JJ Electronic New in Box Gain Matched Pair s Tesla 12AX7 ECC83-S Vacuum Tubes

Ordered a matched pair of these vacuum tubes, has definitely improved the imaging, clarity and bass definition on my Project Audio Tube box S2.

Unfortunately the valves are broken and therefore did not resolve my issue. I have had to buy another set.

Came nicely packaged in a foam insert and cardboard packaging. Slotted into my Blackstar amp nicely. Worked first time, nothing needed adjusting. (Not sure if it needs too) only time will tell how long they last.

I had a gift card so I took a chance on these vs a dedicated supplier. These were fulfilled by Amazon and had no extra packing. The poppadoms I ordered actually had better packing! Still, they arrived intact and working so that's okay. I own a valve tester and one valve tests internally matching, and the other does not, so can't match the first tube. The item is not 100% as described. If you've been advised to buy a gain matched pair, but don't know why, here's a brief explanation. These are dual triodes, which is to say each glass envelope has two gain stages. For some applications you want the two stages to match. These are sold as a matched pair, so you'd expect all four triodes in the two tubes to have the same gain. See photo's of test results. They are however cheap. The specialist supplier wants £20 each + VAT + postage + VAT on the postage vs £41 free delivery. You pays your money, as they say. FWIW I'm keeping them. Averaging 5* 1* = 3*

Am using these in my hi-fi pre amp have tried all sorts forget mullard and other so called top brands these run rings around the lot I'm fussy but these I love great improvement cannot fault they are also getting top ratings around the world highly recommend.