The 12SN7 + adapter cheaper still, the same tube with a 12V heater voltage.
You can run them without the adapter and they may be fine.
I was very surprised as the 6H12C is a very rare tube, they don't turn up that often.
The 12SN7 + adapter cheaper still, the same tube with a 12V heater voltage.
You can run them without the adapter and they may be fine.
I was very surprised as the 6H12C is a very rare tube, they don't turn up that often.
Interesting, I didn't realise that there was another Russian tube besides the 6H8C/6N8S and 1578 that are electrically similar to the 6SN7. Am I right in saying that this is like a 0.9A version of the 6H8C? If so, I should be able to use it on my WA22 since it can handle the ECC32 right?
X2. That's basically all what I am using in my WA5-LE now.

Interesting, I didn't realise that there was another Russian tube besides the 6H8C/6N8S and 1578 that are electrically similar to the 6SN7. Am I right in saying that this is like a 0.9A version of the 6H8C? If so, I should be able to use it on my WA22 since it can handle the ECC32 right?
That's what I thought since some of my amps can handle an ECC32 at 0.9V then the 6H12C should be safe.
I was contemplating for a couple of weeks and when Glenn told me it's safe to use in his OTL try and see if you like it, I did.
Nice, Stavros! Other than the identical 0.9a heater current, how similar are they to the ECC32 electrically ?
Perhaps someone has more info on this tube? I have not seen a such a uniform round mica on a 6F8G before (usually they have tiny protrusions ala Tung Sol). click to enlarge
Thanks Rob,
It looks great it's a small tube and feels very robust like the 1578.
It has a plate voltage of 180V here are the specs
6H12C.pdf 205k .pdf file
Hi Xcalibur
I got these Sylvania GT's last week.
The ones on either side are the ones you like, I believe.
What is the centre one? It has a full getter flashing but also a taller base. Could it be the same as the Syl 6SN7W? Alternatively, could it be the same as the tube I posted about last year (pictured below), which could possibly be the true Chrome Dome?
Thanks
My RCAs have the same type mica, maybe this is RCA made.
Does it have a makers code?
Ok so these came today:
Straight into my 336SE and there is a slight background hum on the left channel. Should give it a few hours or so of burn-in to give the tubes enough time to soothe itself and see if the hum disappears?
Or you can try tapping the top of the tube with something soft. Like the eraser of an pencil. I do that when I hear noise/hum from a tube, usually it works.
I must say that it took quite a while to find out what that could be. 
Well, without knowing the tube code it's kinda tough. Wehrmacht tubes were the WW2 German Military tubes. Tube numbering scheme I believe was totally unique to them during the period.
So...what is it?
I think we have a twister here. I'll keep quiet for now in case there are others who like the challenge.