Anyone try modern 6sn7 Shuguang WE type vs NOS RCA,Ken Rad

lowrider how far are closest outside diameter on your tube sockets from each other if that makes sense? My power amp has 3 6sn7 tubes up front and I have to use an adapter on the middle one. The OD of sockets is maybe a little less than 5/8 or 5/8 of an inch from each other and the adapter works to fit fat bottle between the other 2 mounted flush, it’s close and they almost touch.

I put Ken Rad vt-231 in it only ran in for a couple hours maybe it needed more time. I took them out added Shuguang and everything was airy with bass sounding correct. Ken Rads had reseeded highs bass was exaggerated just dull.  I’m going to run Ken Rads again but let them run all day they have been sitting up for years. The more I do this I may like this Shuguang better than all my other 6sn7’s. Maybe the Sylvania vt-231’s will change my mind. Glad when I find best tube and can leave it alone.

Who's the most trusted vendor to buy from? 

A prudent question.  I'm currently looking on eBay, although AliExpress is a good alternative if paypal is available.  All from China, I can't see that there is any organised distribution/dealer network.

Focused on one with 6,000 transactions, 99.3% positive feedback   That's for a pair of premium shuguang's, in a fancy solid looking box.

The box is a signal (information) that they are genuine, however defined.  I don't care for the box itself, pffftt.

@paulcreed  My amp uses 6 input tubes. They are in pairs from front of amp to back. Measuring outer diameter at closest position there is 1" between L & R tubes. However, only .25" between front pair, middle pair, and rear pair. 

Paul, it's funny you mentioned the sound of your Ken Rads. I'm burning in a pair of NOS from Vintage Tube and there are rolled off highs and no bass extension. So yeah, you need some more hours on those tubes.

@noske  Interesting, no dealer network. I would only buy the pair in the box, dont want any loose tubes from China.