[Designsfx]

Not sure who made these but there is a 2C22 datasheet from RCA.
http://www.r-type.org/pdfs/2c22.pdf
According to Radio Museum, 2C22 is developed by Ken-Rad, https://www.radiomuseum.org/tubes/tube_2c22.html

It seems that KenRad was the common denominator for 7931/2C22 but I’ve also seen CV3601 branded Haltron that is supposed to be the same thing (though not in large numbers). I’m going to patiently wait for results from @budburma with regard to its use in the Lampizator though- I’ve gotten itchy on tubes/adapters before that didn’t meet expectations. Hopefully they will shine!

 

[Wes S]

6S2S are in the amp and sounding mighty fine.

I am most definitely a fanboy of Russian tubes, and I am happy to have these in my collection. Got to love cheap tubes that sound incredible.

 

[Designsfx]

To all that shop with Billington- I just downloaded the recent 2024 catalog and while reviewing I’m seeing “sorry NOT identical pairs or sets” on almost everything I’m interested in. As I’ve not placed orders with them before how does this system work and how “persnickety” do they get when asked to assemble quads of tubes? (by model/brand/years). Are all purchases put together as a “mixed bag” or can you actually end up matched sets/quads? Reading this created a picture of wildly varying singles showing up. What have your experiences been?

 

[leftside]

To all that shop with Billington- I just downloaded the recent 2024 catalog and while reviewing I’m seeing “sorry NOT identical pairs or sets” on almost everything I’m interested in. As I’ve not placed orders with them before how does this system work and how “persnickety” do they get when asked to assemble quads of tubes? (by model/brand/years). Are all purchases put together as a “mixed bag” or can you actually end up matched sets/quads? Reading this created a picture of wildly varying singles showing up. What have your experiences been?

Treat the catalog as a guide The more expensive the tubes/bigger the order, the more likely you'll be able to get pictures/more info.

You're going to need patience when dealing with Billington, but I estimate over 50% of my tubes have come from Martin and crew.

 

[MJS242]

Anyone have experience with 6C5 to 76 adapters? I've had a set of adapters for a long time now but I've never tried them until today. When I did, the 76 tubes lit up very quickly (and very brightly) and there was loud buzzing in both channels. I didn't continue to run the amp because that didn't seem right to me. I've had good luck with 6C5 to EF86 and 6C5 to 6SN7 adapters in this amp.

 

[g0ldl10n]

Anyone have experience with 6C5 to 76 adapters? I've had a set of adapters for a long time now but I've never tried them until today. When I did, the 76 tubes lit up very quickly (and very brightly) and there was loud buzzing in both channels. I didn't continue to run the amp because that didn't seem right to me. I've had good luck with 6C5 to EF86 and 6C5 to 6SN7 adapters in this amp.

Are you sure those are 76s and not something like 27s that run on 2.5V @ 1.75A instead of 6.3V @ 0.3A, only reason I could see this occurring.

 

[CAJames]

Anyone have experience with 6C5 to 76 adapters?

Yes, and they work fine for me. FWIW I get my ebay adapters xulingmrs whenever possible. I've had very good luck with them, I can't say that about other ebay adapters.

It might be a problem with the tubes, although it is unlikely that 2 tubes are bad in the same way.

 

[CAJames]

To all that shop with Billington- I just downloaded the recent 2024 catalog and while reviewing I’m seeing “sorry NOT identical pairs or sets” on almost everything I’m interested in. As I’ve not placed orders with them before how does this system work and how “persnickety” do they get when asked to assemble quads of tubes? (by model/brand/years). Are all purchases put together as a “mixed bag” or can you actually end up matched sets/quads? Reading this created a picture of wildly varying singles showing up. What have your experiences been?

Yeah, you're going to have to email them regardless, and my experience is Martin is happy to answer questions about what exactly they have in stock. Like leftside says, it takes patience, but I've also bought a lot of tubes from them and they've been great (both the tubes and dealing with Martin).

 

[triod750]

Anyone have experience with 6C5 to 76 adapters? I've had a set of adapters for a long time now but I've never tried them until today. When I did, the 76 tubes lit up very quickly (and very brightly) and there was loud buzzing in both channels. I didn't continue to run the amp because that didn't seem right to me. I've had good luck with 6C5 to EF86 and 6C5 to 6SN7 adapters in this amp.

You could try to make a Faraday's cage from aluminum foil around each of the two tubes to check if the hum goes away. Sometimes you need to connect the foil to the ground. I have done this in another amp and the tubes became dead silent. I don't know if it works in La Figaro but it is easy to try. You just wrap the foil loosely around the tube and socket and 'close it' on top...

 

[MJS242]

Are you sure those are 76s and not something like 27s that run on 2.5V @ 1.75A instead of 6.3V @ 0.3A, only reason I could see this occurring.

It looks like a 76 as far as I can tell. Ordered from eBay, came in a Tung-Sol 76 box, has a 76 on the base. Correct number of pins for a 76.

 

[MJS242]

Yes, and they work fine for me. FWIW I get my ebay adapters xulingmrs whenever possible. I've had very good luck with them, I can't say that about other ebay adapters.

It might be a problem with the tubes, although it is unlikely that 2 tubes are bad in the same way.

I wasn't sure where I purchased the adapter since it's been some years, but I double checked and it was from xulingmrs via ebay. I tested four tubes and they all performed the same way.

 

[MJS242]

You could try to make a Faraday's cage from aluminum foil around each of the two tubes to check if the hum goes away. Sometimes you need to connect the foil to the ground. I have done this in another amp and the tubes became dead silent. I don't know if it works in La Figaro but it is easy to try. You just wrap the foil loosely around the tube and socket and 'close it' on top...

I'll give that a try. This is probably amp dependent, but does anyone know if a 76 should "turn on" that quick and be so bright? I've never seen that from any tube.

Thanks all!

 

[CAJames]

I'll give that a try. This is probably amp dependent, but does anyone know if a 76 should "turn on" that quick and be so bright? I've never seen that from any tube.

Thanks all!

The 76 tubes I’ve used have not behaved like that. But, now that I think about it, very early on I might have had a couple of Tung-Sols that behaved very strangely. They were part of a grab bag and I quickly moved on, and don’t remember the details. So there might be something with TS 76s that is a little funky. I have a quad of RCA “silver meatball” 76s that sound really nice, but I prefer Sylvania Type 37 when I’m in a UX5 mood.

 

[triod750]

Some tubes are 'quick heaters'. Not unknown with Philips 7- and 9-pins. I think I have a pair of 6L5G that acts this way too.

 

[g0ldl10n]

It looks like a 76 as far as I can tell. Ordered from eBay, came in a Tung-Sol 76 box, has a 76 on the base. Correct number of pins for a 76.

That is definitely strange behavior.. only time I have had that occur to me is when I applied too much filament voltage on a tube rated for less - shines like the sun and can often times hum loudly. You don't happen to have a pair of different 76s you can test with, do you?