A tube commonly used as a tuning indicator in old radios. I had to try them out in my amps. So I plopped together a quick video to see the dramatic and cool visual effect. I will probably tweak some values but overall I am very happy with the visual effect. The circuit is nothing complicated. All you need is one of the many Magick Eye tubes existent out there, with many different beam patterns,
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that might need a slightly different pin-out connection, but all of them work in a main common way it taps in the path of the signal level of roughly 10 to 25 Volts (depends on the type of tube used), and a high DC voltage of something between 200 to 250 (B+). I used a Russian EM80/6BR5 I scored off Ebay. The EM80 tube has a U shaped fluorescent target and two rods connected to the anode, producing two angled shadows on the edge triggered by the control voltage (input signal). Aleks It should be driven off any audio circuit. The only thing is to get the signal to a decent level & impedance accepted by the input of the magic eye tube. Hello, I`m a bit late in seeing this but thank you for posting. I will add one of these in my next build as I already have a few purchased recently. I would like to point out that I am planning on using the 8 ohm tap at the speaker jack like taken here for negative feedback when used. Lower voltage & ratings for components instead of HT worries and with same parts count. Cheers! I have enjoyed your instructional videos and Sound Garage tales for a number of years. I have recently had an opportunity to acquire an EM80 tube and would like to incorporate it into my current amp project, much as you did with your great looking Stinger amp. I have not been able to find a source for the viewing window and trim for the head cabinet. Would it be possible for you to point me to a place where I could...
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