freestompboxes.org

Just got these from an eBay auction the other day, thought it was pretty funny. They're definitely Russian 6p6s tubes. Would've been a cool light show if I put them in my bass amp and biased like a 6l6gc. The one on the right is the same thing, but labeled realistic brand 6v6.

Ugghhh - Mike matthews and Sovtek strike again
bajaman

seem obviously not 6L6GC but I suppose it is possible the print was an innocent mistake (poor quality control).

Zombie thread alert!

Fake 6L6GCs are still doing the rounds.

TL:DR

Back story. My internet had been down for 12 days and I had an amp on my bench that needed a pair of 6L6GCs. I don't have enough mobile (cell phone) signal to use it indoors so was stood in out in the middle of the street (where the best signal is), in bright sunlight, with old tired eyes and only being able to read the description went for a matched pair of NOS Brimar 6L6GCs (well respected British company).

When they came I fitted them and of course they red plated. When I got my internet back read the description to see what I had actually bought. They were (poorly re-marked) 6N3C (6P3C as the Russian N is Pi I believe) and in the description it said not to use them at more than 375v and no refunds given if they had been red plated.

I contacted the seller saying that if they were genuine 6L6GCs they would operate at 450v. He said that they were ex UK MOD that he received as a box of 100 some years ago, with a spec sheet specifying 375v max working.

After a few back and forths I asked him for a copy of the spec sheet, and as we were getting close to the date where Ebay would step in (which I suspect was the last thing he wanted) and he gave me a full refund. Result!

During all this I learned a lot about 6L6 valves and all the variants and that after changing hands multiple times Brimar is still in business (brimaruk.com). I emailed the owner who not surprisingly was not at all happy about people using the Brimar trademark illegally.

Yo! I have the "Mullard" version of these! "Factory matched" pair in original boxes. I got them in the late 90's from a hi-fi shop in Chicago I used to work at - they were just hanging out in the stock room and looked pretty old even then. The boss was not a big tube fan, so we didn't really stock any tube stuff, so he was glad to give them to me or sell them to me extremely cheap, I can't remember which. Years later, I was trying to ID them, since I had figured by then that Mullard didn't make 6L6s like this, and that's when I found via another forum that they were Russian tubes that had been rebranded.
Subsequently, I found Shuguang in China was making a 6L6 that was very similar design to this - as this was the stock 6L6 Weber was including with their kits at the time (around 2007).
I'll post up some pics later on - I can show the "Mullard," an original Soviet and a Shuguang all side-by-side so you can see the similarities.

Those 6p3c tubes actually sound pretty good if you use them within their ratings. I've made a few amps that run around 400v on the plates give or take and these tubes hold up fine if they're biased properly. Only rated for 20 watts on the plate sort of like a 6l6GB or similar. I seem to remember they made an alarming mechanical pinging noise as they heated and cooled which might have been the metal inside complaining from being slightly abused. Would not put them in anything rated for proper 6l6GCs though, that's asking for trouble.