This circuit has a 100 dB dynamic We found it in a Popular Electronics from the 90s. Equivalent operational can be used.
I got this circuit from a magazine in 1967. The magazine no longer exists, but the circuit that...
Found in a Hands On Electronics of the 80s, this circuit makes use of a gas sensor of the time....
We found this circuit in the October 1993 Electronics Now magazine. The 4-channel circuit is...