The History of the EL-34 and other Pentodes and Beam Tetrodes. - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 30th May 2012, 06:53 AM   #11
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Also there were PenA4 (pentode) and KT41 (Kinkless Tetrode)
__________________
The Devil is not so terrible as his math model is!
  Reply With Quote
Old 30th May 2012, 06:57 AM   #12
Yvesm is offline Yvesm  France
diyAudio Member
 
Yvesm's Avatar
 
Join Date: Jul 2004
Location: Ardeche
Quote:
Originally Posted by dirkwright View Post
The 6L6 was the first beam power tube. Developed in the 1930's. I used to have the article that described the development of that tube. The article doesn't appear to be online.
Do you mean this one ?

http://www.dissident-audio.com/Outsi...TechPapers.pdf

Happy reading !

Yves.
  Reply With Quote
Old 30th May 2012, 05:38 PM   #13
TheGimp is offline TheGimp  United States
diyAudio Member
 
TheGimp's Avatar
 
Join Date: Aug 2009
Location: Johnson City, TN
There is also this from Ken-Rad:

http://www.clarisonus.com/Archives/T...0Amplifier.pdf
  Reply With Quote
Old 30th May 2012, 10:27 PM   #14
diyAudio Member
 
Join Date: Oct 2011
Location: Tauberbischofsheim, Germany
Quote:
Originally Posted by Wavebourn View Post
6L6 was introduced in July 1936...
The European AL5, undoubtedly a beam power valve, also saw the market's light in 1936. Does anyone know the month of it's introduction?
  Reply With Quote
Old 30th May 2012, 10:39 PM   #15
diyAudio Member
 
Join Date: Apr 2007
April, according to AL 5, Tube AL5; Röhre AL 5 ID585, Vacuum Pentode
__________________
I'm not allowed to do magic, union rules...
  Reply With Quote
Old 30th May 2012, 10:43 PM   #16
diyAudio Member
 
Join Date: Oct 2011
Location: Tauberbischofsheim, Germany
So it's the AL5, noit the 6L6, to be the first beam power tube!

Best regards!
  Reply With Quote
Old 30th May 2012, 10:44 PM   #17
diyAudio Member
 
Join Date: Apr 2007
Reading furter on AL 5, Tube AL5; Röhre AL 5 ID585, Vacuum Pentode it stated that the AL5 was first introduced as a pentode and later, in late -37 issued by telefunken in a beam tetrode version.

/Olof
__________________
I'm not allowed to do magic, union rules...
  Reply With Quote
Old 31st May 2012, 12:00 AM   #18
diyAudio Member
 
Join Date: Aug 2008
It may well be the AL4, from April '36.

AL 4, Tube AL4; Röhre AL 4 ID558, Vacuum Pentode

This may be significant, cause they were used in the special amplifier developed for Disney's "Fantasia" by RCA.

http://www.oswaldsmillaudio.com/imag...m/DSC_0831.jpg

Top rack, the black ones next to the 300B's. There surely were reasons they were chosen in this design.

Last edited by costis_n; 31st May 2012 at 12:04 AM.
  Reply With Quote
Old 31st May 2012, 01:02 AM   #19
diyAudio Member
 
Join Date: Mar 2012
Quote:
Originally Posted by costis_n View Post
I need that system.
  Reply With Quote
Old 31st May 2012, 02:18 AM   #20
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
I could be mistaken, but I suspect the OMA amplifier referenced above is not an RCA creation at all, but something OMA cooked up to drive the big power amplifiers. Might want to dig into that a bit further, just sayin'.

Given the time frame and the fact that it was RCA it seems very unlikely that they would have used a foreign tube, or even one made by a "domestic competitor" other than GE. AFAIK RCA never used the 300B in one of their cinema designs. Even tubes made in the UK were not common here in those days, let alone one manufactured in Germany.
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Output (beam) pentodes / tetrodes suitable for screen grid drive ilimzn Tubes / Valves 19 15th June 2013 07:23 AM
EL-34 to 6P3S-E Laila2 Tubes / Valves 21 1st November 2010 10:13 PM
Beam pentodes and suppressor-grid pentodes of same type jon_010101 Tubes / Valves 3 3rd May 2009 12:18 AM
Single Ended EL-34? jaymanaa Tubes / Valves 11 28th March 2006 11:32 PM
el-34 suggestion mezon Tubes / Valves 7 10th April 2003 10:28 PM


New To Site? Need Help?

All times are GMT. The time now is 05:19 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2