Found in documentation from the 1980s, this circuit can have several adaptations to use modern transistors and LEDs instead of the lamp. The power supply voltage can also be changed.
The integrated circuit used in this stereo preamp is uncommon today, but the circuit can be...
Found in Linear Technology documentation, this amplifier requires a symmetrical power source and...
We found this circuit in a 1977 Radio Handbook. The lamp is the critical component, being 120MB at the...