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Russian pentodes 6J2P-EB and 6J9P

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kees52

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Joined 2009
Hi here

I have this tubes from ebay, the 6J2P-EB is small little tube, I need a new socket, someone now what type?

The 6J9P is microfonic, if I tap it pinggggg in the speaker, I have it as triode strapped in a hybride amp as voltage amp, I have discover that the tube sounds very nice, special with a plate resistor, a ccs or other mosfet use is not so good sounding, a lot of hissssss in the voices of singers.

The small little 6J2P-EB is a lot better made, no zingg.

I ask myself how it sounds as I use not triode but penthode strapped, is there somewhere a calculation program for penthodes?

thanks
 
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the_manta

the_manta

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Joined 2006
6Ж2П has the standard widely used miniature 7-pin (Pico-7, B7G) socket. Nothing uncommon.
But, this is a remote cutoff valve. Probably it belongs to some AGC circuit for RF. Expect some serious distortion when it is operated in the "knee" of the curve.

And 6Ж9П = E180F

I don't know what you mean by calculation programm. When you got the curves and parameters of your tube you can start playing around and designing your circuit.
 

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K

kees52

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Joined 2009
I have ordered here.

6J2P-EV Russian Tubes Pentod Equ. 6AS6, 5725 Lot of 40 | eBay

is for voltage amplification, but if I do them CCS loaded touching the knee is easely prevented if i have right, with high idle current.

I am not so experienced with tube data en tubes himselfs, I have design a hybrid who is playing some years now and I experienting with it, so try different tubes.

thanks for your info.
 
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piano3

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Joined 2010
I have used 6j9p-e many times; yes, if you tap it you will get a silvery ring but why do you need to tap it? I have not had any problems in normal use including 2nd stage of a MM phono. A chassis which does not ring should help. It is an excellent tube and still cheap and plentiful.
 
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kees52

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Joined 2009
piano3 said:
I have used 6j9p-e many times; yes, if you tap it you will get a silvery ring but why do you need to tap it? I have not had any problems in normal use including 2nd stage of a MM phono. A chassis which does not ring should help. It is an excellent tube and still cheap and plentiful.
Click to expand...

I don,t need to tap it, but I did presume that if it do ringing then she are bad, as I now here from you that is not the case.

I have them in my amp, it sounds very good in triode mode, I don,t now yet how it sounds as a penthode, what I do now, a plate resistor works best for them, a ccs or gyrator on plate let them give the ssss sound in voices.

I have ordered the 6j51p also as test, and the 6H8C for cascode, but these are quite expensive in some cases, the 6sn7 is be produced again and cheaper then, so I stick to that.
 
the_manta

the_manta

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Joined 2006
Blaireau said:
http://frank.pocnet.net/sheets/112/6/6Z2PEV.pdf 6J2P or 6J2P-EV have a transconductance of 4.15 ma/V. But, they are not remote cutoff tubes.
Click to expand...

Indeed ! You are right, I misinterpreted that. It was used in dual control amplifiers
But the curves look strange just like the Early-effect in BJTs. Would love to see blueprints of its internal structure

Furthermore the lovely made CSF datasheet (http://frank.pocnet.net/sheets/181/5/5725.pdf) of the wester equivalent type says it used as variable gain amplifier (amplificateur à gain réglable)

But with enough current you should be well in the linear region.
 
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kees52

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Joined 2009
Well I will try them in the hybrid amp. post the sound (youtube) here if ready. the best I have heard was still the 6H8C self bias cascode, very full and free, only if the next stage has very high impedance, to let 6H8C swing free.. Now I have put in (just did) the EF184 this sounds also very good (triode mode). try it in penthode mode, plate resitor is 15 kohm, current 10 mA. 6J2 grid 3 tyed on cathode, like al the others because this was the control grid, if I am right, we don,t use it on audio.
 
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