Most if not all schematics and posts that talk about UL/Triode mode switches have been SE amps.. I have only seen one site mention moding a PP to add this functionality.
Does, or can a push pull amps characteristics be altered the same way?
Does, or can a push pull amps characteristics be altered the same way?
Got it, ordered them, have them on my bench...
Looking at slight variations in schematics noticed every darn one was SE...
Thought a little further education was in order. I have had a few things in life throw curve balls... The impression something was "obviously" intuitive, only to find out I clearly didn't have all of the information needed..
I take it from your response, that I should go for it...
In one popular design I see a 1.2K resistor off the tap, and another 100 ohm of the screen... than other designs I see only the 100 Ohm off the screen... This being a PP amp, and unsure if its 43%.. No voltages published, guess I will have to measure...
Too many unknowns for me and is why I freaking love this forum!
Looking at slight variations in schematics noticed every darn one was SE...
Thought a little further education was in order. I have had a few things in life throw curve balls... The impression something was "obviously" intuitive, only to find out I clearly didn't have all of the information needed..
I take it from your response, that I should go for it...
In one popular design I see a 1.2K resistor off the tap, and another 100 ohm of the screen... than other designs I see only the 100 Ohm off the screen... This being a PP amp, and unsure if its 43%.. No voltages published, guess I will have to measure...
Too many unknowns for me and is why I freaking love this forum!
"In one popular design I see a 1.2K resistor off the tap, and another 100 ohm of the screen... than other designs I see only the 100 Ohm off the screen... This being a PP amp, and unsure if its 43%.. No voltages published, guess I will have to measure"
I assume you are talking about the resistor between plate and screen in triode connection and the resistor between screen and UL tap of the transformer in UL connection. 100 ohms seems reasonable to me. I sometime use 0 ohm (no resistor). 1.2K to me is too high. It will effect linearity of the amplifier at that value.
The voltage you should be concern is the max screen voltage in the tube data sheet, since the screen has about the same voltage as plate in both triode and UL connection. Some tubes are overly conservative on max screen voltage but some are not.
I assume you are talking about the resistor between plate and screen in triode connection and the resistor between screen and UL tap of the transformer in UL connection. 100 ohms seems reasonable to me. I sometime use 0 ohm (no resistor). 1.2K to me is too high. It will effect linearity of the amplifier at that value.
The voltage you should be concern is the max screen voltage in the tube data sheet, since the screen has about the same voltage as plate in both triode and UL connection. Some tubes are overly conservative on max screen voltage but some are not.