Re: Motorboating
Going back to Neil's experiments, I suppose you could use an ECL80 as a double triode driving a 6V6, and that should give sufficient gain for most applications. Connecting the pentode stage as a triode, with the screen grid connected directly to the anode, and I would advise using grid bias to avoid any instability problems caused by the common cathode. Thus the cathode would be connected directly to chassis, and the control grids of both sections would connect to chassis via large value resistors, 4.7-10 meg or so. Smaller value interstage caps would be used here to avoid grid blocking (0.005uf might be suitable for the basis of experimentation) , and if there is any instability decoupling in the anodes should solve the problem.
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