I do appreciate your honesty, and understand how tube rolling would make a difference. No doubt, I will be trying an RCA tube soon enough. RCA impresses me if the tube is well selected by the seller for performance, noise, and so forth.
FWIW, I changed the knobs on my unit to ones with markings. Pretty simple fix I'd say.
FWIW, I changed the knobs on my unit to ones with markings. Pretty simple fix I'd say.