This RIAA equalizer preamp was found in a 1990s schematic. The transistors are an old version of the BC549 that can be used as a replacement. Signal input and output cable must be shielded.
This circuit was discovered in an English publication in 1979. The circuit can still be assembled with...
This circuit whose transistors depend on the lamp current was found in Radio Electronics magazine from...
This two-transistor circuit was found in the January 1994 issue of Electronics Now magazine....