Anyone try any of the late model Sylvania 5881 JAN tubes that are starting to appear on the market? I Noticed that these keep popping up on Ebay in small lots and are the black plastic base with green lettering. True NOS in unopened generic white boxed military packaging with black stamped lettering. Great bargains to be found from a few different vendors. Someone must of uncovered or discovered and released a large lot of these somewhere or are being released at some govt. auction? I purchased four unmatched and untested brand spanking new off Ebay for under $90 I cant wait to test them. Hopefully we have close enough matching for use as a quad, or at the very least get a pair outta the deal. Otherwise its mod a PP amp or SE use. I think these baby bottle beam driven power tubes might be pretty decent in 5881 Marshalls such as JCM 900's or perhaps a Mesa Lonestar. I will let ya guys know , but I am very curious to hear what others have discovered with these tubes. I also have noticed numerous Raytheon 12Ax7's and made a purchase of supposed NOS tubes but looking at condition of the pins and such I doubt true NOS but likely used test as new like they so often describe as being NOS.... These seem pretty quiet and balanced but not real powerhouse. I am happy with how transparent and resilient they are against microphonics. Especially for a long plate. I also scored two Telefunkens from n old 1959 console high fi. These are original tubes with ribbed grey short plates and they are excellent. I am using one inside of a tweed champ circuit and it is nice! So what beautiful gems have others scored recently? WHat about those SYL/Jan 5881?