0C3 Guitar Amp Controlled Smooth Sag

[enorbet2]

Thank you K O'Connor for your points and suggestions however I don't think I even implied that signal voltage was being directly controlled or tracked, so I disagree this was a "misstatement", It is the supply voltage conditions between Plate and Screen Grid that tracks and remains a fixed distance apart. It's not perfect as it is a difference not a percentage but the effect on sag is in fact quite noticeable.

I also disagree that a simple SS Zener Diode will directly sub for the 0C3. The characteristic of tubes/valves differs from SS in that SS has an extremely sharp knee while valves are softer. This is even true for rectifier type processes and can easily be measured and compared by scope'ing the output of a Full Wave Diode Bridge vs a common FW Tube/Valve. Yes the "DC" output voltage of the tube/valve is less than that of the SS "equivalent" but so is ripple and not just to the degree of the voltage difference but substantially greater. For trained ears it can also often be heard.

I'll post some photos and clips soon as well as the preamp schematic..