting the noise floor badly in a delayed, distorted feedback loop from the speakers, and other environmental noise (my seduction is sitting on an airtube isolator for the latter).
3. The trans has no reason to get loose if the unit isn't being transported/moved around much...I did mention transport...it's the movement that will shake the trans around and then the mentioned mechanical disadvantage will loosen the screws. However, even if you don't take the Seduction anywhere (careful not to let 'er feel neglected...), there's still the fact that all transformers cannot help but generate some amount of vibration - and it's mounted onto that same top plate. Vibration isolating it is still a good idea and my fix addresses both issues.
4. I tube rolled 5 sets of tubes immediately after burn-in and settled on a set of 6922 JAN/Sylvanias for the *sound quality*, the most important thing for me. Your goals may vary. I'll fix the microphonicity if I have to to get the sound I want rather than compromise on that by using a tube that is less susceptible. A Russian pair was among the testees, and there's a fabulous but expensive Red Tip pair of 6DJ8's coming to me on a trade soon that will be an alternate - it's smoother and more alluring (borrowed briefly for the listen), but a bit less quick and detailed than the JAN...to fit mood.
5. I make my own "Tube Crowns" (not one of my products, I only make them for myself - not a profitable item handmade, see the attached pic of my completely rebuilt 60's Mac 240 mid amp in my triamped/active XO setup) from lead bars + ERS lining, foil outer cosmetic). Have compared them to the Mapleshade product (very nice, recommendable for those who cannot make something like this) and mine are rather noticeably superior. But I haven't made any yet for the Seduction, and would not use them alone, anyway, on a *phono stage*. I would have to add a shielding "veil" of some neat shielding material - I have a few types from a copper/nickel sputtered mesh to something that looks like your wife's "sheer" curtains, to a stainless/copper/unspecified proprietary something or other amalgam weave to work with in my stocks (sorry, proprietary sources - I do this for a living). This would make a nice see-through (for the "glow") shielding veil but I have only so much time on my hands to build this so it will have to wait while I try to pay the rent.
6. No need to feel inadequate, Doc. It is much easier to snipe the fixes than to do the orginal design, and I see lots of clever turns of layout I admire in this design. Joppa (IIRC) did a nice job here. Besides, every product that is to be profitably self-sustaining has to be built to a price point. Leaving room for guys buying the design to have some fun making their own changes and improvements is part of the game. Gotta leave room for those in hobbies. My congratulations meant, not criticism!
Modmad
