There is a reason why the British tubes have such strange denominations. The British could not compete pricewise with the US factories. Instead of producing the same tube with the same denomination, they invented different nomenclature to confuse the issue and avoid direct price comparisons...

The GE 6AS7GA is overpriced. You shouldn’t pay more than $25 + shipping for a NOS pair. Used tubes you can get for $10 each + shipping.

I am using Ken-Rad 6C5 with different power tubes but I really like the K-R 6C5 tubes. These tubes can still be found a real bargain prices. Sometimes they are a little rusty but it doesn’t detract from the sound.

What’s so nightmarish about it lol?

Yes, you are right - GTB.

I use socket savers in all sockets and they lower the temperature of the chassis. In addition, I use two inexpensive 4”USB powered fans - one blowing on the transformer and one blowing on the tubes. Usually I measure the temperature on the transformer housing which tends to get the hottest. The...

Are you using 2 or 4 6S2S in the 6SN7 socket?

Looking at various 807 tubes: This is a GE labeled tube that says Made in Italy. Could it be a Fivre? https://www.ebay.com/itm/334391949529 Also came across these GEC KT66 on eBay UK: Is this GEC KT66 possibly at a bargain price...

Glad you like them. IMHO this tube is a sleeper and deserves a little recognition.

https://www.ebay.com/itm/385322783347?itmmeta=01HXYNKH55K3YV2EM0JMDH3F8C&hash=item59b7071273:g:Nz8AAOSwKYZjrrKN&itmprp=enc%3AAQAJAAAAwMS2ukKLyn3LSsIsk5sSIZEAMRkz69b8IUcI7%2BdWZ0qrlepYoCrnvNgLaAEz6Kr3kPijsYMqHmIYjj%2BLO7DXMJ4MD7KEBDCeizJMtkOj6akLOjF6bRkL8rOzaMHaQhhoqR0tLvC7UWBIr0CPwCSHjOoz%2F4KplL...

This is from the list provided by Triod750. It identifies the tube and perhaps indicates a certain time period when these designations were used, but we still don't know the manufacturer.

ZA4138 Triode 6J5G CV1932 This must be the complete code

Are there other markings on the tube?

Tried to capture the beauty of a 807 with a long exposure night shot: This is a Russian made Ulyanovsk tube from September 1974 masquerading as a US made Philips. All the markings were removed including the date but a thoughtful comrade worker wrote the date inside the tube on the top mica...

Originally it seems to me that most Soviet tubes came from Svetlana in St Petersburg. However, it was too close to western Europe during World War II and the Russians moved vacuum tube production to very far away places.

https://www.ebay.com/itm/386961076028?itmmeta=01HXQ7HEJGQJGKAWBYPAZX3T2Y&hash=item5a18ad6f3c:g:Ju0AAOSwsCJmK7h~&itmprp=enc%3AAQAJAAAAwO%2Ffi9kk%2F1v%2F2GNsUs70U9LW2meHARK7yM7w4AX1C0YMGeW1Pp6qk6qISlE4JJZevK8kae8z2%2BNu7NQUf8gXK3EiMyYBy9KcH10EFg9sizUP037X5BWu0lCYVCbWna5r7Q10bDmFnZKsgs%2BMgbWpNaDzX7...

Regarding the 6H30Pi the real super tube is supposed to be the 6H30-DR bit I haven’t heard it - too expensive for my taste. I have the other 6H30 variants and the Pi sounded the best to me. I am sure that you know this but just to clarify: There is no such brand as OTK of Russian tubes. It is...

I give my vote the the sibling of 6BX7 - the 6BL7.

Ask Deyan.

From my perspective any kind of sealant would interfere with metal to metal contact.

You get points for finding the hidden symbolism lol.

This is what I use instead of deoxit: No fuss no muss - just a quick scraping with the thin blade on each tube pin until they are shiny. Victorinox or Wenger - whatever I find first in my drawer. This is based on a scientific paper from the 40's that I read a long time ago comparing different...

It's a Fivre...

Agree, but it works. Speaking about tubes, has anybody tried the 6TP ? (807 variant)

If you don't have a dedicated preamp out you can always use the headphone jack. On those amps that have a four pin XLR for headphones you can get an adapter and use this for preamp out as well.