What do you think about this quiescent point for KT88 in push-pull ultra-linear operation?
Values for TWO tubes - Class A
DC Plate Voltage = 395 V
DC Screen Voltage = 395 V
Cathode Bias Resistor = 200 ohms
Peak AF Grid-to-Grid Voltage = 70 V
Zero-Signal DC Plate Current = 170 mA
Zero-Signal DC Screen Current = 12,5 mA
Effective Load Resistance, Plate-to-Plate = 5600 ohms
Screen Tapped at 40%
I use Cathode Bias without capacitor
Better ideas?
Thanks.
Values for TWO tubes - Class A
DC Plate Voltage = 395 V
DC Screen Voltage = 395 V
Cathode Bias Resistor = 200 ohms
Peak AF Grid-to-Grid Voltage = 70 V
Zero-Signal DC Plate Current = 170 mA
Zero-Signal DC Screen Current = 12,5 mA
Effective Load Resistance, Plate-to-Plate = 5600 ohms
Screen Tapped at 40%
I use Cathode Bias without capacitor
Better ideas?
Thanks.
What I think is that with the values you describe you will get about 30W in Class AB (not Class A) and that you should use separate 400 Ohm resistors on the cathode of each KT88, rather than a common 200 Ohm cathode resistor. All the data sheets and application notes are quite clear on this point.
Cheers,
Ian
Cheers,
Ian
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.