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    Building, troubleshooting and testing of these amplifiers should only be
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    the safety precautions around high voltages.

Simple Magic Eye Circuit Wanted

If using it as a level indicator to detect a signal that contains no DC. You will have to rectify the signal to produce a negative voltage. Then use a cap to filter it to -DC. So a diode and a cap or a bridge rectifier and a cap. And you will probably want to put a bleeder across the cap so it doesn't just hold the lowest value for ever.

If detecting a signal that also contains a positive DC. You must first use a coupling cap to block the positive DC before doing the process mentioned above.


If your using it to detect bias I'll have to see the circuit your adapting it to.
 
The attached circuit is an excerpt from one of my projects. EM71 has an interesting non-linear, degressive characteristic somewhat suitable for output level (power) "metering", showing movements at low levels already, while not running into full reading too fast.

Tom

P.S.: The C3 value as shown is vast overkill; depending on B+ quality this cap even can be left out altogether.
 

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frankln

Member
2005-10-31 11:08 pm
The attached circuit is an excerpt from one of my projects. EM71 has an interesting non-linear, degressive characteristic somewhat suitable for output level (power) "metering", showing movements at low levels already, while not running into full reading too fast.

Tom

P.S.: The C3 value as shown is vast overkill; depending on B+ quality this cap even can be left out altogether.

Hi Tom i'm building this project.
[IMGDEAD]https://tezukuri-amp.org/evo/amp/6bm8z/6bm8z.pdf[/IMGDEAD]
Some suggestion for wiring magic-eye EM71?

thanks
Francesco

if the image do not open please go to this link:
Super triode connection Ver.1 6BM8 single ended. stereo power amplifier 2nd model