|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
For Sale Ads |
Use this form to submit comments directly to the Asylum moderators for this forum. We're particularly interested in truly outstanding posts that might be added to our FAQs.You may also use this form to provide feedback or to call attention to messages that may be in violation of our content rules.
Original Message
RE: Heaters in series?
Posted by Caucasian Blackplate on August 6, 2017 at 11:07:57:
The difference in voltage from grid to cathode will be greater in magnitude for the second stage than the first stage.
Fixed bias is called fixed bias because the bias voltage doesn't wander during operation (transitioning from class A to B for example).
If your filament supply has considerable capacitance from each end of the filament to ground, then you may be able to bias up the first stage to several volts, then put fixed bias on the second stage and still run it on the same filament supply without the two stages interfering with each other too much.