6E2 vacuum tube compatibility - 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 15th January 2012, 12:45 PM   #1
Penegal is offline Penegal  France
diyAudio Member
 
Join Date: Jan 2012
Location: Vosges
Default 6E2 vacuum tube compatibility

Hello, everybody.

I am considering buying a vacuum tube amplifier, which includes a 6E2 (EM87) magic eye for retro look, and I wonder if I could safely exchange this tube with the pin-compatible EM85? By safely, I mean without any modification of the amplifier device.

For memory, here are these tubes data sheets :
Thank you in advance.

Regards.
  Reply With Quote
Old 15th January 2012, 02:12 PM   #2
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
You might need to change the resistor on pin 9, the triode anode. EM85 says 470k, EM87 is 100k. Failing to do this probably won't do any harm, but the indication may be wrong (e.g. cramped at one end of the range).
  Reply With Quote
Old 15th January 2012, 02:18 PM   #3
Jebem is offline Jebem  Portugal
diyAudio Member
 
Jebem's Avatar
 
Join Date: Dec 2011
Location: Lisbon
They have the same pin out and similar electrical working voltages, so it should be possible to use either one without circuit modifications.
__________________
If You need something done properly, do it yourself (and ask help from DIYaudio... )
One of my SE 211 tube amps: http://sites.google.com/site/sunajeb...ificador-211se
  Reply With Quote
Old 15th January 2012, 04:31 PM   #4
Penegal is offline Penegal  France
diyAudio Member
 
Join Date: Jan 2012
Location: Vosges
If I understand, changing the 6E2 with the EM85 will lead to an decreased sensitivity of the magic eye?

In this case, can I put on of these tubes instead of the furnished 6E2 :
They seems to be pin-compatible, as they have both noval pin, but I have to admit that my electronics learning are far in my college years.

By the way, if somebody knows a magic eye tube which has a shadow sector pattern and is pin-compatible with 6E2, I'll take it!
  Reply With Quote
Old 15th January 2012, 05:14 PM   #5
diyAudio Member
 
the_manta's Avatar
 
Join Date: Nov 2006
Location: Munich, Bavaria
EM85 is very rare and was used in some Schaub-Lorenz and SABA radios. It is really a better idea to hand them over to some collectors or something.

Why don't you use russian magic eyes ? There are tons of them out there. 6Е1П has a nice shadow sector pattern and is available from ebay. Here is a nice page where you can see nearly every magic eye ever produced.
__________________
Терпенье и труд все перетрут
  Reply With Quote
Old 15th January 2012, 06:15 PM   #6
Penegal is offline Penegal  France
diyAudio Member
 
Join Date: Jan 2012
Location: Vosges
6Е1П (EM80)? Да, товарищ; nevertheless, do its characteristics fits to replace an EM87 tube without any modification of the host circuit? No sensitivity problem to expect?
  Reply With Quote
Old 16th January 2012, 08:03 AM   #7
diyAudio Member
 
Blaireau's Avatar
 
Join Date: May 2011
Location: Dijon
To replace an EM87, you can directly use an EM84 or a 6Е2П without any problem. I've already tried that several times. The anode résistor was 470K in each case. The patterns are quite similar, although not always perfectly centered, by this little defect is inherent to the eye's machanical construction. In a stereo amp, the main difficulty will be to find two eyes whith exactly the same pattern. EM84-6E3P
__________________
http://constructions.f6fkn.com
  Reply With Quote
Old 16th January 2012, 04:36 PM   #8
Penegal is offline Penegal  France
diyAudio Member
 
Join Date: Jan 2012
Location: Vosges
Concerning the EM84, I was under the impression that it has a similar pattern than EM87, and yet I would like another pattern than the light band pattern of EM87, something similar to EM80 (preferably), EM81 or EM85; is the 6Е2П tube matching with what I'm looking for?
  Reply With Quote
Old 16th January 2012, 05:43 PM   #9
diyAudio Member
 
Blaireau's Avatar
 
Join Date: May 2011
Location: Dijon
"is the 6Е2П tube matching with what I'm looking for? " Sorry, I made a confusion between 6e2p and 6e3p. 6e3p has a pattern which is similar to EM87 and EM84. (variable length luminous strip) 6e2p is really different, more looking like a magic eye.
__________________
http://constructions.f6fkn.com
  Reply With Quote
Old 18th January 2012, 06:27 AM   #10
Penegal is offline Penegal  France
diyAudio Member
 
Join Date: Jan 2012
Location: Vosges
Er... You lost me here : are some of these tubes matching with what I'm searching?
  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
Vacuum tubes, vacuum capacitors and vacuum relays GREENSTONE USA Vendor's Bazaar 0 19th August 2011 03:38 PM
Adjusting the sensitivity on a 6e2 magic eye tube bbbing Tubes / Valves 4 21st May 2010 07:28 PM
Vacuum Tube Voltmeters Captn Dave Tubes / Valves 14 29th January 2010 08:01 PM
The Vacuum Tube Truth Serratoga Tubes / Valves 31 29th November 2007 09:25 PM
Vacuum Tube Pre O.C.L. gianmaria Tubes / Valves 13 16th February 2006 06:32 PM


New To Site? Need Help?

All times are GMT. The time now is 10:49 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