The very first thing I noticed was that you are applying negative feedback from the output transformer primary
to the common cathode circuit of the phase splitter.
But hat is applying equal amounts of Both Positive Feedback and Negative Feedback.
Perhaps a little more detail of that area of your schematic would show otherwise.
The input stage? a triple stacked cascode?
It does not even have a marking of where the input signal is applied.
3 potentiometers for that stage? Is it a tone control circuit?
Perhaps you are using 4 primary windings to allow the screen voltage to be much lower than the plate voltage.
That raises the question of what is the ratio of screen windings / plate windings.
Depending on that %, the screen voltage of the "on tube" during signal might cause its tube current to go into near cutoff (while the other tube in AB1 is already in cutoff).
Is this a composite of different schematics all strung together?
I hope this is not your first tube amplifier build. It is a bit complex, and may require a lot of help.
to the common cathode circuit of the phase splitter.
But hat is applying equal amounts of Both Positive Feedback and Negative Feedback.
Perhaps a little more detail of that area of your schematic would show otherwise.
The input stage? a triple stacked cascode?
It does not even have a marking of where the input signal is applied.
3 potentiometers for that stage? Is it a tone control circuit?
Perhaps you are using 4 primary windings to allow the screen voltage to be much lower than the plate voltage.
That raises the question of what is the ratio of screen windings / plate windings.
Depending on that %, the screen voltage of the "on tube" during signal might cause its tube current to go into near cutoff (while the other tube in AB1 is already in cutoff).
Is this a composite of different schematics all strung together?
I hope this is not your first tube amplifier build. It is a bit complex, and may require a lot of help.
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Yeah it's supposed to be an instrument amp. Sorry if I put it in the wrong place. I hadn't figured out the exact number for the screen. I was going for ultra-linear. It is three inputs, I forgot to mark that. There is a bit of tone control. It is not a bunch of schematics tied together. I'll look at the negative feedback more. thanks!
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The schematic looks like it has quite a few last minute additions, little resistors and caps scribbled in below and near cathodes. Maybe best to wait until it has stabilized?
I moved it over to I&A hopefully some of the guitar amp guys can provide some advice/insights...Welcome to the forum. 😀