We found this universal preamplifier circuit in a March 1994 Electronics Now. It has several types of equalization depending on the signal input.
We found this circuit in 2005 Linear Technology documentation. The integrated circuit is LT1787...
This circuit counts from 1 to 10 or 0 to 9 using as indicators common LEDs. The circuit can be...
We found this circuit in a Popular Electronics of the 90s. The circuit still uses light bulbs, but...