Tesla NOS E88cc gold pin--PRICE REDUCED!

NOS Tesla E88cc gold pin; low microphonics; tubes recently tested by TC Tubes LLC "as new" using AT1000 tester; Buyer pays shipping and Paypal fee, unless paying by friends and family;  I have four to sell and I am asking $30/each.

Email to me from TC Tubes LLC:
"The 6922 type is a bit tricky to grade due to the very high gm of the tube. This makes a small change in bias result in a large change in current draw. This tends to make the differences between triodes dramatic. Especially when run in fixed bias mode--which basically all tube testers do. Interestingly, almost no audio circuits do this. They almost always use cathode bias, which tends to minimize the difference between triodes.

So, the quick and dirty criteria is 10mA and 10,000Gm or higher is the place to be with these. This is based on the RCA spec sheet. It's a little confusing since this is significantly different than the scores generated by the Amplitrex AT1000 testers (in terms of % values). I've interacted with the designer of the Amplitrex about this and he agrees with me that 10mA and 10,000Gm should be considered a solid tube. Even though the AT1000 will tag 10mA as about 66%. My 10mA and 10,000Gm benchmark was arrived at by running some tubes at the RCA spec (which is cathode biased) and then comparing those tubes that agree precisely with the RCA data sheet with the scores they generate on the AT1000. A tube that matches the RCA spec sheet ends up at 10mA and 10,000Gm.

Anyway, the good news is that all of your 6922 tubes test at or above 10mA and 10,000Gm. So they can all be sold with confidence as testing "as new"."