Tube Identification

fauxpas · 26th December 2007, 11:04 AM

This ebay listing of a Yaqin MC5881A amp has the 5881 (6L6) power tubes and 12AX7 / 12AU7 preamp tubes and the other tubes look to me like rectifying tubes, but are listed as 6N6? I looked up 6N6 tubes and they look nothing like those. Can someone tell me what they are?

Original Burnedfingers · 26th December 2007, 11:23 AM

Quote:

This ebay listing of a Yaqin MC5881A amp has the 5881 (6L6) power tubes and 12AX7 / 12AU7 preamp tubes and the other tubes look to me like rectifying tubes, but are listed as 6N6? I looked up 6N6 tubes and they look nothing like those. Can someone tell me what they are?

Looks to me like 5881/6l6's, 12AX7, 12AU7, and the other two are display tubes? (showing output?)

Colt45 · 26th December 2007, 12:06 PM

I see

4x 6l6
4x 6N1P
2x EMxx (display..)

fauxpas · 26th December 2007, 12:22 PM

OK, 2 of 2 saying display tubes. I'm new to this concept. Are they there just to look pretty? Indicate volume or something?

Ty_Bower · 26th December 2007, 12:34 PM

Have you ever seen the "Magic Eye" indicator? I saw a couple used to indicate signal strength for FM tuners, or record level on reel to reel tape decks.

There is a strip of phosphor or something inside the tube. It gives off an eerie greenish glow. The length of the glowing part of the strip can vary depending on some value - perhaps bias, or input level, or something.

Have a look at the first photo on this page:
http://hhscott.com/cc/magic_eyes.htm

Original Burnedfingers · 26th December 2007, 12:35 PM

Quote:

Indicate volume or something?

Yes

fauxpas · 26th December 2007, 12:50 PM

Sweet. Cheers and thanks.

jlsem · 26th December 2007, 01:14 PM

The eye tubes may also be used to indicate balance in the push-pull output stage.

John

26th December 2007, 11:04 AM	#1
fauxpas diyAudio Member Join Date: Nov 2007	Tube Identification This ebay listing of a Yaqin MC5881A amp has the 5881 (6L6) power tubes and 12AX7 / 12AU7 preamp tubes and the other tubes look to me like rectifying tubes, but are listed as 6N6? I looked up 6N6 tubes and they look nothing like those. Can someone tell me what they are?

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26th December 2007, 12:06 PM	#3
Colt45 diyAudio Member Join Date: Feb 2002 Location: Canada	I see 4x 6l6 4x 6N1P 2x EMxx (display..)

26th December 2007, 12:22 PM	#4
fauxpas diyAudio Member Join Date: Nov 2007	OK, 2 of 2 saying display tubes. I'm new to this concept. Are they there just to look pretty? Indicate volume or something?

26th December 2007, 12:34 PM	#5
Ty_Bower diyAudio Member Join Date: Mar 2007 Location: Newark, DE	Have you ever seen the "Magic Eye" indicator? I saw a couple used to indicate signal strength for FM tuners, or record level on reel to reel tape decks. There is a strip of phosphor or something inside the tube. It gives off an eerie greenish glow. The length of the glowing part of the strip can vary depending on some value - perhaps bias, or input level, or something. Have a look at the first photo on this page: http://hhscott.com/cc/magic_eyes.htm

26th December 2007, 12:50 PM	#7
fauxpas diyAudio Member Join Date: Nov 2007	Sweet. Cheers and thanks.

26th December 2007, 01:14 PM	#8
jlsem diyAudio Member Join Date: Jun 2003 Location: Dallas,TX	The eye tubes may also be used to indicate balance in the push-pull output stage. John

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