This shield circuit is from an American documentation from 1969. The components can be modified according to the relay and power, and the coupler can be of a modern type.
This mechanical reverberator circuit for guitar was found in the February 1970 issue of Radio...
This circuit generates high pulses from a sinusoidal input, using SCRs for this purpose. The...
September 2016 - It can be purchased from Mouser Electronics the new ultraviolet high power LEDs...