Pure Tetrode for Audio ?

[santitrucco]

Is a pure tetrode (not Beam Tetrode) optimal for audio?

In tetrode or UL Mode.
I am talking about the Western Electric 350A in particular.

It is a pure tetrode.

 

[rayma]

Here's a clue.
https://www.electronics-notes.com/images/valve-tube-beam-tetrode-pentode-characteristic-curves.svg

 

[santitrucco]

Here's a clue.
https://www.electronics-notes.com/images/valve-tube-beam-tetrode-pentode-characteristic-curves.svg

It seems that at lower voltage than suggested the tetrodes would have problems?

 

[32860]

The 350A is a beam tetrode. See this page from a Western Electric databook:

 

[johan]

As I understood it, the original tetrode (as per the original design) is rare. All of the common ones are beam power tetrodes or some other less common type (kinkless tetrode, radial beam tetrode). In this forum someone mentions WE448 and QQV02-6 that supposedly are pure tetrodes.

 

[santitrucco]

Thanks boys, i had only this info.

And dont have voltage info for screen grid and say only tetrode.

Information also from Western Electric

 

[32860]

Take a look at this thread: https://www.diyaudio.com/forums/tubes-valves/305158-6l6gc-ul-data-sheet.html#post5018822

 

[Bigun]

6E5P

I didn’t like the sound in pure Tetrode when used as a spud, so I wired up a bit of plate feedback. But on subsequent listening I believe I could adjust to the Tetrode sound depending on speaker.