This circuit is from an 80's documentation, firing when the input voltage exceeds 5 V. The SCR can be the TIC106 need not have a heatsink.
Two potentiometers mounted at right angles, so that they can be operated by a lever, form a very...
This circuit is from a 2005 Linear Technology manual. The circuit uses an LT6700-3 and has an...
This circuit with RIAA equalization is from 1985 US documentation. The circuit has a flat response...