6E5 as a VU meter for guitar amp?

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6E5 as a VU meter for guitar amp?

Postby nyazzip » Fri Oct 12, 2012 7:11 pm

i acquired one of these eye tubes awhile back. would it be complicated to hook it up so the "eye" moves in concert with the audio signal...?
i haven't looked into it at all yet. just for show, not practical function......
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Postby Geek » Fri Oct 12, 2012 9:19 pm

Heh, your biggest problem will be finding a socket for that sucker ;)

In the RCA tube manual, there's a section on using these.
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Postby nyazzip » Fri Oct 12, 2012 9:35 pm

it came with the socket! anyway, on something like that i wouldn't mind just hard-soldering it in or whatever
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Postby DeathRex » Sat Oct 13, 2012 10:46 am

I got several chinese 6e2/EM87s for cheap on ebay, something like $4 each with a socket. They were selling them for line level indicators. On my navy transmitter amp I use a 6AF6G since it has 2 shadows, it will do stereo. I used a 6F8G as a buffer, and a 6C8G as voltage amplifier, since the 6AF6G doesn't have one built in, with a diode inbetween. You'll also need a capacitor to adjust the speed of the indicator.
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Postby Greg Smith » Wed Nov 07, 2012 10:45 am

Adding a 6E5 to any audio project is worthwhile, if only to afford you the opportunity to utter the words "electron ray tube" about 1000 times more often than the average mortal.

"What's that green glowy thing?"
"It's an electron ray tube."
"Cool!"

I added one to a hi-fi preamp, using the basic circuit in Figure 2 on this page:
http://koti.mbnet.fi/siliconf/JukkaTolo ... akmtr.html

The circuit is for an EM87, but works well with a 6E5. You'll need to connect it to a point in the circuit that has enough drive voltage to close the "shadow" on the 6E5....a few volts P-P...you'll probably have to put a trimmer in front of the circuit to adjust the range.

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