6E2 vacuum tube compatibility

Penegal · 15th January 2012, 12:45 PM

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 :

6E2
EM85

Thank you in advance.

Regards.

DF96 · 15th January 2012, 02:12 PM

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).

Jebem · 15th January 2012, 02:18 PM

They have the same pin out and similar electrical working voltages, so it should be possible to use either one without circuit modifications.

Penegal · 15th January 2012, 04:31 PM

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 :

EMM801
EM81

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!

the_manta · 15th January 2012, 05:14 PM

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.

Penegal · 15th January 2012, 06:15 PM

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?

Blaireau · 16th January 2012, 08:03 AM

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

Penegal · 16th January 2012, 04:36 PM

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?

Blaireau · 16th January 2012, 05:43 PM

"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.

Penegal · 18th January 2012, 06:27 AM

Er... You lost me here : are some of these tubes matching with what I'm searching?

15th January 2012, 12:45 PM	#1
Penegal diyAudio Member Join Date: Jan 2012 Location: Vosges	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 : 6E2 EM85 Thank you in advance. Regards.

15th January 2012, 02:18 PM	#3
Jebem diyAudio Member 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

15th January 2012, 04:31 PM	#4
Penegal 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 : EMM801 EM81 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!

15th January 2012, 05:14 PM	#5
the_manta diyAudio Member 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

15th January 2012, 06:15 PM	#6
Penegal 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?


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15th January 2012, 02:12 PM	#2
DF96 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).

16th January 2012, 08:03 AM	#7
Blaireau diyAudio Member 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

16th January 2012, 04:36 PM	#8
Penegal 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?

16th January 2012, 05:43 PM	#9
Blaireau diyAudio Member 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

18th January 2012, 06:27 AM	#10
Penegal diyAudio Member Join Date: Jan 2012 Location: Vosges	Er... You lost me here : are some of these tubes matching with what I'm searching?

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