I decided to post my updates here:
Got this set of gold pins Sylvania Gold Brand 12at7WA
https://scontent.xx.fbcdn.net/v/t1.0-9/17021429_1595234603828034_5238115527356905272_n.jpg?oh=c84fb2...... and i must say this is the first tube that i really like compared to my Telefunken ECC801s. What a great experience, this Sylvania sound is something special, i think i have more flow, definitely more bass and while the top end is not so extended as with Telefunkens i still love the highs of Sylvania. very comfortable tube in my system. I think the gold pin version of Sylvania GB is rare, but still not so expensive as Telefunkens.
Now i’d like to replace my power tubes:
https://scontent.xx.fbcdn.net/v/t1.0-9/15826550_1525676917450470_2696563606639229955_n.jpg?oh=a47736...Telefunken E84L which i’m uning now with those Sylvania preapm tubes.
So the question is what can be really good as a direct replacement?
What about late 50s, early 60s cylinder "no hole" plate RCA smoke glass 6BQ5 tubes?