6dj8 phono amp

[voycieck]

I'm building phono amp. I want to use 6922 tubes in second stage and the tubes I have are made in Japan by National Elecric. On box says:
157-0125-00
date is 7/87
Does anybody know if those are a 6922 type tubes and if not what they are?

[Globulator]

Lack of visual input error 4562.

[voycieck]

I don't know what You mean by visual input error 4562. I'm kind of new here. I need to add that tube has shield between sections.

[mashaffer]

I think he means post a picture of the tubes in question. As number 5 would say. "More input".

[voycieck]

Originally Posted by mashaffer

I think he means post a picture of the tubes in question. As number 5 would say. "More input".

Thank You for replay. I have picture but I don't know how to post it here. It appears that my computer doesn't want to cooperate. I try it again.

[Frank Berry]

What is the pinout of the tube?
If it is the same as the 6922, it may be a 6DJ8 or a 6922.
The 6DJ8 tends to have more noise than the 6922.
It may work okay in the second stage.

[voycieck]

As far as I can tell by looking at the tube the pin #1 & 6 are anodes and #9 is internal shield. So it may be 6922 or 6DJ8. Part number 157-0125-00 may be Tektronix part number, I don't know for sure, and they used 6922 and 6DJ8 tubes in their scopes. If my tubes are industrial versions, I wander how good are they for audio applications.

[the_manta]

According to that Tubes inconnus,,,besoin d'aide - Général Haute-Fidélité and knowledge of french language from school (It was living hell ), these tubes really seem to be authentic 6DJ8/6922/ECC88. Your picture supports that opinion, too. They were rebranded by National (=Richardson) for a very special purpose. Where did you got them ?

[tricomp]

Something very strange is going on here.

The 5960... number below the bar code is a National Stock Number
Starting with 5960 it indicates an electronic tube (Surprise! )
The number is normally viewed in this format: 5960-00-131-1218
Checking it out it certainly references to Tektronix and to one of their partno's: 157-0125-00
Just one glitch: That appears to be a Cathode Ray Tube

FYI the NSN x-ref's to an older number: 5960-00-245-6551 but that's not likely to do you much good.

rgds,

/tri-comp

[voycieck]

Originally Posted by the_manta

According to that Tubes inconnus,,,besoin d'aide - Général Haute-Fidélité and knowledge of french language from school (It was living hell ), these tubes really seem to be authentic 6DJ8/6922/ECC88. Your picture supports that opinion, too. They were rebranded by National (=Richardson) for a very special purpose. Where did you got them ?

Thank You for quick reply. Now I'm going ahead with my project. As to the tubes, I got them from Richardson Elect. LTD some years ago for the power amp, the same amp. my cat is warming up in. They were cheap so I got ten of them. I couldn't get any datasheets for them so I end up using 12EU7's. Now I want to bring them back to life again. Thank You again.