Quote:
Originally Posted by Tubejunke
I didn't even think about subs. If the 6CA7 is an older sub for an EL-34, then I could just use those settings for a test. I know that amp tubes like the EL-34 aren't new news by any stretch. However, the part # doesn't go back as far as a lot of, probably most of, the vintage scrolls provide data for. Out of the 4 or 5 testers that I have, I am sure that more than one will do the 6CA7.
Heck, although I do play guitar and have one tube amp, I don't expect to be worried about any EL-34s soon if ever. My Epiphone is circa late 50s. No octals; just miniatures.  |
European tube designations start with letters, American ones start with numbers. E is a 6 volt filament L is a power pentode, and 34 is the sequential number. 6 is a 6 volt filament CA is the sequential desinator, and 7 means 7 elements inside the tube, i.e. a pentode. The reason it is 7 for a 6CA7 is the supressor grid is brought out as a separate element, unlike the 6L6 where the beam forming plates are internally connected to the cathode.
All that said, when the EL34 was introduced in North America, in the 1950s, it was called the 6CA7, under the American naming convention. It's exactly the same tube, just under an American title. Other examples exist, for example
EL84 = 6BQ5
ECC83 = 12AX7
GZ34 = 5AR4
And on and on and on All are european tubes with American designations, probably to make them easier to sell and categorize in existing US inventory systems at the time.