Tubes Asylum

JJ 12ax7

76.90.100.230

Tre'

P

I was given some of these 12ax7s and they look like they are designed like a Guided grid valve. You can see the "Active Anode Area" in my picture. They look like they are built like a 6gk5.
I wonder how they get a tube, that is designed so differently (than the standard 12ax7), to act like a 12ax7?

Most of the plate is screened from the grid so tubes made this way have almost no interelectrode capacitance (and therefore almost no Miller capacitance).
Tre'

Have Fun and Enjoy the Music
"Still Working the Problem"

Edits: 04/28/24 04/28/24

Follow Ups:

RE: JJ 12ax7 - dogscanskate 05:44:07 04/29/24 (12)
Are they marked E83CC? If so the design is based off the Tele Ecc803s and Tesla E83cc. I have some Tesla and they fit the diagram you've shown, if this can help.
- Thanks, I see that now. - Tre' 09:11:41 04/29/24 (11)
  There are a lot of tubes designed that way. I just didn't know 12ax7s were.
  
  Tre'
  
  Have Fun and Enjoy the Music
  "Still Working the Problem"
  - RE: Thanks, I see that now. - Mendel 16:10:08 05/01/24 (10)
    The frame grid JJe83cc is a very good sounding tube, by far the best new production 12ax7 tube I have tried. They claim it is based on the Tesla e83cc frame grid tube. I agree it is very unusual looking for a 12ax7, looks more like a 6dj8.
    - RE: Thanks, I see that now. - Tre' 19:40:40 05/01/24 (9)
      This is weird. The JJ ECC 803s is not built like a Telefunken ECC 803s but the JJ ECC 83s is.
      
      Tre'
      Have Fun and Enjoy the Music
      "Still Working the Problem"
      - JJ makes 7 or 8 different 12ax7 types...- - Mendel 19:20:00 05/02/24 (7)
        
        In Reply to: RE: Thanks, I see that now. posted by Tre' on May 01, 2024 at 19:40:40
        
        I have not tried the others, but the one I am talking about, with the frame grid design is the JJ E83CC. The first modern small signal tube that I have heard that is competitive with vintage tubes.
        
        Second that_nT - Cleantimestream 13:24:53 06/01/24 (0)
        
        In Reply to: RE: JJ makes 7 or 8 different 12ax7 types...- posted by Mendel on May 02, 2024 at 19:20:00
        
        !
        The Mind has No Firewall~ U.S. Army War College.
        
        I wonder how the JJ E83CC compares with the JJ ECC 83s which is - Tre' 10:23:29 05/03/24 (0)
        
        In Reply to: RE: JJ makes 7 or 8 different 12ax7 types...- posted by Mendel on May 02, 2024 at 19:20:00
        
        also a frame grid design.
        
        I don't know if all frame grid tubes are guided grid tubes. (see link below) I know the 6gk5 is.
        
        Tre'
        Have Fun and Enjoy the Music
        "Still Working the Problem"
        https://www.thevalvepage.com/valvetek/guidgrid/guidgrid.htm (Open in New Window)
        
        "Harmonically Rich" - Triode_Kingdom 08:18:23 05/03/24 (3)
        
        In Reply to: RE: JJ makes 7 or 8 different 12ax7 types...- posted by Mendel on May 02, 2024 at 19:20:00
        
        When JJ describes a tube as "harmonically rich," does that mean it's designed to produce high distortion (like the ECC83S description below)?
        Also, is your recommendation for the E83CC frame grid version the correct number? Doesn't seem to be on JJ's Website.
        
        Edits: 05/03/24 05/03/24 05/03/24
        
        RE: "Harmonically Rich" - Tre' 11:09:44 05/03/24 (2)
        
        In Reply to: RE: "Harmonically Rich" posted by Triode_Kingdom on May 03, 2024 at 08:18:23
        
        Here's a review of the JJ E83CC
        
        Tre'
        Have Fun and Enjoy the Music
        "Still Working the Problem"
        https://blog.thetubestore.com/review-jj-e83cc-12ax7-tube/ (Open in New Window)
        
        RE: "Harmonically Rich" - Triode_Kingdom 14:11:27 05/03/24 (1)
        
        In Reply to: RE: "Harmonically Rich" posted by Tre' on May 03, 2024 at 11:09:44
        
        Thanks, I do see quite a few sites with reviews and conversations on this tube. What I said before about not finding it on JJ's site - it appears this company has more than one "home" URL, and the links to preamplifier tubes don't go to the same place. One is a three-page listing of JJ small signal tubes that doesn't have this. The other URL, which is a *.EU site, shows the tube and the curves. Weird.
        
        JJ Website Missing the E83CC (Open in New Window)
        
        I agree, that is weird. nt - Tre' 14:18:06 05/03/24 (0)
        
        In Reply to: RE: "Harmonically Rich" posted by Triode_Kingdom on May 03, 2024 at 14:11:27
        
        .
        Have Fun and Enjoy the Music
        "Still Working the Problem"
        
        Amen, brother! +1 - Sondek 06:45:52 05/03/24 (0)
        
        In Reply to: RE: JJ makes 7 or 8 different 12ax7 types...- posted by Mendel on May 02, 2024 at 19:20:00
        
        A great sounding tube.
        
        Completely agree.
      - RE: Thanks, I see that now. - Nunki 02:14:14 05/02/24 (0)
        
        In Reply to: RE: Thanks, I see that now. posted by Tre' on May 01, 2024 at 19:40:40
        
        compared with vintage ECC83 types the upper midrange of JJ�s sounds nervously to my ears. but fine when other people like them...

Post a Followup:

FAQ

Post a Message!

Forgot Password?

Moniker (Username):
Password (Optional):
	Remember my Moniker & Password (What's this?) Eat Me
E-Mail (Optional):
Subject:

Message:	(Posts are subject to Content Rules)

Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:	Automagically notify you when someone responds.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.

This post is made possible by the generous support of people like you and our sponsors:

Schiit Audio