Does the switch put the lamp in and out of the CT to ground path?
If it does I believe that this is a 'soft start' circuit. The lamp is a resistor and the initial inrush current will be sunk by the filter caps so most of the voltage will be dropped across that 'resistor', so there wont be much voltage on the anodes as things warm up. After you wait for the filters to charge the anode voltage will rise nicely and a bit of anode current will allow the heaters to reach operating temp.
Flip the switch and away you go at full tilt. I believe that this was used in many gee-tar amps like the Vox...
If it does I believe that this is a 'soft start' circuit. The lamp is a resistor and the initial inrush current will be sunk by the filter caps so most of the voltage will be dropped across that 'resistor', so there wont be much voltage on the anodes as things warm up. After you wait for the filters to charge the anode voltage will rise nicely and a bit of anode current will allow the heaters to reach operating temp.
Flip the switch and away you go at full tilt. I believe that this was used in many gee-tar amps like the Vox...
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.