How Does a Bias-Shifting Tube Tremolo Work ? - YouTube
Delta-Trem Tremolo-Panner In-depth - Effectrode
Simplest tube tremelo
Add Reverb & Tremolo
RobRobinette Guitar Tube Amps - Here's an annotated schematic with the signal path for a more popular Gibson amp, the GA-40 version 3, 6V6 push-pull, 2 channel guitar amp with tremolo. | Facebook
The Valve Wizard- Tremolo Oscillator
HOMO ELECTROMAGNETICUS
Ultra Simple Tremolo (schematic and video) ///LeylandPedals : r/diypedals
Add Reverb & Tremolo
Add Vibrato (?) To Any Tube Amp! (1962) – Preservation Sound