Current production 12AX7 internals

[wpaulvogel]

I'm wondering if it's just me or if the current 12AX7 plate structure is smaller. Most of the tubes for yesterday had 17mm or 19mm plates. Is there a logical reason for shortening the plates other than cost savings in manufacture? Can it make them less microphonic? Is this why the older tubes have those magic harmonics and richness and warmth. Opinions please. I have a small collection of good old tubes and I use JJ ECC83s in a lot of my amps and think they sound O.K. The old Amperex and Tungsram do have more though.

[xtian]

JJ, as an example, offers short plate <https://www.tubesandmore.com/products/v ... lectronics> and long plate <https://www.tubesandmore.com/products/v ... long-plate> versions.

[wpaulvogel]

I made a mistake on the plate dimensions too. I meant 14 mm and 17 mm. The short plate JJ seems a bit smaller. Same with the Chinese and Russian tubes. Maybe I’m over analyzing this.

[Roe]

new tubes differ from the old specs. often the new 83s have less voltage gain but deliever more current than a vintage ecc83. as such the new ones may work in the phase inverter

[Stevem]

There's no ifs , and's or but's about it for me, original type longer plate structure and internal structure tubes sound better ( way fatter sound stage!) and last far longer!!

To me you have to just about run a newer type short structure tube wired with its two sections in parallel to match the tone and harmonics you get out of the big structure tubes!

The short plate newer type tubes unfortunately are what's needed for combo amps of over 15 to 20 watts of solid RMS power and good bass responce for no microphonics to plegg you.

[wpaulvogel]

Steven, that’s where I was going with the thread. The actual purpose for shrinking them. I was thinking microphonics also. I don’t play combos and rarely play through anything but my Marshall 1960AV. I have a few 1 12 cabinets but prefer the 4 12. The old tubes are the cake. There’s a lot of people that are scared to purchase/try them out. I’m confused because they last a long time, compared to cp.

[wpaulvogel]

Stevem, that’s where I was going with the thread. The actual purpose for shrinking them. I was thinking microphonics also. I don’t play combos and rarely play through anything but my Marshall 1960AV. I have a few 1 12 cabinets but prefer the 4 12. The old tubes are the cake. There’s a lot of people that are scared to purchase/try them out. I’m confused because they last a long time, compared to cp.