Sound Garage Tales

Where I show how I am attaching the EM80 Magic Eye tube to the inside of the Gabriel 1×12″ Stinger Combo. The hole I drill has a 1-3/8″ diameter using a Forstner bit. Then I am using a transparent plexi and a metallic shield screwed on the front valance.
The electrical connections are made via an octal tube socket connection on the side of the chassis. The electrical layout of the Magic Eye can be found here.

I couldn’t control myself. After seeing these cool demos of the Magick Eye tube, (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, 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).

The schematic I used is the one below, posted by Michael on the 18watt site.

I tapped the control voltage (signal) off one of the plates of the EL 84 tubes, and got the high voltage of about 250v off one of the filter caps.

Check this video out of how cool this can be!