Pair of JJ ECC802s / Hi-Performance 12AU7 Preamp Vacuum Tube

Only first day with the tube so I can't comment on longevity. The tube is an improvement over the Chinese tubes my amp came with. Bass is more noticeable , sound stage is larger, seems more detailed and full sounding.I'd say a 15% to 20% improvement over the Chinese tubes. Using hd 6xx paired with a xduoo ta-03s. These two are a perfect match imo. The tube helps tone down the brightness 6xx can have and makes it more warm.

One tube went out in under 3 weeks' time. Sound was good till it wasn't.

JJ ECC802s, long plate, hi performance,12au7. I ordered the pair from TubeDepo for $27+sh&tax. Came matched, gm triode1- 60 and triode2 -60 on both tubes. Using them in an Xduoo TA-20 balanced headphone amp with Hifiman HE400s, Senn HD6xx and Superlux HD681 headphones.Only have about 2hrs on the tubes, still in the breakin period. First impressions: fuller sound, more musical, widened sound stage, extended mids and definitely more bass then the stock 12au7 tubes that came with the amp. The headphones are on the clinical side but I can hear the bass boost these tubes add to the music. The tubes are a bit muffled fresh out the box compared to the stock tubes (stock tubes are just marked China 12au7 and are bright). I've read the jj ECC802s will open up as you get 20-50-100 hrs on them so going to cycle them for a few days and see how they open up.At this price point there is nothing like these. I'd definitely suggest giving these a try. NOS Long plate ECC82 tubes from the 1950s that have 5+mm longer plates like the JJ Ecc802s are modeled after are $100+ per-tube. $27 for the pair of JJ tubes is a steal. These are about 7mm taller over all than standard 12au7 tubes so you might need to watch your clearance. Some tube guards might not clear these tubes. (Check the pictures)Update #1: About 25hrs on the tubes and the vail has been lifted. The original muffled tone is all but gone. The tubes have become brighter but more detailed also.Update #2: December 6th 2020, About 75hrs on them. Very clean highs, detailed mids, bass is tight, they just continue to get better. I've ordered a matched pair of Psvane 12au7-S and a pair of Psvane Cossor 12au7, black carbon crystal tubes. Once I get them burned in I'll do another update with comparison also. There are a lot of NOS tubes out there you could chase but I'm going to stick with new production tubes for this comparison.Getting back to the JJ Ecc802s. For an inexpensive and very affordable tube they are definitely worth getting. All the other new production tubes are short plate and shorter glass over all. (Check the pictures) The JJ Ecc802s, have longer plates and are taller. This should provid better cooling (they are absolutely cooler to the touch than standard 12au7 tubes) and they should last longer than standard 12au7 tubes.Update #3: Dec 10 2021. Got the Psvane 12au7-S in. They sound very solid state-ish compared to the jj ecc802s. Good for critical listening, very precise. Rhianna Giddens amazing voice and her banjo sound great on them. Bob Dylan’s Witmark demos or any acoustic guitar if you like clean and precise. EDM would probably would sound great thru the psvane 12au7-s tubes but hadn't had a chance to test that theory. One of the Psvane 12au7-S tubes failed at about 10hrs. It started hissing and sounded noticeably quieter then the other. Swapped them in the amplifier and the problem switched sides. Currently talking to the seller to see if they are going to refund or send out another set. So the jj ECC802s are back in the amp.I like the jj ECC802s tubes so much I decided to order another set for back up.Given my setup. Both the Xduoo TA-20 hybrid headphone amplifier and Sennheiser HD6xx/650 headpones are on the clinical/brightside so the jj ECC802s adds some tube-ness, bass, darkness back in.Bands and songs that sound great thru the jj ECC802s are any of the blues greats, BB King, John Lee hooker, Gary B.B. Coleman. Also, JJ Cale, Eric Clapton. Look up the band, Hillbilly Moon Explosion and the songs "queen of hearts" and "my love for evermore". Jass is amazing also. Anita O'Day, "No Moon at All" and "A Nightingale Sang in Berkeley Square" are sweet thru the jj ECC802s.