Fired up the soldering iron last night and put together the Velleman Super Stereo Ear kit# MK136.
The stereo audio amplifier boosts sound 50 times and looks like fun kit to mess around with. Kit consists of 30 or so components that are soldered on a screen PC board. Assembly is straight forward and easy. Total build time was 90 minutes at a slow pace.
The kit is built around part number NE5532, dual low-noise high speed audio operational amplifier 8 pin dip. Per Fairchild Semi data sheet: The high small signal and power bandwidth provides superior performance in high quality Amp, all control circuits, and telephone applications. Kit also includes two microphones and a 3 cell battery holder that gets attached to the board. Only items required is head phones and batteries. I used a pair of old Walkman type head phones I had.
Time for the smoke test, a flick of the slide switch and the small LED came to life and turned a nice color red. Now with headphones in place and a slight turn of the potentiometer and the sounds around me came to life in stereo.
I took the stereo ear outside in the dark but only heard a car go by. I will have to take this out during the day and see what kind of gossip comes across. Maybe even add two paper towel type tubes to each microphone to aim in the direct of sounds in a distance.
The price is about $9.00 from J-Tron, Inc.
Will post more updates with this kit in the future.