Tube Data Sheet Locator. Warning: Substitutes are given as a guide only - please refer to original manufacturers data sheets to ensure that a substitute is safe and appropriate for your application. They do look very much like the same tube but so do an RCA 12at7 and 12ax7. It may be the Gold Lion 6V6 has different support rod and spacer material with a different coating on the plates than the Tung Sol. It's anyones guess without the production data. I guess the only way to tell would be to compare them in the same amp for any audible ... I’m trying to find good sounding 6SL7’s for my EAR HP4 by identifying great sounding 6SN7’s and then trying to locate a corresponding 6SL7. I’m hoping the desirable qualities of the tubes will carry across to tubes in the same family. I just got a pair of Tung-Sol 6SL7’s with round plates ... Tung-Sol is a brand owned by the American New Sensor Corporation and manufactured at the Xpo-Pul - Reflektor factory in Saratov, Russia. The Tung-Sol 6V6GT beam power tetrode tube was the preferred OEM tube for vintage Fender Tweed and Deluxe amps. View Tung-Sol product datasheet at HeberTech.com.