Are they true beam tetrodes like old American made 6CA7s or are they EL34s labeled with the alternative designation of "6CA7?"
Can anyone comment on what they sound like?
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sailor wrote:To know for sure about any brand of 6CA7 you must check the data sheet for that exact tube and brand. The EH is a tetrode the Sevtlana EL34/6CA7 is a pentode. Unfortunately without the data sheets on the 2 that you are looking at it is impossible to know. However if they list the 2 together I would suspect pentode. As in EL34/6CA7 as listed on the Psvane 6CA7/EL34-TII. The EH is modeled after the Phillips Big Bottle 6CA7 tetrode and sounds nothing like a EL34. The JJ 6CA7 is also a pentode.
Yes i know. That sheet is in error ( i guess it's a language issue). If you look at the sheetsailor wrote:Check the above link to the JJ 6CA7 data sheet. It is listed and pictured as a pentode.
I will dissect an JJ-6CA7 in due time and report back(if anyone is interested)sailor wrote:In the old days the El34 was a 6CA7, IE: European versus American designation. My Mullards say they are both. So anyone can produce a pentode and justifiable call it a 6Ca7. The only thing I can see that would make it a pintode is if pin 1 is connected to grid 3 as pictured [JJ].
All I know is I can't find a data sheet that shows an internal diagram or pin out for either the EH or the Phillips big bottle. As far as JJ goes, I am glad they are in the tube business but you are right about the fact you can't always trust what the say or claim. After all they claim they produce a 12AX7 that is a copy of the venerable Telefunken but there designs have nothing in common with each other. JJ short plate Big T. long plate. EI on the other had did make exact copies just not as good a quality control because they bought Telefunkens tube making equipment.
All I know for sure is the EH big bottle are great sounding tubes and that is compared to NOS EL34 Mullards. However if midrange detail is your thing with rolled off bass and highs then the EL34 the way to go. I have never owned or heard the big bottle JJ so I can't comment.