Unfortunate about the Russians (especially for Ukraine). The Svetlana "Winged C" 6550 were some of the best sounding tubes I've used.

I had previously liked the GE 6bg6ga in my amp but I noticed there was another version with plates that were dead ringers for the well thought of GE 6l6gc. Well, except they were black instead of grey. My curiosity was piqued and since they are so cheap I figured I try them one of these days. Finally got some and after extensive rolling of inout tubes I can say you should should... use the RCA 6bg6a. Lol.

I mean, if you're willing to try a bunch of stuff to try to combat the darkness of those GE tubes you can get decent sound. The RCAs in contrast seem to sound really good with most of the tubes I tried. I used a tall bottle 7n7, tung sol black glass 6sn7, and a Brimar 6sl7 and all of them sounded good. Different from each other to be sure but all good. In the end I settled on the Raytheon 6f8g with the T plates as the best all rounder.

I had always heard that the 6bg6 and 807 were essentially the same tube. The RCA 6bg6ga, unlike the GE, do look remarkably like the 807. The spec sheet would have you believe they are the same tube. The RCA 807 has alway had a good rep. If they sound like the 6bg6ga then I agree. Of course you can get the 6bg6ga for single digit dollars as opposed to the double digit 807.

So yeah, RCA 6bg6ga is a great tube, highly recommended. and it's cheap!

Can I use a globe 80 rectifier in my FireBottle KT88 SE amp in place of the 5U4G?
Thanks!
Chris

I have a question: I have a beautiful red Inspire Fire Bottle. I came across a vintage 5Y3 rectifier tube and I'd like to try it out. But I don't have any of the compatible power tubes listed in the manual (6F6, 5F6G), I have 6550's and KT88's. Will it be bad if I put in the 5Y3 with the KT88s?

It will work fine. You just won't get all the potential power out of the larger tubes. However, you may find a combo that you prefer sonically...