“TAD” Tubes

<<tad dif build>> correction, look near identical to all other 6550;s
That said, I can attest that each lab 's 6550's/kt88 (same tube) will vary ever so slightly in sonics, The ever popular Gold Lion 6550's did not meet the sonics that i found in the SVET 6550's. 
Next year I will go with TAD's and report back how they compare to my testing in the Defy7.

I need to get with amplified parts and see about a  return <<if needed>>>< I'd hate to be stuck with 12 tubes that do not at the very least match the Svet's. 
My hunch is they will match Svet's in bass/mids , and hoping surpass in the highest registers. 

just doing some research on TAD's  site,,so started cking out all 3 6550 offerings
$55, $70, $100
last i cked out the $100 offering and read this in the descript

<<careflly selected from SVETLANA's production>> 
Bingo
there you have it
TAD = Svet.
and i thought maybe,,,too funny.
Svet's are the <<real deal>> 
I'll just hang with Svet's , why change things up, the Svet's  have a  nice sonic resolution/balance.
I'm skipping the TAD
 https://www.tubeampdoctor.com/en/6550c-svt-tad-premium-matched-sed-6550c-winged-c?c=92

Just some general info: There are no SED, Winged =C=, Svetlana tubes, currently in production.     I really liked them (bought from Upscale), but- the St Petersburg plant burned down, years ago (along with it’s equipment) and SED closed the doors.     New Sensor bought the name (ONLY) and is manufacturing their version in the Sarartov, Russia plant.      Some info from a reputable dealer:  https://www.thetubestore.com/winged-c-sed-6550c                Try contacting known to be honest tube mongers, like the above, Brent Jessee Recording, TC Tubes or Upscale Audio, for knowledgeable info, as to whether they are, "the very same exact tube."      An opinion/observation regarding the new version:  https://www.tubesandmore.com/comment/2577/report                                   Compare the plate and getter construction, to the above (original Svetlana 6550) pic, here:                   https://www.ebay.com/itm/PLATINUM-Matched-Quad-4-Svetlana-6550C-tubes-Russia/184570896793?hash=item2...       Caveat emptor (just sayin')!

Find a picture in which the GE 6650's plate construction, resembles that of the TAD version.       GE:  https://www.google.com/search?sxsrf=ALeKk008s9IFOesJfnELbxiV6qQDoek0rQ:1607987542896&source=univ...    TAD:      https://www.ebay.com/itm/Factory-Matched-SEXTET-Tube-Amp-Doctor-TAD-6550-6550A-KT88-GE-6550A-Remake-...      TAD mentions the GE's triple gettering.     If they have it; it must be the world's weakest, as zero side-gettering shows in any of their pics (haven't seen any up close, however, so: an assumption, on my part)