Well there you go, the 254m has a loctal base. The ITT tubes are later production but that base was used with old tubes. Must have been a last run of replacements for old equipment. I have 2 STC/ITT tubes, the aforementioned 5b/254m and the 5a/152m. Both are wonderful. The 5b/254m look like miniature tubes when compared to 807.The 5b/254a is essentially a classic 807 in a small straight glass with a smaller top cap. Again I want to hear the difference between 254a and 254m if there's any.
Who said that? Langrex.
5B/254A Valve Tube = 5B/254M with a UX5 Base
How is this not beautiful. Those glasses are thick, much thicker than most tubes. One of the most robust beam tetrode I've held in my hands.
I've not heard of KT8C until now. Apparently the British Services abandoned it in favour of the American 807.
I thought that was a typo error.
KT8C is cheap but I'm not going to try another power tube. I've 2 amps powered on now. One has EL39 and the other KT88. Life is already too beautiful. All I have to do is plug my headphone into anyone of them.
You need another adapter ! I've so many adapters already.
Right there with you. I have so, so many tubes with so many good sounding combos. For my birthday I finally got the n78 (and adapters sigh) that I had been intrigued by for so long. It was an indulgence though.
The GU50 is really the only reason to get 12v output tubes IMO. I can’t think of any other 12v output tubes that are much cheaper or different to 6v tubes. Once upon a time you could get TT22 but those are gone for the most part. And if you do find some they are hardly cheap tubes. Some, like the 12aq5 and 12v6 are cheaper than the 6v equivalent but have far fewer options. Pity more of the European companies didn’t make 12v output tubes. GU50 is amazing but I think it needs a dedicated design to really take advantage of it. On the plus side, I think that running them at only 350v in triode means they’ll last forever
