The operational amplifier for this tone control found in a 1977 Signetics manual may be the 741. The power supply must be symmetrical and the signal cables short. The bass gain is 20 dB.
The critical component of this project from a 1988 publication is the transformer. The final power...
September 2016 – At Mouser is available the new N channel MOSFETs PMGD175NEX from NXP for currents of 950...
This series motor control circuit was obtained from an old manual from the 80's. The SCRs must be...