I dumped the Cathode Follower. Check out the new design.

[riz]

Sorry for the hijack, and Chuck I'm not trying to be combative. I find your posts inspired and inspiring generally, and you've helped me a lot in the past. Went back and looked at what I did. It was on a phase inverter tube. Posting while tired, and breaking my rule of posting much here till I know what the hell I'm talking about. But I am here to learn. On my phase inverter, there's already a 2.7meg grid leak. What's another 470k? Enough about my stuff, I need to go back to the OP's circuit to stay in the conversation.

[Chuck H]

That sounds like he's explaining stages within the feedback loop. Not power tubes. You can use large values on power tubes though. Mesa has a couple of designs that use 220k with 330k bias feeds in fixed bias. But they also have 2.2M leak resistors right on the power tube grids to bring down the net load (a net load of 440k. 110k ABOVE the max for fixed bias). This is the largest commercial power tube grid stoppers I know of. I'll have to see something written that clearly states 1M grid stoppers are OK on power tubes before I'll believe it's advocated.

[riz]

Okay, gonna go back and chill over at my DUH thread where I belong! You've given me something to think about for a while, thanks! I look forward to being able to communicate with you at your level someday...

[leadfootdriver]

Also, the extra filtering suggested wasn't bigger filters. It was another can added to the end of the rail at the top of V1A plate load.

Yet another error in my schematic. The caps for v1-2 are to the left of the dropping resistor. I'll need to update that.

I think on my next build, I'll do separate caps for each triode like the TW.

[R.G.]

I'm curious.

What, exactly, do "so much more dynamic" and "with a strong frequency response" mean?

I know what "dynamic range" is and what the width, flatness, and so on of a frequency response are, but I'm not sure what "more dynamic" and "strong frequency response" are.

Any hints?

[leadfootdriver]

The cathode follower was really compressed. The parallel triodes weren't nearly as compressed, but it added a fatness to the tone along with a unique distortion. Now I'm on plate driven tone stacks. It has the most open, and articulate dynamics for this amp.

Maybe a plate driven tonestack would be to stiff for a fixed bias amp. But I don't know. These are the tools in my box right now. I'm still learning.